Welcome everyone to Alnylam's R&D Day 2022. I'm Christine Lindenboom, Senior Vice President of Investor Relations and Corporate Communications. We're pleased that you tuned in to hear about progress across our portfolio. Turning to our agenda, you can see we have a very exciting lineup of presentations scheduled during our time together, starting with some strategic perspectives on how we are building our business and executing towards our R&D strategy to achieve our goals. We will then turn to deep dives on different elements of our pipeline, spanning from our TTR franchise to progress with zilebesiran as a potential treatment for hypertension to our early and mid-stage pipeline before we close on perspective of what's percolating in the next wave of our R&D engine. A few quick reminders before we dive in.
This event is scheduled to run until 12:30 P.M. We've incorporated a break into the agenda. We'll be hosting 2 live moderated Q&A sessions during the meeting. To ask a question, please type your question into the Q&A box on your screen. A replay of today's session will be available on the investor's page of our website later today. During the course of today's meeting, we'll be making forward-looking statements. For additional information, I encourage you to review the most recent SEC filings posted in the investor section of our website. Finally, I'd like to thank our external speaker, Dr. Nitasha Sarswat, for joining us today. Share information about her disclosures here. With that, I'd like to turn it over to Yvonne Greenstreet. Yvonne.
Thank you, Christine. Good morning, everyone. It's a real pleasure to be here today for our annual R&D Day meeting and very inspiring to see the progress from our platform and anticipate what's in store in the months and years ahead. Our R&D Day is a capstone event for a year in which we've been celebrating our 20th anniversary as a company. We have a lot to celebrate. Since our founding in 2002, we have stayed focused on developing RNA interference as a new class of medicines and are proud today to have 5 RNAi therapeutics approved and helping patients around the globe. RNA therapeutics represents a rare opportunity to create a whole new class of medicines by harnessing a natural pathway to selectively target messenger RNAs that encode disease-causing proteins for destruction.
By silencing mRNA, RNAi therapeutics act upstream of existing therapeutic classes like small molecules and monoclonal antibodies. We've established a modular and reproducible approach to designing new medicines, with 100% of the human genome in theory available for targeting via RNAi, it represents a potential opportunity to significantly expand the ability to fight human disease. Leveraging this, we truly believe Alnylam is poised to be a top-tier biotech in the years to come. Take a step back for a moment. Let's reflect on our journey to date. While Alnylam was founded in 2002, the experiment that catalyzed the journey took a place a decade earlier in petunias. Fire and Mello described this mechanism a few years later, in another few years, Alnylam was born.
Alnylam was a company that was created from the aspirations of people who believed they could harness a breakthrough discovery in biology to treat disease in a better way, having recognized the limitations of current therapeutic approaches. However, the early days saw a lot of skepticism from the outside. Science was too new, the techniques unproven, and the technologies required not yet developed. We believed, we persisted, we persevered, and made progress and moved our platform along. Fast-forward to today. We're thrilled to have been able to overcome those initial hurdles, but it's important to highlight that we retain the innovative and scientific spirit that got us here and which will continue to drive success for Alnylam for many years to come as we evolve to target tissues beyond the liver and move into prevalent indications alongside rare diseases. You'll hear a lot about that today.
With a maturing commercial organization and boundary-pushing science, we've successfully established Alnylam as a fully integrated biotech company with a profile that's rarely seen in our industry. As I mentioned earlier, we have 5 RNAi therapeutics that were approved in under 4 years. ONPATTRO, GIVLAARI, OXLUMO, and AMVUTTRA, which we commercialize as Alnylam, and Leqvio, which is being marketed by Novartis. As of the 3rd quarter of 2022, the 4 Alnylam therapies were helping over 3,270 patients around the world. This success has been made possible by the commercial organization that we've built over the past few years, which has enabled us to establish a foothold in key global markets. We currently have a presence in 23 markets directly and 24 markets through distributors. We've also established end-to-end manufacturing capabilities to support operations.
Our global commercial presence will continue to grow as we advance the many exciting programs in our pipeline. These programs are in all stages in development and are addressing both rare and more common diseases. In addition, we'll continue to grow that pipeline with new targets and enhanced chemistries borne of this amazing underlying RNAi therapeutics platform that Aimee and Vasant will speak to in detail later this morning. Looking at our pipeline shown here, you can appreciate the diversity of opportunity across these programs. You'll hear about many of them today, including from Dion about our zilebesiran hypertension program, where we look forward to Phase 2 data next year. You'll also hear from John about our TTR franchise and the outlook there as we look to expand the ONPATTRO label following positive APOLLO-B results, and anticipate results from the vutrisiran HELIOS-B trial in early 2024.
Our guest key opinion leader, Dr. Sarswat, will also highlight the unmet need facing patients with ATTR cardiomyopathy. Weinong Guo will share updates on our earlier stage programs, including ALN-KHK for metabolic liver disease and type 2 diabetes, ALN-HSD, and ALN-PNP for NASH, and our first CNS program, ALN-APP for Alzheimer's disease and cerebral amyloid angiopathy, where we expect initial Phase 1 data early next year. You'll also hear about some strategic pipeline prioritization decisions that we've made. Actually, we'll talk through our rationale with regard to pausing development of Cemdisiran in IgA nephropathy and discontinuing the ALN-XDH in gout and lumasiran for recurrent renal stones. As you know, we have a history of charting our progress with bold 5-year goals. In early 2011, we launched our Alnylam 5x15 to bring 5 RNAi therapeutics into the clinic by the end of 2015.
We exceeded that goal by delivering eight clinical programs by the end of 2015. In early 2015, we launched our Alnylam 2020 strategy to bring three or more RNAi therapeutics to the market by the end of 2020. We also exceeded that goal by bringing 4 programs to market and doing so on a global basis. In early 2021, we launched our third five-year goal installment with our Alnylam P5x25. We're making really good progress in delivering on these goals and believe that Alnylam can become a top biotech company, developing and commercializing transformative medicines for rare and prevalent diseases for patients around the world, driven by a high-yielding pipeline of first and or best-in-class product candidates from our organic product engine, all while delivering exceptional financial results.
There are a few fundamental key growth drivers for the company, which are listed here. First is the potential near-term expansion of our ATTR amyloidosis franchise, where we aim to become the global leader in delivering impactful and highly differentiated medicines for patients with all forms of ATTR amyloidosis. The second key growth driver is our expansion beyond rare diseases into more prevalent indications. You know, the pharmacological features of RNAi therapeutics are uniquely suited for the treatment of chronic prevalent diseases where durable effects enable infrequent dosing to maximize adherence and where clamped pharmacology creates the potential for improved efficacy and outcomes. The third growth driver comes from our sustainable innovation engine.
As you know, we'll hear more about today, we continue to maintain our leadership in RNAi and push the boundaries of the technology, bringing forward new platform enhancements and novel therapeutic targets, taking us beyond 2025. Ultimately, at Alnylam, we know that the secret sauce of our success over these past 20 years will continue to be the key to our success going forward, and that's our people and culture. This is foundational to realizing our vision of building a top-tier biotech company, and we're proud of what our commitment to this mission has achieved to date. As seen here, we continue to be recognized across pharma and biotech and other industries for multiple elements of our culture, including our leadership in scientific innovation, diversity, equity and inclusion, social responsibility, and first and foremost, a steadfast commitment to the patients we serve.
With that, I'll turn it over to Akshay Vaishnaw, our President, to set the stage further for today's event. Thank you very much.
Thank you, Yvonne. Good morning to everybody. Let me also welcome all of you to our annual R&D Day. I want to start with an overview of our strategy and what you can expect to see from my colleagues during the day that follows. Alnylam was founded in 2002 based on the discovery of RNAi in human cells by one of our founders, Tom Tuschl. The top left panel shows the RNAi-mediated silencing of a human gene, lamin in this case, for the first time. Over the last 20 years, we've focused our R&D strategy to convert that in vitro observation into a reality for patients. The strategy has consistently had 3 components: the selection of a target organ, the presence of relevant genetically validated disease-causing genes in that organ, and finally, an appropriate system to deliver RNAi therapeutics to the target tissue.
In turn, that strategy, which began with addressing liver targets, has to date led to the five approved RNAi therapeutics we have today. We continue to be guided by this strategy and look to expand beyond liver targets to other organs such as the brain, eye, muscle, and other tissues. Our R&D approach has been very productive, and today, in addition to the five approved RNAi therapeutics, we have a pipeline of 12 clinical development programs across 4 therapeutic areas with targets in multiple tissues, including the liver and the central nervous system. We also have a rich discovery engine and many interesting opportunities in preclinical development. ATTR amyloidosis represents our most advanced franchise. This is essentially a single disorder caused by the deposition of misfolded transthyretin or TTR, resulting in systemic amyloidosis, most often affecting peripheral nerves, the heart, or often both.
The disease can result from mutant or wild type TTR, but we believe that all the manifestations can be addressed by lowering circulating TTR levels by an RNA mechanism. The patisiran and vutrisiran Phase 3 studies, APOLLO and HELIOS-A, respectively, led to the regulatory approvals of ONPATTRO and AMVUTTRA. Importantly, not only did these studies demonstrate the impact of TTR lowering via our drugs on the peripheral neuropathy, but exploratory endpoints from these studies, as well as findings from investigator-initiated studies, also showed the potential for cardiac benefit. Earlier this year, we were thrilled that the encouraging exploratory cardiac findings from prior studies were validated by the positive findings for patisiran in ATTR cardiomyopathy patients in the APOLLO-B study. In this case, our seventh positive Phase 3 study in the last 5 years.
My colleague, John Vest, is going to review all the latest data from our TTR portfolio and also discuss our enhanced confidence in HELIOS-B, where we're studying vutrisiran in ATTR cardiomyopathy patients. The development and approval of inclisiran by our partner, Novartis, has illustrated the power of infrequently administered RNA therapeutics to achieve tonic control in a prevalent disease, namely hypercholesterolemia. It has also been exciting to see preliminary data from the inclisiran Phase 3 program showing translation of reductions in LDL cholesterol, shown on the left, to lower rates of major cardiac adverse events shown on the right. Even more importantly, the encouraging efficacy and safety results from the inclisiran clinical development program have inspired us to develop what we believe could be a transformative approach to another common disease, resulting cardiovascular morbidity and mortality, namely hypertension. zilebesiran is our investigational RNA therapeutic for hypertension.
Clinical data from the Phase 1 study have shown the impact of a single dose of zilebesiran on its target angiotensinogen, shown on the left here. On the right, you see associated reductions in systolic blood pressure with over 20 millimeters reductions, which were sustained 24 weeks after drug administration. My colleague, Dion Zappe, will share the rationale for the development of zilebesiran, full Phase 1 data encompassing the safety and efficacy of single and multiple doses, the interesting and important pharmacodynamic effects which distinguish zilebesiran from current oral RAS inhibitors, and the progress with our Phase 2 studies, KARDIA-1 and 2. Separately, our mid an early stage, pipeline continues to progress both with new data and new INDs. My colleague, Weinong Guo, will discuss these additional opportunities with you, including, but not limited to, exciting data from multiple studies for ALN-HBV02 conducted by our partner Vir.
Positive Phase 1 proof of mechanism data from our first NASH drug, ALN-HSD, in conjunction with Regeneron. ALN-APP, our first CNS drug in development for Alzheimer's and cerebral amyloid angiopathy, which is currently in Phase 1 and where we expect to have initial data in early 2023. Finally, ALN-KHK for type 2 diabetes, where we're on track to file a CTA imminently. Our focus R&D strategy, driven by the selection of genetically validated targets, has led to an impressive probability of success rate or POS. As you can see on the right of this slide, currently our cumulative POS from Phase 1 to 3 is a remarkable 62%, which is far greater than industry averages around 5%-10%. In spite of this enviable historical POS rate, it's critical that we remain disciplined in making important data-driven pipeline decisions.
Some current examples of this type of pipeline prioritization that we're sharing today include the following. For Cemdisiran monotherapy earlier this year, we reported impressive Phase 2 IgA nephropathy data showing well over 30% reduction in proteinuria. Whilst we find this data encouraging, Regeneron recently decided not to participate in further development of the Cemdisiran monotherapy program. As a result, we will now take some time to consider options for the best path forward for Cemdisiran in this indication. Our Phase 1 data with ALN-XDH in development for gout are now available and show an encouraging safety profile with some evidence of change in serum urate. However, the degree of serum urate lowering we have observed does not reveal a transformative potential for the drug in gout, and as such, we have decided to terminate the program.
Our Phase 2 study of lumasiran in patients with recurrent kidney stones has been ongoing this year. In the early screening phase of the trial, with a significant number of patients screened, it became clear that the proportion with elevated urine oxalate is lower than originally thought. The hypothesis that reducing elevated urine oxalate in recurrent kidney stone patients could be beneficial is an important one. With the current screening data, we will terminate the Phase 2 study and assess whether a small trial with a single investigator is warranted. The pipeline prioritization decisions I just shared with you illustrate the importance of exercising discipline when it comes to building a robust and high-yielding pipeline. Another key factor in the further growth of our pipeline is our sustainable innovation engine.
For example, as shown on the left here, my colleague, Aimee Deaton, will discuss how we have made great progress with our genetics program under the umbrella of the Alnylam Human Genetics, where we have discovered multiple novel targets in recent years, and where she'll discuss an exciting new liver target today. As importantly is leadership in our platform and delivery sciences. My colleague, Vasant Jadhav, will discuss platform advances such as IKARIA, GEMINI, and REVERSIR. Respectively, these approaches, we believe, will allow us to achieve annual dosing, enable us to hit multiple targets simultaneously, and also provide the flexibility to reverse an RNAi effect if needed. The further advancement of our platform and reaching the full potential of RNAi therapeutics involves achieving delivery to new tissues, as shown on the right here.
Our experience and know-how of developing conjugates for the liver and CNS is serving us well and accelerating our experimental progress in getting RNAi therapeutics to many new tissues such as muscle, adipose, and the heart. Vasant is going to discuss these important advances with you. Ultimately, our scientific leadership should drive leadership in the clinic. A good example of that is shown here via our TTR portfolio. Bottom left, we started with patisiran, an IV Q-three weekly drug for hATTR PN. With platform advances and the development of the GalNAc conjugate technology for liver delivery, we progressed to vutrisiran, a subQ quarterly administered drug for hATTR PN, which also has the potential to be administered biannually, and where its profile is very suitable for development of not just hATTR PN, but also ATTR CM.
Finally, top right, one of our most recent platform developments, IKARIA, allows the use of chemical modifications to drive potentially to annual subQ administration with our drug ALN-TTRsc04, which should enter Phase 1 at or around year-end. With our chemistry and delivery platforms, we aim to drive continued and concerted innovation with progressively better product profiles to meet the needs of patients, doctors, and the entire health ecosystem. We feel confident we can efficiently and rapidly use similar approaches as shown here for other targets and indications in the current and future Alnylam pipeline. Let me close by sharing our 2023 goals, which show that we have a very exciting year ahead. Beyond progress getting our approved drugs to more patients, we look forward to FDA approval of patisiran for ATTR-CM in late 2023, pending regulatory review, and 10 clinical readouts from proprietary and partner-led programs.
Specifically, these proprietary readouts include a potential sNDA submission for vutrisiran in early 2023, pending data on a biannual dosing regimen. Top-line results from the Phase 1 study of ALN-TTRsc04 in late 2023. Top-line results from KARDIA-1 and 2 studies of zilebesiran. ALN-APP top-line Phase 1 results in patients with early onset Alzheimer's disease in early 2023. Top-line Phase 1 results from our ALN-KHK program for type 2 diabetes in late 2023. We also anticipate progress with our alliance programs, including additional Phase 3 hemophilia results for Fitusiran, partnered with Sanofi. HBV and HDV Phase 2 data for ALN-HBV02, partnered with Vir Biotechnology. The initiation of the ALN-PNP Phase 1 NASH study by Regeneron. In closing, I want to say that Alnylam's R&D strategy continues to flourish as we make advances with our suite of liver-directed programs.
The future looks even brighter as we await progress with our CNS efforts and leverage our significant scientific strengths to address new targets and tissues. With that, I'd like to thank you for your attention and hand it over to my colleague, John Vest, to review the exciting progress and future growth potential of our TTR franchise. John?
Thanks, Akshay. Hello, everyone. My name is John Vest. I'm the Global Clinical Lead for our TTR franchise. On behalf of the TTR team, I am very pleased for the opportunity today to update you on the programs and our plans to continue to expand the franchise. Additionally, Dr. Nitasha Sarswat, an ATTR amyloidosis treating physician and clinical trialist, has also joined us today to share thoughts on the unmet need in the patient population, as well as her perspective on the future of treatment in the field. We now have three RNAi therapeutics in our TTR amyloidosis franchise. On the left, you see ONPATTRO or patisiran, which was the first ever approved RNAi therapeutic, with U.S. approval in August of 2018 for the treatment of the polyneuropathy of hereditary ATTR amyloidosis based on the landmark APOLLO Phase 3 study.
Patisiran is also currently in further clinical development in our APOLLO-B Phase 3 study, for which we have recently announced positive Phase 3 results. More on that later in the presentation. Vutrisiran, an RNAi therapeutic that gained its first approvals this year as AMVUTTRA, utilizes ESC-GalNAc conjugate chemistry. It is also under further development in the ongoing HELIOS-A and HELIOS-B Phase 3 studies. Vutrisiran has a very compelling product profile with subcutaneous administration of a 25 mg dose once every 3 months. We are also evaluating a potential additional dosing regimen of 50 mg once every 6 months. Finally, ALN-TTRsc04 is the newest program within our franchise. Like our other programs, this RNAi therapeutic specifically targets transthyretin mRNA. However, TTRsc04 utilizes our new IKARIA platform chemistry in its design, and we believe has the potential for once annual dosing and greater than 90% serum transthyretin reduction.
More on this later in the presentation. Collectively, it is our belief that these three programs will support Alnylam's vision to be the leading TTR amyloidosis franchise and position us for sustainable market leadership. Collectively, as illustrated here, we intend to continue to build the TTR franchise over time, pending positive data readouts for the studies I will be covering during the presentation and regulatory agency approvals. We aim to have ONPATTRO, AMVUTTRA, and ALN-TTRsc04 expand across the ATTR amyloidosis patient population over the coming years. Before we talk about specific studies or results, I'd like to briefly review the disease of TTR amyloidosis and our therapeutic hypothesis. TTR amyloidosis is a rare, progressively debilitating disease caused by misfolded transthyretin protein that accumulates as amyloid deposits in multiple tissues, including the heart, nerves, and GI tract, typically resulting in polyneuropathy and cardiomyopathy.
As with most rare diseases, the true prevalence is difficult to know. We believe there are approximately 50,000 patients worldwide with the hereditary form of the disease, where the patient carries a TTR gene variant. Patients without a transthyretin variant can also accumulate misfolded transthyretin protein in tissues, often associated with advancing age, and this leads to wild type ATTR amyloidosis. Prevalence estimates for this patient segment are significantly larger, perhaps 300,000 patients worldwide, though some estimates are much higher. Both the hereditary and wild type forms of disease may present with multi-system involvement and a high burden of disease that is often fatal.
Our therapeutic hypothesis, which has remained consistent since we began working in this space over 10 years ago, hypothesizes that utilizing an RNAi therapeutic to dramatically reduce the production of the disease-causing transthyretin protein in the liver will prevent continued amyloid deposition and potentially allow the body to remove existing deposits, ultimately halting or improving certain manifestations of the disease. Other treatment modalities attempt to interfere with the disease cascade at later points after the transthyretin protein has been made and is circulating throughout the body. We strongly believe that suppressing the production of both variant and wild type transthyretin protein in a highly potent and reversible manner may prove to be the best approach to treating this disease, and we have designed our TTR targeting RNAi therapeutics to do just that.
This therapeutic hypothesis was first validated in the polyneuropathy of hereditary ATTR amyloidosis with the original APOLLO study. As we'll discuss later in this presentation, we sought to validate this therapeutic hypothesis in patients with ATTR amyloidosis with cardiomyopathy in a now seen positive study results from APOLLO-B Phase 3 trial. We would like to focus this presentation largely on our plans to, and efforts to expand RNAi therapeutics beyond polyneuropathy. However, I would like to first briefly recap our exciting accomplishments in hereditary ATTR amyloidosis with polyneuropathy that unfolded over the course of 2022, as we are enormously proud of the progress that we made in bringing forward AMVUTTRA as a treatment option for these patients. To this end, we'll briefly take a look back at the HELIOS-A study of vutrisiran.
You may recall, HELIOS-A is a study of vutrisiran in patients with hereditary ATTR amyloidosis with polyneuropathy. 164 patients were randomized 3 to 1 to either vutrisiran 25 milligrams quarterly or patisiran 0.3 milligrams per kilogram once every 3 weeks, which served as a reference comparator. The study compared vutrisiran to the placebo arm of the APOLLO study as an external control for the primary and most secondary endpoints. The primary endpoint was the Modified Neuropathy Impairment Score +7, mNIS+7. Quality of life is assessed by the Norfolk Quality of Life questionnaire, was a key secondary endpoint. Additional secondary endpoints assessed a wide range of important disease manifestations, including ambulatory function, nutritional status, and disability.
The study design included a primary analysis at month 9 and an additional analysis at month 18, where this full spectrum of clinical assessments were analyzed as secondary endpoints. The study is ongoing in a randomized treatment extension comparing the serum transthyretin reduction of the 25 milligram quarterly regimen to the 50 milligram biannual regimen. Please note that our timeline to share data for the treatment, or from this treatment extension has shifted, from the end of 2022 to early 2023, as we're awaiting the full data set. Here we're recapping key efficacy results from the study. The analysis for the primary endpoint was at month 9. The primary endpoint of mNIS+7 and the key secondary endpoint of Norfolk Quality of Life demonstrated a clinically and statistically significant improvement compared to the external placebo arm from the APOLLO study.
This beneficial treatment effect persisted through month 18. In data not shown but previously presented, at the month 18 analysis, significant improvement with vutrisiran compared to external placebo was also observed for all other secondary endpoints, including ambulatory function assessed by the 10-Meter Walk Test, nutritional status assessed by modified body mass index, and disability assessed by the RODS instrument. Transthyretin reduction with vutrisiran was also confirmed to be non-inferior to the within study patisiran arm based on pre-specified criteria. Furthermore, in exploratory analyses of cardiac parameters, patisiran demonstrated favorable changes in NT-proBNP and certain echocardiographic parameters relative to external APOLLO placebo. Importantly, as previously presented, patisiran also demonstrated an acceptable safety profile during the 18-month treatment period.
These data from the HELIOS-A study have been the basis of our regulatory filings around the world. We are absolutely thrilled that over the course of 2022, we have gained regulatory approval with AMVUTTRA for hereditary ATTR amyloidosis patients with polyneuropathy in the U.S., Europe, the U.K., Japan, and just earlier this month, Brazil as well. To emphasize impressively, approvals from 5 regulatory bodies have been secured in just the past 6 months. Of course, we intend to continue to expand the commercial AMVUTTRA footprint for hereditary ATTR amyloidosis with polyneuropathy in 2023 and beyond. Before we turn our attention to cardiomyopathy, as a segue, I would like to highlight another notable study readout that occurred this year from our multicenter Phase 4 observational study.
The Phase 4 observational study evaluated the effectiveness of patisiran in patients with polyneuropathy of hereditary ATTR amyloidosis with a V122I or T60A variant, which are both variants that are frequently associated with cardiomyopathy manifestations of hereditary ATTR amyloidosis. The patient population was receiving commercial patisiran and was characterized in one of three cohorts. The prospective cohort, where patients are naive to patisiran at the time of enrollment and intend to soon initiate therapy. The ambispective cohort, where patients have been receiving commercially available patisiran for less than 12 months at the time of enrollment. The retrospective cohort, which includes patients who received commercially available patisiran for more than 12 months. The primary endpoint of the study was the proportion of patients with stable or improved polyneuropathy disability score, PND score, at 12 months relative to baseline.
A robust set of secondary endpoints was also evaluated, including Norfolk Quality of Life, COMPASS, modified body mass index, NT-proBNP, and the Kansas City Cardiomyopathy Questionnaire. The study completed enrollment in June of 2021 with a total of 67 patients. These data were intended to complement the results of the APOLLO study as they further expand our understanding of the potential benefit of patisiran in hereditary ATTR amyloidosis patients with polyneuropathy due to these specific genetic variants where limited data are otherwise available. The study results demonstrated that patients with a V122I or T60A variant, which again are variants historically associated with cardiomyopathy, also had evidence of polyneuropathy at baseline, as demonstrated by impaired quality of life, autonomic dysfunction, and a wide range of ambulatory dysfunction.
The primary endpoint of the study was met with 93.3% of patients demonstrating stabilization or improvement from baseline in Polyneuropathy Disability score after 12 months of patisiran treatment. As shown here, patients on patisiran treatment also demonstrated evidence of improvement from baseline in 2 key exploratory measures of quality of life. The Norfolk Quality of Life questionnaire, which is typically used to assess quality of life in patients with polyneuropathy, as well as the Kansas City Cardiomyopathy Questionnaire, which is typically used to assess health status and quality of life in patients with cardiomyopathy. Furthermore, patients on 12 months of patisiran treatment also demonstrated exploratory evidence of improvement from baseline in measures of autonomic symptoms as assessed by the COMPASS-31 instrument.
Including improvement in the orthostatic intolerance domain of the COMPASS-31, which reflects a particularly debilitating aspect of this disease for many patients. As noted in the final bullet here, nutritional status as measured by modified body mass index also improved in patisiran-treated patients, with an improvement from baseline observed at month 6 and maintained through month 12. Patisiran demonstrated an acceptable safety profile consistent with the known profile of the drug. 11 patients were hospitalized during the study, and 3 patients subsequently died. All hospitalizations and deaths were considered unrelated to patisiran. In summary, we're very pleased to be able to bring more data to the field describing the real-world patisiran experience in patients with V122I and T60A variants. Patients with these variants, which are historically associated with cardiomyopathy, also experienced polyneuropathy at baseline.
The primary endpoint of the study was met, 93.3% of patients demonstrated stabilization or improvement from baseline in polyneuropathy disability score after 12 months of patisiran treatment. Importantly, patisiran demonstrated an acceptable safety profile. We will now move on to look forward and talk about our ongoing expansion into ATTR amyloidosis with cardiomyopathy and beyond. We feel extremely encouraged about the potential for vutrisiran and patisiran in ATTR amyloidosis with cardiomyopathy. While we now have data from APOLLO-B, we embarked on our cardiac program in the context of a sound foundation of evidence, giving us confidence in the potential for RNA therapeutics in this space. Thus, the results from our cardiac studies come in the context of a rich background of supportive evidence.
As we have presented previously, the original APOLLO study of patisiran demonstrated exploratory evidence for improvement in cardiac biomarkers, echocardiographic parameters in ambulatory function with patisiran treatment compared to placebo. The significance of these improvements in cardiac assessments was supported by a post-hoc analysis of safety data of the APOLLO study, which, as shown on the left, demonstrated a roughly 50% reduction in the composite rate of all-cause mortality and hospitalization over the course of this 18-month randomized controlled study. These initial data of the APOLLO study were complemented by data published by the National Amyloidosis Centre in London from 32 patients with hereditary ATTR amyloidosis with cardiomyopathy.
At 1 year, there was evidence of a reduction in cardiac amyloid burden assessed by extracellular volume fraction in patients who received patisiran, a majority of whom also received diflunisal, compared to retrospectively matched control patients who received no disease-modifying therapy. The patisiran-treated patients also demonstrated substantial improvements in six-minute walk test and NT-proBNP compared to the control group. Overall, the authors described these data as demonstrating, quote, compelling evidence of substantial amyloid regression, end quote. These exploratory and post-hoc analyses, we believe collectively demonstrate a consistency of findings across a wide spectrum of parameters and provide important context and confidence for the hypotheses we're pursuing in our cardiac studies.
Indeed, with our ongoing studies in ATTR amyloidosis with cardiomyopathy, APOLLO-B with patisiran and HELIOS-B with vutrisiran, we are seeking to validate this hypothesis that TTR reduction with an RNA therapeutic will stabilize disease progression and result in clinically meaningful benefits and ultimately improved outcomes. APOLLO-B has now read out and we believe provides compelling data to support patisiran as a potential treatment option, pending regulatory approval based on its important beneficial impact on how patients feel and function. HELIOS-B is our ongoing study of vutrisiran, which is designed to provide outcomes data. The study is fully enrolled and on track for top-line readout in early 2024. We will discuss APOLLO-B and HELIOS-B further later on in the presentation, but I'd first like to turn the presentation over to Dr. Nitasha Sarswat, Assistant Professor of Medicine and Director of the Cardiac Amyloid Program at the University of Chicago Hospitals, for an update on the current state of ATTR amyloidosis.
Thank you, Dr. Vest. Today, I'm privileged to discuss with you the state of ATTR amyloidosis with cardiomyopathy. My disclosures. I am a consultant of Alnylam, and my institution is receiving compensation for this presentation. I am also an investigator on the APOLLO-B and HELIOS-B studies, which are sponsored by Alnylam. I'm going to start by discussing a very familiar case, and this is a type of patient that certainly I see all day long, every day. Patient M.D. Is a 76-year-old male who has been very active throughout his life, who loves traveling, biking, traveling throughout Europe. Over the last few years, he had developed worsening dyspnea and fatigue and didn't feel like he could keep up with his wife on a hike.
He did have a history of spinal stenosis, bilateral carpal tunnel disease, and actually had had a right carpal tunnel release about 8 years ago. He also has a history of atrial fibrillation, hypertension, and some foot numbness. On exam when I met him, he had an elevated jugular venous pressure of 8 centimeters, suggesting volume overload, an irregularly irregular heartbeat. His extremities were warm and well perfused, but he did have 1+ edema bilaterally. He was noted to have a significantly elevated pro-BNP and troponin and an echocardiogram and a cardiac MRI at the time I met him that were both consistent with amyloid, amyloidosis of the heart.
When I met him in clinic, he had been reading on the Internet that amyloid was a death sentence, and certainly, we had a long discussion regarding the disease, the history of the disease, recent changes, and some new hope on the horizon for a patient like him. After this discussion, we proceeded with an AL rule-out, which included an SFLC, UPEP, and light chains that were all normal. I sent him for a PYP, a technetium PYP, which showed significant amyloid deposition. It was a grade 3 and did show a heart to lung ratio of 1.8. At that point, we also did genetics, specifically looking for a mutation in the TTR mutation, and they were negative as well.
He returned to clinic for a discussion. At that point, we had a long discussion regarding the idea that we had non-invasively now diagnosed cardiac TTR amyloidosis from our diagnostic algorithm and that he specifically had wild-type transthyretin cardiomyopathy. We had a review of medication options that were available to him and the data that we have thus far and really had a nice informed discussion. This is common in practice for patients with wild-type TTR to review medication options and really review the options that we have to try to improve mortality, morbidity, and how we can make them feel better. That's gonna launch us into this discussion. The big things are how big is this population that's impacted by the disease that would potentially benefit from further treatments? What is the unmet need in terms of ATTR amyloidosis treatment?
We'll continue to come back to patient M.D., who is a patient whose life is affected by discussions like we're having today. First, why is heart failure so important? Heart failure, again, is the presenting symptom in the majority of these patients. Heart failure affects nearly 6.2 million Americans and is the primary diagnosis for a hospital discharge in about 1 million. A secondary diagnosis in about 2 million hospitalizations annually. By 2030, more than 8 million people in the United States, we think 1 in every 33 will actually have heart failure. This plays in to really understanding the burden of the disease and just how common this disease is. What we see from heart failure is that this is truly an epidemic. The cases are rising and rising, and this is not being mitigated and going away.
You get a sense of just how many people throughout the world are really going to be affected by heart failure as time goes. If we take all of those patients that have heart failure, and why is this relevant to this particular conversation, is that out of those people, slightly more than half of them actually have heart failure with preserved ejection fraction. Of those with heart failure with preserved ejection fraction, it's estimated that anywhere from 13%-29% of those patients actually have cardiac amyloidosis. There was a recent study that struck me from Abou-Ezzeddine, which looked at over 1,000 patients with an LV wall thickness of 12 mm, which is actually quite common.
What we found is that about 10% of men and 2.2% of women actually had TTR cardiomyopathy. Some other relevant data to understand the population. In a recent autopsy study, we found that 25% of patients greater than 80 actually had some level of TTR deposition in the heart. Of those, two-thirds had left ventricular involvement, and we saw significant cardiac involvement in anywhere from 8%-16% of people greater than 80 years old. While this is an autopsy study and certainly can have flaws, that really just gives us a sense of just how many people actually have a level of amyloid deposition. Similarly, there was a recent study of patients undergoing TAVI for aortic stenosis, they did a technetium PYP looking for amyloid deposition in these 150 patients.
In fact, 16% of them had evidence of true significant amyloid deposition. Similarly, when we look at the population of patients admitted in the hospital, which we talked about was a very growing number of patients, we see that heart failure with preserved ejection fraction in the hospital, about 13% of them actually probably have a level of TTR cardiac involvement. Again, just to hit home, this is affecting a large burden of patients, and this is not going away. Those numbers are just going to continue to increase. We think about 155,000 people or 5% at least of the estimated HFpEF prevalence have ATTR, though we may have milder deposition in many others.
The valine isoleucine mutation, which we see in, is the largest common mutation in the TTR gene in the United States, has been found in 10% of African Americans over the age of 65 who have heart failure. We do know that the survival of these patients with wild-type TTR cardiomyopathy has also been observed as with worsening declining NYHA functional classes. We know that patients who have worsening NYHA functional classes is an independent risk factor for adverse cardiovascular outcomes that include conduction disease, hospitalizations, and stroke. There is this population of significant heart failure with advanced symptoms, NYHA 3 to 4, and those are the people that are often untreated and that are going to have the worst outcomes. Let's talk about this unmet need of patients with TTR cardiac amyloidosis. What are our options?
When I talk about the patient, MD, that we had met, what is this informed discussion I have? Our therapeutic approaches. The first thing we can do is actually stabilize the TTR tetramer, and we can do this in one of three potential ways. The first is tafamidis, which is the only FDA-approved treatment for wild-type or hereditary amyloidosis in adults, and reduces CV mortality and CV-related hospitalizations. There is some data for diflunisal, and we'll discuss this. And then we also have acoramidis, which is an investigational therapy for the potential treatment of cardiomyopathy and TTR amyloid, which has completed a Phase 3 trial. The second options are reducing TTR production. We have several opportunities here.
The first is patisiran, which right now is approved for the treatment of polyneuropathy of hereditary TTR amyloidosis and is an investigational therapy for the potential treatment of cardiomyopathy. Similarly, vutrisiran is now approved for the treatment of polyneuropathy for hereditary TTR amyloid but is investigational for the potential treatment of cardiomyopathy. We have inotersen, which is approved for the treatment of polyneuropathy or hereditary transthyretin-mediated amyloidosis in adults. eplontersen, which is an investigational therapy as well for the potential treatment of polyneuropathy of hereditary TTR and an investigational therapy for the potential treatment of cardiomyopathy of TTR amyloidosis. Other options may include, there is some data for doxycycline and TUDCA or tauroursodeoxycholic acid.
Certainly a very hopeful potential therapy going forward is CRISPR gene editing, though we're certainly trying to understand the role that this new technology can potentially have for our patients. We talked about these therapeutic options, and what we see is that right now there are these approved therapies for polyneuropathy but very minimal approved therapies for cardiomyopathy. Well, why is that? When we look at the underlying pathophysiology of TTR amyloidosis, we understand that there's this tetramer that becomes unstable. I always tell patients it's like a 4 leaf clover that falls apart into one-leaf clovers. Those one-leaf clovers develop misfolded proteins that come together to form amyloid fibrils. Those amyloid fibrils can deposit in the heart, in the nerves, and in the autonomic nervous system. While the manifestations may be different, it's all the same underlying pathology and all one disease.
Yet our treatments thus far have only targeted a fraction or a portion of the actual symptoms and manifestations of the disease. Let's just go back to our specific patient. What are his options right now? Again, he has wild-type transthyretin cardiomyopathy. His really only option at this point is a stabilizer. He cannot afford his tafamidis copay and does not qualify for any patient assistance. Again, there are these patients whose needs remain unmet by these current treatments because of affordability and access. Then we have current TTR silencer therapies that are approved only for the hereditary neuropathy. Similarly, what about those patients that get stabilizers and don't respond and who continue to significantly progress despite therapy with a stabilizer?
We also know that despite these therapies that are available, quality of life remains a significant issue, and a lot of patients are very impacted on a day-to-day basis despite current therapy. Let's go through again what we have. We know that tafamidis, again, which is approved for wild-type and hereditary cardiomyopathy, in the ATTR-ACT trial, showed a significant improvement in mortality. We see those curves start to separate, and we know that the patients who were on tafamidis did better than those who were on placebo. We also see that there's still a continued progression of disease despite therapy. When we look at the subgroup analysis from this ATTR-ACT study, we see that both hereditary and wild-type patients were benefited by tafamidis therapy.
When we look at NYHA classes, again, the healthier patients were the ones that benefited. The Class three patients, there was a questionable benefit, and the Class 4 patients were excluded from the study. What do we have to offer a patient who right now has Class three symptoms, who may or may not benefit for tafamidis or who cannot get tafamidis? This is actually a study that we did looking at patients in a community system that were diagnosed with TTR amyloid. We looked at 107 patients that were about 84 years old. The majority were men, and only 59% of them were actually on tafamidis. Those patients who were on tafamidis did better. The people that were not on tafamidis tended to be the patients that had, were sicker.
Again, the NYHA 3s and 4s. The most common reasons the patients were not on tafamidis were because of delays in obtaining the drug or financial barriers. Which is 59% of the people and about 20% of people that were just too sick and had NYHA Class IV heart failure. The patients taking tafamidis had a higher survival, which is similar as we would expect with, compared to people who are not getting it, similar to what we would expect with the ATTR-ACT trial. We see that there was a survival benefit. What are our other options for people who can't get to, who can't get tafamidis? diflunisal has been studied more retrospectively, not in a prospective randomized controlled trial. diflunisal is essentially an NSAID, a non-steroidal anti-inflammatory drug, which binds and stabilizes to the TTR tetramers similar to tafamidis.
What we know is that we generally shy away from any medications in this class in our patients that have significant heart failure. This has been somewhat controversial, and that's because of the potential adverse effects with NSAIDs, for patients with heart failure and others, which include GI bleeding, renal dysfunction, worsening fluid retention, and hypertension. We're still trying to understand the role of that diflunisal can play in our patients' lives. What we see is that there are these patients who are Class III/IV who potentially cannot either get on a tafamidis or who progress despite tafamidis or who just don't benefit because they're already too sick. Just to review, the Class III and IV patients are the ones that are most significantly affected.
They have a marked limitation of physical activity or cannot do normal physical activity and have symptoms even at rest. Certainly we have other things to offer patients who have significantly advanced heart failure, and this is a big part of my career, is trying to offer these other patients with heart failure, options. However, none of those options, unfortunately, really apply to the amyloid population. We have things like BaroStim, we have cardiac modulation therapy, we have Entresto, we have vericiguat, we have omecamtiv. All of which look very promising as therapies for advanced heart failure. None of which have been studied in amyloid, and none of which are available to any of these patients or have a sense that they would help, that they would help the underlying disease or help symptoms in any of our patients. We're stuck.
Similarly, for patients who don't have amyloid, we can offer things like LVAD therapy. Again, LVADs are generally not helpful in our amyloid patients because what we see is that the LV cavity is very small, and that by introducing an LVAD where we're actually removing and pulling blood out of the LV cavity, we're actually worsening the patient's symptoms. There are a select group of patients who, with amyloid cardiomyopathy, can actually have enough LV dilation to potentially withstand an LVAD, but certainly, this is not a therapy we can count on and not something that we are commonly offering by any means to our amyloid population. Transplant. The Class III/IV patients with normal heart failure that we're often able to offer for transplant were in a tough situation. A good portion of our amyloid patients that at the.
are at the time of diagnosis have already aged out and are, we're unable to offer this therapy. Similarly, when we talk about other manifestations of amyloid such as autonomic dysfunction and the neuropathy, those patients often we can't offer transplant to when they have multi-systemic disease. We know that there's this unmet need where these patients with ATTR cardiomyopathy cannot get the therapies they need to potentially make them live longer. Certainly there is the issue of quality of life. A lot of these patients, despite therapy, continue to have shortness of breath, leg swelling, fatigue, and develop cachexia.
They have conduction disorders and arrhythmias and a ton of atrial fibrillation, which leads to ablations, therapies, all sorts of things, WATCHMAN devices and things like that, which we don't have any current treatment for the underlying disease that we know would prevent atrial fibrillation or any of those symptoms. For our patients that have wild-type cardiomyopathy that may have a component of neuropathy as well, we have nothing to offer. Patients can often develop even large fiber neuropathy, which can lead to wheelchair or bed confinement. Certainly the autonomic dysfunction, arrhythmias, orthostatic hypotension, gastrointestinal, genital, and urinary disturbances. These type of symptoms are constantly plaguing our patients, and we have no targeted therapy for a lot of our wild-type cardiomyopathy patients or hereditary patients that don't have polyneuropathy. Let's go back to this patient.
He was unable to get tafamidis therapy again, because of cost and access issues. He had a progression in his symptoms and actually had trouble making it through his daughter's wedding. He's now been on diflunisal therapy for six months, but has shown significant progression in his symptoms. He sends me messages frequently, honestly, on almost a daily basis, asking about the availability of new drugs that could potentially help him feel better. We really continue to need more options to help improve the quality of life and availability of medications to this group of patients. Thank you. Back to Dr. Vest.
Thank you, Dr. Sarswat. That really was a fantastic overview, which really highlights the remaining unmet clinical need and the overarching need for additional treatment options for this patient population. With that context, I will now turn back to further discuss our ongoing studies in ATTR amyloidosis with cardiomyopathy, starting with APOLLO-B. By way of reminder, the APOLLO-B study of patisiran enrolled 360 patients with ATTR amyloidosis, either wild type or hereditary, with cardiomyopathy and symptomatic heart failure. Patients were randomized one-to-one to patisiran or placebo. The study was designed to demonstrate the impact of patisiran on functional status, with the primary endpoint in the change from baseline in 6 minute walk test at 12 months, and health status and quality of life, with the first secondary endpoint being the Kansas City Cardiomyopathy Questionnaire. These are both recognized measures of clinical benefit and heart failure.
In the context of the existing unmet need, we identified these as endpoints that could allow us to bring patisiran and the potential benefits of this therapy to this patient population as swiftly as possible. While the study was not designed to demonstrate a treatment effect on outcomes of death and hospitalization, these were also included as secondary endpoints. The study also included a robust package of important exploratory endpoints, such as cardiac biomarkers and cardiac imaging. We were absolutely thrilled to announce in scientific meetings several months ago the positive results of this study, and we are further pleased to announce last week that we have now submitted a supplemental application to the FDA for patisiran as a potential treatment of the cardiomyopathy of ATTR amyloidosis. Here we are looking at the baseline demographics between the 2 treatment arms.
The study enrolled patients who are representative of the worldwide population of patients with ATTR amyloidosis with cardiomyopathy, including a broad spectrum of disease severity and a wide range of TTR genotypes and other disease manifestations. The treatment arms were well balanced, and disease characteristics on the 2 arms were largely overlapping and overall were clinically comparable at the start of the double-blind period, thus supporting the effectiveness of randomization and the validity of comparisons between the treatment groups. Characteristics were also consistent between patients receiving tafamidis at baseline and those patients not receiving tafamidis at baseline. Consistent with the known pharmacodynamic profile of patisiran resulted in rapid and sustained reduction of the disease-causing transthyretin protein with a mean reduction of 86.8%.
It should be noted that in data not shown here but previously shared at the HFSA meeting, a comparable serum TTR reduction with patisiran was observed irrespective of baseline tafamidis treatment. Patisiran met the primary endpoint of the study, demonstrating statistically and clinically significant benefit in functional capacity assessed by the six-minute walk test compared to placebo at 12 months. As expected, based on the recognized natural history of ATTR amyloidosis, patients in the placebo group showed a steady decline in functional capacity with a median change from baseline in 6 minute walk test distance at month 12 of -21.35 meters. In contrast, a much smaller decline of -8.15 meters was observed in the patisiran group.
This observed change from baseline in the patisiran group over 12 months is comparable to the age-related decline expected in healthy adults of approximately 5 to 6 meters per year, thus indicating relative stability of disease progression in patisiran-treated patients. The study also met the first secondary endpoint, which was the Kansas City Cardiomyopathy Questionnaire overall summary score, which is an important measure of health status and quality of life. A pattern similar to that observed with the six-minute walk test was observed for the KCCQ. Over the double-blind period, patients in the placebo group showed a steady decline in KCCQ with a mean change from baseline of -3.396 points.
In contrast, an improvement of 0.478 points was observed in the patisiran group, indicating relative stability in health status and quality of life over 12 months in patisiran-treated patients. Thus, a clinically meaningful and statistically significant change in KCCQ at month 12 was demonstrated with patisiran compared to placebo. With an LS mean difference of 3.7 points and a P value of 0.0397. The treatment benefit was consistent across all KCCQ-OS domains, which include physical limitations, total symptoms, quality of life, and social limitation, as well as nearly all the questions within each of these domains.
These results provide important insights into how placebo-treated patients manifested ongoing disease progression and how patisiran-treated patients experienced preservation of health and quality of life over the 12 months of treatment. This study was not powered to show a treatment difference in composite endpoints that assess morbidity and mortality for the 12-month double-blind period, the study did not achieve statistical significance for outcomes. However, certain favorable trends were observed. Specifically, the stratified win ratio of 1.27 for patisiran versus placebo, with a p-value of 0.057 for the composite endpoint of all-cause mortality, frequency of CV events, and change from baseline in the six-minute walk test at month 12 suggests a trend toward benefit of patisiran compared to placebo. Additionally, as shown on this slide, a pre-specified analysis of all-cause mortality during the double-blind period numerically favored patisiran.
In the overall population, all-cause deaths were observed in 10, or 5.6%, of placebo-treated patients, compared to 4, or 2.2%, of patisiran-treated patients. As specified in the statistical analysis plan, this analysis treated heart transplants as deaths and did not include death due to COVID-19. Consistent results were observed in both patients on baseline tafamidis and in patients not on baseline tafamidis. Here we are showing the exploratory results for the cardiac biomarkers NT-proBNP and troponin I, which reflect cardiac stress and heart failure severity in myocardial damage respectively. These are clinically important biomarkers that are routinely monitored in clinical practice and are incorporated in recognized ATTR amyloidosis disease staging systems and an expert consensus for defining disease progression. Furthermore, NT-proBNP levels, an increase in levels, are recognized as prognostic of outcomes in ATTR amyloidosis.
Over the double-blind period, the placebo group showed a steady increase or worsening in the levels of both of these biomarkers. Of note, the substantial rise in these biomarkers in the placebo arm by month 12 was in line with published expert consensus criteria by Garcia-Pavia et al. for disease progression, i.e., a 30% increase in either NT-proBNP or troponin I. In marked contrast, the patisiran group demonstrated relative stability, resulting in a nominally statistically significant beneficial treatment effect for both biomarkers at month 12. As alluded to on the previous slide, these biomarkers, along with ATTR disease stage, which is based on NT-proBNP and eGFR, have been incorporated into published expert consensus criteria for defining disease progression.
Based on these published criteria, a post-hoc exploratory analysis was done on APOLLO-B biomarker data to determine the proportion of patients who did not meet criteria for disease progression. As shown in the left-hand column, the criteria for NT-proBNP, troponin I, and ATTR disease stage indicating no progression were an NT-proBNP change of less than 30% or change of less than 300 nanograms per liter, troponin I change of less than 30%, and no increase in ATTR disease stage. As shown in the forest plot, compared to placebo, patisiran patients were significantly less likely to experience disease progression based on the composite of these 3 criteria or by any of the individual criteria. Indeed, patisiran patients were approximately twice as likely as placebo patients to not experience disease progressions.
We believe these data underscore the relevance of the demonstrated treatment effect of patisiran on cardiac biomarkers and further support the primary results of the study. It is also notable that in a separate analysis of change over time in NYHA class, worsening occurred more frequently in the placebo group, 24.1%, versus the patisiran group, at 13.6% at month 12. Of further note, patisiran treatment also resulted in a benefit or trend towards benefit in change from baseline of most echocardiographic parameters reflective of cardiac structure and function compared with placebo at month 12. Of particular note were the nominally significant beneficial effects compared to placebo in global longitudinal strain, which is reflective of systolic function, and in LV mass. LV mass increased in the placebo arm, which is potentially consistent with ongoing amyloid deposition.
The magnitude of the increase is similar to that reported in a recent natural history study, Odaka et al. We were also very excited about the exploratory results from a planned cohort of patients with technetium scintigraphy imaging, which is a non-invasive assessment of cardiac amyloid involvement. An analysis of technetium scintigraphy, Perugini grading, is a visual assessment of technetium uptake in the myocardium compared to bones, which is widely used to make the diagnosis of ATTR amyloidosis. In 100% of evaluable scintigraphy patients in the patisiran arm, Perugini grade was reduced or demonstrated no change from baseline at month 12, with 37.8% of patients in the patisiran arm demonstrating a reduction from baseline of greater than or equal to 1 Perugini grade. Including 3 patients who reduced by greater than or equal to 2 Perugini grades at month 12.
No patient in the patisiran arm increased from baseline in Perugini grade at month 12. In contrast, among evaluable patients in the placebo arm, no patients had a Perugini grade that was reduced from baseline at month 12. Importantly, in the double blind period of APOLLO-B, patisiran demonstrated an acceptable safety profile that is consistent with the known profile of patisiran from other studies and post-marketing experience. AEs were mostly mild or moderate. AEs observed more commonly in the patisiran arm included infusion related reactions, arthralgia, and muscle spasms. SAEs, severe AEs, and AEs leading to discontinuation were balanced between the treatment arms. It should specifically be noted that there were no cardiac safety concerns, and indeed, patisiran demonstrated fewer events within standardized MedDRA queries exploring potential cardiac safety issues, including cardiac arrhythmias and cardiac failure, compared to placebo.
As you can see, in summary, we're very pleased with the totality of the data coming out of APOLLO- B. We feel the study validated the therapeutic hypothesis that RNAi therapeutics targeting transthyretin, like patisiran, have the potential to positively impact measures of ATTR amyloidosis with cardiomyopathy. We feel the results show a favorable benefit risk profile across multiple clinically important measures, including functional capacity, quality of life, biomarkers, and imaging assessments. The APOLLO- B study demonstrated the potential benefit of patisiran treatment in patients with the cardiomyopathy of ATTR amyloidosis, and it did so in just 12 months. Most of you are likely aware, in parallel with the APOLLO- B study of patisiran, our Phase 3 cardiac outcome study with patisiran, HELIOS-B, is ongoing. The study, which was designed to enroll approximately 600 patients, is a randomized placebo-controlled trial.
Like APOLLO-B, all patients have confirmed hereditary or wild type ATTR amyloidosis with cardiomyopathy at baseline and symptomatic heart failure. Patients are randomized 1 to 1 to patisiran 25 milligrams quarterly or placebo. The primary endpoint is a composite of mortality and cardiovascular events, to be analyzed when the final patient completes month 30. There is also a robust package of secondary endpoints that will allow us to fully elucidate the treatment effect. Enrollment in HELIOS-B was completed in August of 2021, much earlier than originally expected, and we anticipate top-line results from the 30-month endpoint in early 2024. We recently announced that we would not be proceeding with the optional interim analysis in the HELIOS-B study, given the relatively short timeline to the full study readout.
Allowing the study to run to completion will help us to generate the strongest possible data package and position patisiran to be a highly compelling and differentiated product among other treatments in this space. We'll now shift gears to touch on our plans to continue advancing innovation with ALN-TTRsc04. ALN-TTRsc04 is the newest addition to our TTR amyloidosis franchise. This new investigational siRNA targeting transthyretin was generated using our IKARIA platform. Preclinical development suggests exquisite specificity for the intended target in non-human primate studies, which have demonstrated remarkable potency. Collectively, we believe the profile of TTRsc04 could support an annual dosing regimen with greater than 90% serum transthyretin reduction.
In advancing the IKARIA platform, we're very excited about plans to rapidly develop ALN-TTRsc04 in order to continue our commitment to innovation in the treatment of ATTR amyloidosis, with the potential for an annual subcutaneous dosing regimen with potent and reversible effects. Importantly, there are no third-party royalty obligations associated with this program. We also anticipate patent protection extending beyond 2040. As we think about the path forward for TTRsc04, we would note our demonstrated track record for rapidly advancing innovation in ATTR amyloidosis, such as advancing patisiran from first-in-human readout to positive Phase 3 results in HELIOS-A in approximately 3 years. We are preparing for an initial Phase 1 study of TTRsc04 in healthy volunteers, which we plan to initiate at or around year-end of 2022. Phase 1 top-line data would then be anticipated in late 2023.
2022 was a landmark year for our TTR franchise, with the approval of AMVUTTRA in major markets around the world for the treatment of hereditary ATTR amyloidosis with polyneuropathy, and the readout of APOLLO-B in ATTR amyloidosis with cardiomyopathy. With that said, there are numerous significant and impactful goals and milestones ahead for the TTR franchise, including initiation of a Phase 1 study of ALN-TTRsc04 at or around year end of 2022. With the readout of the patisiran biannual dosing data now expected in early 2023. We also have the goal of submission of a supplemental New Drug Application for patisiran biannual dosing regimen in early 2023. The goal of achieving patisiran approval from the U.S. Food and Drug Administration in late 2023 for the treatment of the cardiomyopathy of ATTR amyloidosis. Continuing global launches of AMVUTTRA in hereditary ATTR amyloidosis with polyneuropathy.
Reporting top line ALN-TTRsc04 Phase 1 study results in late 2023. Importantly, rigorous execution of the ongoing HELIOS-B Phase 3 study with top-line data in early 2024. We could not be more excited about the accomplishments to date. We look forward with great anticipation to bringing further innovative therapies to patients in the years to come. With that, I thank you for your attention and would like to hand the presentation over to Dion Zappe, who will review the latest progress with our, with our zilebesiran program. Dion?
Thank you, John. Hello, I'm Dion Zappe, Executive Director, Clinical Development at Alnylam. I lead the clinical research team in the development of zilebesiran, an investigational and innovative RNA interference therapeutic for the treatment of hypertension. I'm very excited today to give you an overview of our ongoing Phase 2 program with our 2 KARDIA studies focusing on the management of hypertension. As you'll hear in this presentation, we believe zilebesiran has the potential to drastically change the way hypertension is currently managed by addressing one of the biggest challenges with current treatments, inconsistent and ineffective blood pressure lowering, primarily due to medication non-adherence. It is well-recognized that hypertension is a highly prevalent disease with over 200 million people with primary hypertension in just the 7 major markets. Hypertension poses substantial risk for cardiovascular morbidity and mortality if not effectively treated.
Despite the widespread availability of treatments to manage the disease, more than 70% of hypertensive patients are not at their target blood pressure goal. Factors for poor control of hypertension include lack of intensification of therapy and poor adherence to treatment. With both which both contribute to the low blood pressure control rates, and as a result, a heightened risk for cardiovascular disease. Despite the widespread availability of numerous oral antihypertensives across a number of different drug classes, these once-a-day therapies cannot adequately address the unmet need of medication non-adherence in hypertension. Indeed, improving the management of hypertension includes more than blood pressure lowering. It is done with the hope of further reducing cardiovascular risk and end organ damage.
To do this, you need to achieve a magnitude of blood pressure reduction to reach a target blood pressure, which is the quantity of blood pressure control, but you also need to reduce blood pressure consistently throughout the 24-hour period, including nighttime blood pressure and over the long term, that is blood pressure variability, and we call this the quality of blood pressure control. Tonic blood pressure control should then include a treatment that targets not only the quantity of blood pressure lowering, but also the quality of blood pressure lowering to reduce blood pressure variability over time and within the 24-hour period to address the key unmet need in hypertension management. We believe zilebesiran, a novel investigative RNAi therapeutic, can address the unmet need in hypertension.
zilebesiran is a GalNAc-conjugated small interfering RNA targeting the hepatic production of angiotensinogen or AGT, the most upstream product of the renin-angiotensin system or RAS. The RAS is one of the key regulatory systems underlying blood pressure control. In essential hypertension, it is this system which is typically dysfunctional with the renin-angiotensin system being inappropriately elevated. Silencing the messenger RNA that would encode for AGT or angiotensinogen, it's the most upstream precursor for the RAS, therefore, blocking the production of angiotensin II essentially removes the key factor needed to activate the renin-angiotensin system. It is this approach that differentiates it from oral RAS blockers. These drugs suffer from poor adherence and the possibility of RAS escape, limiting their efficacy. In clinical trials, zilebesiran is being dosed infrequently via subcutaneous injection with prolonged duration of pharmacologic action.
This durability of effect could potentially provide both improved medication adherence and consistent, durable blood pressure control. The clinical development of zilebesiran began over three years ago. This began with our Phase 1 study, a multi-center trial designed to evaluate safety tolerability, the pharmacokinetic/pharmacodynamic effects of subcutaneous administration of zilebesiran in patients with mild to moderate hypertension. The study was conducted in 4 parts. Today, I'll review results from these various parts. We believe these provide the initial indication of zilebesiran's clinical profile and its potential to address the unmet need in hypertension. It's worth noting that some results from parts 1, 3, and 4 included in this presentation have been previously presented. Results from Part 2 are being presented today for the first time, as well as some biomarker data from Part 1.
Let me now review results from Part 1, a randomized placebo-controlled single ascending dose study aimed at establishing single-dose proof of concept. In Part 1, treated or untreated hypertensive patients received either a single dose of zilebesiran across the 7 doses with 8 patients per cohort or placebo with 4 patients per cohort. This study was conducted in an outpatient setting, allowing patients' usual daily activity and dietary sodium intake. The study evaluated the safety and efficacy of zilebesiran after a single dose, specifically to assess its long-term effects on angiotensinogen, blood pressure, safety, and as mentioned, to establish the single-dose proof of concept. The dose-ranging study with zilebesiran confirmed what we had anticipated, a dose-dependent effect with target engagement clearly achieved.
zilebesiran administration demonstrated a reduction of greater than 90% in serum angiotensinogen from baseline with single doses of zilebesiran from 100-800 milligrams from week 3 and sustained up to 12 weeks. All patients who received a single dose of zilebesiran 800 milligrams maintained greater than 90% reduction in serum angiotensinogen levels through week 24 or 6 months. This effective and sustained inhibition of angiotensinogen is critical to zilebesiran's ability to chronically inhibit the renin-angiotensin system and its proposed durability of effect, something standard oral RAS blockers have never been able to achieve. Thinking in more detail about the mechanism of action of zilebesiran in comparison to standard oral RAS blockers and their effects on the renin-angiotensin-aldosterone system cascade, you will see some important differences.
If you look at current agents on the market, such as angiotensin receptor blockers, they act on downstream mediators of the RAS, specifically angiotensin II receptors or AT1 receptors to lower blood pressure. By acting on downstream mediators, there are counterregulatory rises in renin and also increases in angiotensin II, as depicted here with the ARBs. Increases in renin associated with ARB treatment lead to increases in angiotensin II levels higher than pretreatment, which can overcome blockade of the angiotensin receptor, causing loss of blood pressure-lowering effect. This is further compounded by the requirement of oral therapies to be dosed daily, leading to medication adherence concerns, which can lead to variable blood pressure lowering. The possibility for escape from the effects of current oral RAS blockade can result in a modest blood pressure-lowering response.
It is evident then, in our view, that there are a number of potential mechanistic disadvantages with angiotensin receptor blockers and broader oral RAS blockers. Short duration of action, which facilitates variable blood pressure reductions and the potential for incomplete RAS inhibition. Daily dose administration, which carries the potential for low treatment adherence, and this RAS escape phenomenon with subsequent loss of antihypertensive response. To potentially avoid these disadvantages and get optimal blood pressure control, we believe it may be more effective to dampen the whole renin-angiotensin-aldosterone system pathway by acting further upstream, that is, by silencing liver-derived angiotensinogen. Angiotensinogen is the primary substrate and the sole precursor of all angiotensin peptides, including the generation of angiotensin II. By silencing angiotensinogen, you can effectively shut down the involvement of the RAS in hypertension. What effect does the zilebesiran have on the renin-angiotensin-aldosterone system?
The increase in renin depicted here with zilebesiran treatment is caused by the silencing of AGT, which is renin substrate. This increase in renin is not expected to lead to RAS escape as the silencing of AGT works to deplete levels of angiotensin II, whereas angiotensin II levels increase with ARBs, and in some cases high enough to even overcome the receptor blockade. In summary, our RNAi approach with zilebesiran potentially confers a number of mechanistic advantages, including liver-specific AGT silencing, prolonged duration of action, consistent and durable blood pressure response, infrequent dose administration, that is, injection every three or six months, and thus the potential for improved adherence with more effective RAS inhibition, potentially avoiding the escape phenomenon associated with oral RAS blockers. How does zilebesiran affect the RAS biomarkers?
If we are right with this new data, which has never been previously presented, we should see a differential effect of zilebesiran on the RAS biomarkers. On the left-hand side, the graph shows increases in plasma renin. Now, as mentioned before, a dose-related rise in plasma renin is a response to the effectiveness of the angiotensinogen silencing. This is indeed what we saw in Part 1 of our Phase 1 study, sustained increases in plasma renin at weeks 12 and 24. These increases in plasma renin concentration were associated with a reduction in angiotensin II and aldosterone, as shown on the graph on the right-hand side. The changes in the RAS biomarkers associated with angiotensinogen silencing demonstrate the potential ability of zilebesiran to affect more complete inhibition of the renin-angiotensin system and thus avoid the RAS escape, which is associated with oral RAS blockers.
With this kind of control on the RAS cascade, one would expect excellent quantitative and qualitative effects on blood pressure control, and this is what we saw with the single-dose effects of zilebesiran. As shown on the left graph, the reduction in systolic blood pressure with zilebesiran-treated patients was consistent and stable at all time points over the entire 24 hours at week 6, with clear effect at both daytime and nighttime blood pressure. Although the data is not shown here, the reductions in daytime and nighttime systolic blood pressure were sustained even to later time points, weeks 12 and 24. Thus, a single dose of zilebesiran demonstrated effective blood pressure control throughout the 24-hour period, highlighting its persistent effect on the quality of the blood pressure lowering. The graph on the right demonstrates the sustained effect of zilebesiran on the quantity of blood pressure lowering.
That is, reductions in mean 24-hour systolic blood pressure of greater than 10 millimeters of mercury were achieved at week 12 across three dose groups of zilebesiran, 200, 400, and 800 milligrams, with clinically meaningful reductions in blood pressure being maintained out to week 24. Most interesting, after a single dose of zilebesiran, 800 milligrams, a mean 24-hour systolic blood pressure reduction of greater than 20 millimeters of mercury was observed at week 24. It's also important to note that 6 out of the 8 patients in this group achieved this reduction in systolic blood pressure, greater than 20 millimeters of mercury, at week 24 without the use of add-on antihypertensives.
In summary, for Part 1, effective RAS inhibition with zilebesiran translated into qualitative and quantitative aspects of blood pressure control by resulting in 24-hour blood pressure lowering, which was sustained with a single dose out to 6 months of treatment. Moving on to Part 2, our Phase 1 study, we conducted a proof-of-concept study to test multiple doses of zilebesiran in obese hypertensive patients. Data from this part of the study have not been previously presented. In Part 2, which was a cohort of 12 obese hypertensive patients, they were randomized 2 to 1 to receive zilebesiran at 800 mg at baseline and at day 85 or week 12. They received the ARB irbesartan at 150 mg a day, which is the standard antihypertensive dose.
The study evaluated the effects of multiple dosing of 800 mg of zilebesiran in obese patients every 85 days or at 3 months in a head-to-head comparison with 150 mg of irbesartan daily. The change from baseline blood pressure was measured by 24-hour ambulatory blood pressure monitoring, and this occurred at week 6, 8, 12 and out to 24 weeks. Other evaluations looked at the impact of zilebesiran on body weight, body composition, and metabolic parameters by testing the hypothesis that changes in angiotensinogen levels may drive some metabolic effects. As you saw the exciting effects of single-dose zilebesiran on blood pressure lowering, we were very eager to investigate the level of blood pressure reduction with multiple doses of zilebesiran.
We observed reductions in mean 24-hour systolic blood pressure for zilebesiran 800 milligrams at weeks 8, 12, and 24, and we observed reductions of up to 27 millimeters of mercury in systolic blood pressure in comparison to the blood pressure lowering observed in patients undergoing treatment with the ARB irbesartan. As we investigated this in Part 2, we were delighted to find that, if anything, the blood pressure lowering effect was maintained but also quantitatively it looked better in this small sample size and also numerically different from the standard of care ARB irbesartan. We did not, however, observe any changes in body weight, body composition, or changes in metabolic parameters with zilebesiran after 24 weeks of treatment.
As we discussed earlier, the biomarker data observed with zilebesiran was consistent, and it is quite contrasted with the oral ARB irbesartan, where you see the signs of renin activation driving increases in angiotensin II to overcome the receptor blockade. Looking at the bar chart on this slide, we observed consistent increases in plasma renin and reductions in angiotensin II and aldosterone out to 24 weeks in response to 800 milligrams of zilebesiran. For irbesartan, we saw increases in plasma renin concentration, but also saw increases in angiotensin II and aldosterone, quite different than what you get with effective angiotensinogen inhibition. These biomarker results with multiple doses of zilebesiran are similar to Part 1 of the single-dose data and provide preliminary evidence that supports the potential for zilebesiran to lead to effective and sustained RAS inhibition, thus avoiding RAS escape.
Moving on to Part 3 of our Phase 1 study, which was designed with a focus on evaluating the safety of zilebesiran. Specifically, the study was designed to observe the effects of salt restriction with an aim to inform the safety and tolerability of volume depletion in response to zilebesiran treatment. In order to assess the safety effects during a 2-week period of controlled salt intake, a single subcutaneous injection of zilebesiran at a maximum dose of 800 milligrams was evaluated. A cohort of 12 patients were randomized 2 to 1 to receive zilebesiran 800 milligrams or placebo. Changes in 24-hour systolic blood pressure in response to a low salt diet, followed by a high salt diet, were measured before and after zilebesiran dosing over 2-week periods. How did salt affect the blood pressure response?
The first part of the study was a control to observe changes in blood pressure in response to a low salt diet followed by a high salt period. As expected, there was an average reduction of 9 millimeters of mercury in 24-hour systolic blood pressure at day minus 15 following a low salt diet. Blood pressure increased back to baseline at day minus 8 upon switching to a high salt diet in all patients. Thus, in this study, the hypertensive patients demonstrated a sensitivity to the effects of salt on blood pressure. Approximately 6 weeks after a single injection of zilebesiran, the blood pressure response to the same low salt diet followed by a high salt period were observed. In patients given zilebesiran, the change in 24-hour systolic blood pressure were much more profound following a low salt diet.
For patients receiving zilebesiran, there was an approximately 19 millimeters of mercury reduction in systolic blood pressure compared to placebo, which saw a reduction of 10 millimeters of mercury. A high salt diet attenuated the blood pressure lowering effect of zilebesiran with values returning to baseline levels. These data demonstrated that variations in salt intake can influence the blood pressure lowering response to zilebesiran. From a safety perspective, there were no serious adverse events or adverse events in Part 3 leading to study withdrawal, and no patients required intervention for low blood pressure, including during the low salt diet. No clinically significant elevations in liver enzymes, serum creatinine, or serum potassium were reported in the zilebesiran group. These data demonstrate that something as simple as a high salt diet may be sufficient to reduce the blood pressure lowering effect of zilebesiran.
The clinical significance of these findings could be in instances in which we'd want to modify the antihypertensive response to zilebesiran. These data indicate that using standard measures such as increasing salt and water intake could potentially limit the antihypertensive response. As discussed, because of these effects in the rare or uncommon cases where you may want to cease or reverse the antihypertensive effect, such as if a patient is hemodynamically unstable, current conventional means, in theory, could be adequate. In order to further explore the capabilities of the Alnylam RNAi platform, we have developed the REVERSIR technology that could reverse the effect of a treatment like zilebesiran. This topic will be addressed later today by my colleague, Vasant. Turning to Part 4, the last part of our Phase 1 study.
We were interested in exploring the safety, tolerability, and additivity of adding the RAS blocker irbesartan at its maximum antihypertensive dose of 300 milligrams to zilebesiran. This type of therapeutic regimen, that is, combining 2 RAS agents, is currently discouraged when managing hypertension. In this Phase 1 study, we wanted to see the safety effects of adding the ARB irbesartan to zilebesiran, a novel antihypertensive that also affects the RAS, but in a unique way. In Part 4, 16 hypertensive patients received open label treatment with zilebesiran 800 milligrams subcutaneous on day 1. After 6 weeks of zilebesiran treatment, patients whose mean 24-hour systolic blood pressure remained at or above 120 millimeters of mercury proceeded to receive irbesartan. There were 10 patients who did this.
While those whose mean 24-hour systolic blood pressure was less than 120 millimeters of mercury remained on zilebesiran only, and there were 6 patients in this group. In those patients who remained on zilebesiran only, they had large reductions in systolic blood pressure, approximately 22 millimeters of mercury at week 6 or day 41. This was maintained through to at least day 56 or week 8. In those patients who received add-on irbesartan of 300 milligrams a day for the next 2 weeks, that is from day 43 to day 57, they experienced roughly an additional 6 millimeter mercury reduction in systolic blood pressure on top of the approximate 8 millimeters of mercury delivered by zilebesiran through day 41 or week 6. Encouragingly, there were additional blood pressure reductions, but it was not associated with any significant elevations in serum creatinine or potassium.
Additionally, there were no serious adverse events or adverse events of hypotension or low blood pressure that required intervention. Since our Phase 1 study was also focused on evaluating the tolerability and safety effects of zilebesiran in hypertensive patients, it's important to summarize our findings from these 4 parts of our Phase 1 program. In Part 1, single-dose zilebesiran was well-tolerated, and there were no treatment-related serious adverse events. All adverse events were mild or moderate in severity, and they resolved without intervention. No patients required intervention for low blood pressure, and there were no cases of elevations in liver enzymes, serum creatinine, or potassium during the study. In Part 2, multiple doses of zilebesiran at the maximum dose of 800 milligrams were generally well-tolerated, and there were no treatment-related serious adverse events. All adverse events were mild or moderate in severity and resolved without intervention.
No patient required intervention for low blood pressure. There were no elevations in liver enzymes, serum creatinine, or potassium during this study. In Part 3, in response to salt restrictions, zilebesiran was well-tolerated with no treatment-related serious adverse events, and there were no patients who required intervention for low blood pressure. In Part 4, the addition of irbesartan to zilebesiran was generally well-tolerated and led to further reductions in systolic blood pressure with no adverse events of concern for hypotensive events, and there were no clinically significant changes in serum creatinine or potassium, and there were no treatment-related serious adverse events. Overall, these data from our Phase 1 study provide initial indication of zilebesiran's potential clinical profile.
That is, angiotensinogen inhibition leads to more effective inhibition of the renin-angiotensin system, as demonstrated by improvements on the quality and quantity of blood pressure lowering with effective 24-hour blood pressure control that's sustained out to 6 months of treatment. These findings support continued development of zilebesiran and leads us to our Phase 2 KARDIA program. We initiated a Phase 2 clinical program in 2021 to further interrogate zilebesiran and its potential profile in hypertension. This clinical program includes 2 studies. KARDIA-1, a monotherapy Phase 2 study in 375 hypertensive patients designed to evaluate the efficacy and safety of zilebesiran as a monotherapy in patients with mild to moderate hypertension. This trial is exploring both quarterly and biannual dosing regimens.
Our second Phase 2 study is KARDIA-2, which is a combination study in 630 patients that's designed to evaluate the efficacy and safety of zilebesiran as concomitant therapy in hypertensive patients whose blood pressure is uncontrolled despite receiving standard antihypertensive therapy. More specifically, KARDIA-1 is a double-blind placebo study to evaluate the effects of zilebesiran in patients with mild to moderate hypertension. The study is designed to identify the dose or doses of zilebesiran to take into Phase 3 by evaluating the effectiveness at 3 and 6 months using quarterly and biannual dosing. The study was initiated in mid 2021. We are very pleased to announce that enrollment in KARDIA-1 is now expected to be completed at or around year-end 2022, earlier than previously expected, with top-line results in mid 2023.
KARDIA-2 is our double-blind placebo-controlled study in patients with blood pressure not adequately controlled on standard of care antihypertensive therapies. This study is focused on evaluating the efficacy and safety of zilebesiran 600 mg at its max dose when added to each of the 3 most common classes of antihypertensives. The angiotensin receptor blocker olmesartan, the calcium channel blocker amlodipine, and the diuretic indapamide in patients despite receiving one of these therapies, but whose blood pressure is still uncontrolled. The primary endpoint of the study is to evaluate zilebesiran after 3 months of therapy on the additive blood pressure-lowering effects. Additional secondary endpoints will evaluate the 6-month effects of zilebesiran and whether blood pressure was controlled without the need for add-on antihypertensive therapy. The study will also assess the safety and tolerability of zilebesiran as additive therapy to standard of care antihypertensives.
The study will enroll 630 patients that randomized to zilebesiran or placebo who remain hypertensive after completing 4-week run-in on protocol-specified background antihypertensive medication. Enrollment completion is now expected to be in early 2023, with top-line results expected by or at year-end 2023. In summary, there continues to be significant unmet need for the treatment of hypertension in patients with uncontrolled blood pressure. We think this can potentially be addressed by zilebesiran. Data from our phase 1 study support the therapeutic hypothesis that zilebesiran may allow for patients to achieve tonic blood pressure control. That is durable 24-hour blood pressure control, sustained blood pressure lowering throughout the day and nighttime, and this happens day after day for up to 6 months.
We also have some new exciting data that highlights the persistent effect of zilebesiran to inhibit angiotensinogen and decrease vasoactive RAS biomarkers through week 24, suggesting more complete RAS inhibition in contrast to oral RAS blockers. Accordingly, we believe zilebesiran has potential to become a new class of antihypertensive treatment for patients with a history of poorly controlled hypertension. We are currently testing the further blood pressure-lowering efficacy of zilebesiran in our KARDIA Phase 2 program as we have 2 ongoing studies, and we're excited about how these 2 trials are progressing with top-line results expected in mid 2023 for KARDIA-1 and year-end 2023 for KARDIA-2. This concludes my presentation today. As you can see, we have a lot to look forward to with the zilebesiran hypertension program in 2023. Thank you for your time and attention.
We'll now move on to our first question-and-answer session of the day.
Be here with all of you. There we go. Looks like it just came up. All right. Good morning, everybody. My name is Pushkal Garg. I'm the Chief Medical Officer at Alnylam, and it's great to see you. Thanks, Dion, for your presentation, and Dr. Nitasha Sarswat and John Vest. We've got a great panel, and we wanted to now get into some questions. We've got a great attendance at R&D Day today, and a lot of questions have come in. Maybe just more formally, I wanna welcome Dr. Nitasha Sarswat from the University of Chicago. Rena N. Denoncourt is our Vice President and TTR Franchise Lead. We have John Vest, who is the overall TTR Clinical Franchise Lead, and Dion Zappe, who's the Clinical Lead for our zilebesiran program in hypertension.
I'm just gonna start going through some of the questions that have come in. Maybe I'll first start, John, with you. There have been a number of questions and comments just congratulating on the submission of the APOLLO-B sNDA application, and questions about what are the next steps. When will we hear back about whether the file has been accepted, and will this be a standard or priority review? What's the course for that application?
Yeah. Thanks so much, Pushkal, and thanks for the question. We're absolutely thrilled to have announced that we submitted the file to the FDA. Typically, we would expect to hear back from the FDA within 60 to 74 days with regard to the application. We would expect that this will be a standard review, which would then mean we would expect an approval late next year, in late 2023, of course, pending the FDA's review and decision on the file.
Fantastic. That's really helpful. We've also gotten some questions, John, about whether there would be an ad com for this application. Anything you can comment on that?
Look, the question with regard to ad com, that's always gonna be at the discretion of the FDA. I don't think there's anything further that we can comment on there. That will be a decision for the FDA.
Great. Thanks. Another question that's come in is we talked early on, actually mentioned the fact that the that Regeneron has opted to not move forward with the Cemdisiran IgAN program. They've opted out of that. Wanted questions about what is the impact of that on the combination programs that are going on. You know, Regeneron is advancing programs with, in both myasthenia gravis and PNH. I can take that one, which is that there's really no impact on that at all. Those programs are still going forward. We're very excited about the potential of Cemdisiran and Pozelimab combination in those diseases and the potential to address real unmet need for patients with those. Those programs are continuing on without change.
I also wanna just reiterate that there was questions about what was the reason about their opting out. Again, for them, this was really a part portfolio prioritization decision. I really can't comment beyond that. This was not related to safety or efficacy. You know, the efficacy that we've seen has been quite compelling with about a 37% reduction in proteinuria, an encouraging safety profile. We really see an opportunity for this medicine, you know, in light of Regeneron's recent decision, we need to just take a step back and consider future options and how we'll develop this medicine going forward. We'll keep everyone posted as we have updates on that. There was a couple questions that have come in around the AMVUTTRA biannual dosing regimen.
We announced today that there's gonna be a delay in the top line results coming out of that. Really questions about how do we think about the opportunity there relative to the quarterly AMVUTTRA regimen that's already been approved. Maybe Rena, I could turn to you, can you just talk a little bit about the reasons for the delay? You know, what are we seeing so far as we talked about actually the, you know, AMVUTTRA's now starting to be launched. It's been approved in 5 territories. What are we seeing there? What are the implications and what's the thinking around the biannual regimen and the opportunity that that presents?
Sure. Sure. Let me start with the exciting AMVUTTRA progress that we've had since the commercial launch. We are very pleased with what we've seen in the, in the first few months of launch in the U.S. particularly. There have been an average of start forms that have increased significantly since what we had previously seen with ONPATTRO. In the ONPATTRO world, historically, there were about 30 start forms per month on average. Since the approval of AMVUTTRA, we're seeing that tick up to about 60 start forms per month average that we reported in Q3. Those start forms are coming from new to Alnylam patients as well as ONPATTRO switches, which I think really conveys the attractiveness of the totality of the AMVUTTRA product profile across efficacy, safety, and the mode and frequency of administration.
Q3, Q3M is off to a strong start. Now certainly, the Q6M regimen or the biannual dosing regimen, we do consider that to be a nice to have, and that's why we're evaluating it in the HELIOS-A randomized treatment extension right now, as we've discussed. We are looking forward to sharing that data with you in 2023, early 2023. Again, it was an aggressive goal to achieve by year-end 2022, so we're just around the corner with looking forward to further shed light on those results in 2023.
Fantastic. Thanks, Rena. Dr. Sarswat, some questions coming in from you. A lot of appreciation for how you sort of framed out the unmet need. Can you talk a little bit, you know, one of the things that I think people were looking to hear is, you highlighted the unmet need. In light of that unmet need and what you're seeing from the APOLLO-B data, what are your impressions? Do you, can you maybe comment a little bit about what you've seen in the data, whether you see this as a potential treatment option for patients, and what strikes you in the data?
Absolutely. You know, we talked about the unmet need largely being that there's still a good portion of patients that feel inhibited and that their quality of life is still not what they want it to be. Despite stabilizer therapy, there are still a good number of patients that either can't afford or can't get on stabilizer therapy or just continue to progress. We know from the ATTR-ACT data that there are still a good number of patients that will continue to progress. With that progression and longer life comes worsening morbidity. Certainly there is a niche here for patients to improve their quality of life. I think the APOLLO-B data is meaningful, and that 6 minute walk test, quality of life testing, was impressive.
That is something that I discuss with patients on a daily basis and run through the data. I think one of the most striking things that I've seen in the APOLLO data was also a suggestion that perhaps there's a level of myocardial regression of amyloid deposition that we see in the echo data. Certainly the biomarker data is also very impressive. I think the most striking, though, however, is really that imaging data that has even caused me to rethink how I follow a lot of these patients and what parameters we should be following going forward.
That's great. really helpful. you know, John, there are some questions because you presented some new data, in terms of clinical progression, looking at a couple of different measures. Can you just elaborate a little bit more on what was found there? and then maybe Dr. Sarswat can talk a little bit about does she use those types of, measures, in following her patients in clinical practice.
Yeah. Thanks, Pushkal. We are really excited about this data, and we're very pleased for it to begin with to see that there's starting to be a consensus and publications around what defines progression in these patients, and this link to biomarkers. When we look at this, very pleased to see that along any of the metrics that are followed, whether it's NT-proBNP, troponin, ATTR disease stage, or a composite of all of the above, that it appears that there's less progression, by these, by these, you know, increasingly accepted, now published criteria. There's a suggestion of less progression in the patisiran-treated patients compared to placebo.
For us, this really, we were very pleased about the overall biomarker data with NT-proBNP and troponin, but these additional analyses, we think, really underscore the clinical importance of those findings, and of the primary results of the study.
Great. Dr. Sarswat, can you comment a little bit, I guess maybe 2 parts. You know, how do you follow progression in patients? You said that there are some patients who are, for example, stabilizer non-responders or other patients who may be progressing with their disease. Do you use measures like BNP or troponin or disease stage or NYHA class to follow those patients?
Absolutely. That's exactly what we follow. We have a pretty set clinic algorithm where we're essentially following biomarkers on these patients, NT-proBNP and troponin, as well as eGFR, depending on which staging system you look at. We're following all of those things every 3 months on patients. We're assessing quality of life and New York Heart Association. We're not obviously doing KCCQs on every single one every 3 months, but that is a big part of what factors into the discussion that we have in clinic. Similarly, from an imaging perspective, I've always felt that cardiac MRI will offer us the best way to follow amyloid deposition.
As you guys pointed out in the APOLLO-B data, right, again, the LVEDD, the stroke volume, I think are things that we should be focusing on, whether it's by echo or MRI, should be following going forward. In addition to T1, T2, ECV on MRI, LV mass on echo. I think all of those are important parameters. Those certainly fit into our serial measurements in our algorithm. Obviously, you know, when we talk about what constitutes disease progression, there is a level of what's happening with biomarkers and imaging, but certainly there's just the patient that's sitting there in front of you telling you something's different, something's gotten worse. I can't keep up with my grandkids the way I could 6 months ago. Something's changed. That, you know, means more than anything.
Thank you. Really helpful. Looks like there's just a whole host of different measures that you can be following in these patients, and so that's great to hear. Maybe we'll turn over, Dion, to you. Some questions coming in on the hypertension program. You presented some new biomarker data on renin and Ang II and Aldo. The first questions coming in is, you know, the understanding that elevated renin levels are a potential driver of RAS escape, and I think you showed some data showing higher elevations in renin levels. Can you just comment on whether that's a cause for concern with zilebesiran?
Yes. Thank you, Pushkal. As you mentioned in my presentation, with zilebesiran, you get very effective inhibition of angiotensinogen. We know that if you can inhibit angiotensinogen to a very significant amount, and we showed with up to 800 milligrams greater than 99% reduction in angiotensinogen levels. What that does is actually changes the way the renin-angiotensin system is regulated. Rather than being a renin dependent, rate-limiting step, you actually change it so angiotensinogen becomes rate limiting. Effective reductions in angiotensinogen results in effective reductions in angiotensin II. As a result, you see increases in renin.
In contrast to oral RAS blockers, where that increase in renin is observed, particularly with angiotensin receptor blockers, and if it gets to high enough levels, it can overcome the RAS blockade, whereas that's not the case with zilebesiran. Very interesting to contrast the 2 effects.
That's really helpful. Can you comment a little bit about how common is RAS escape with conventional ACEs and ARBs? Is that a common phenomenon? Do you see patients who aren't responding to those agents? Is that, maybe you could give a little context around that?
Yes. One of the interesting things with angiotensin receptor blockers and ACE inhibitors has been that these are well-established agents in the management of hypertensive. They're effective in reducing blood pressure. There's also been a desire in the last 20 years to improve on the blood pressure lowering effect of these agents. It was always thought that more complete inhibition of the renin-angiotensin system would derive more benefits from blood pressure lowering. We've seen that that hasn't really worked in terms of showing really much additional reductions in blood pressure, but we've seen some added safety concerns.
What we're doing with zilebesiran is we're really interested in looking at this unique way or novel way of interrupting the renin-angiotensin system, and perhaps by exploring it as an add-on, as we've shown in our Phase 1 study, where we had additional reduction of blood pressure, and really further evaluating that in our Phase 2 study to see if we can see added benefits on blood pressure lowering without a safety concern. I think that will be the real test for us to see if there's added benefit with zilebesiran on top of standard oral RAS blockers.
Fantastic. That's really, really helpful. John, questions come in around this awareness that Ionis has increased the size of some of the eplontersen clinical trials in cardiomyopathy. Can you just comment on question that's come in is around HELIOS-B. How are we feeling in terms of the sizing and powering of our study? Do we feel confident about that? Are there plans to increase the size, for example, of our study?
Yeah. Thanks, Pushkal. look, we remain very confident in what we're seeing on HELIOS-B and very confident in the design, the size, and the powering of the study. We do not have any intention at this point of time to make any changes.
Great. Very, very helpful. Maybe another question for you and or Rena is just what are the plans in terms of the APOLLO-B, maybe I can turn this to you, Rena, 18-month data, in the open label extension? I guess patients are crossing over, and there's questions around will be, you know, what are the plans for putting those data out, in the, in the public domain. I guess, you know, John, maybe for you, is that something that we'll be providing to the FDA or What's the management of that in the context of the ongoing you know, review of the, of the application?
Sure. I'll start, and happy to turn it over to John. Certainly consistent with typical Alnylam practice, we do intend to bring these data forward. The 18-month data are right around the corner, and we would be mapping out what our 2023 Congress and presentation plan looks like right now and fully intend to share that with you in due time. John?
Yeah. Thanks. With regard to what we would plan to share with the FDA, what the standard practice is to provide safety data at day 120, and we will certainly be doing that.
Great. That's helpful. Dr. Sarswat, a question for you. You talked in your presentation about sort of the growing burden of heart failure, and you talked about sort of, you know, increased numbers of patients. Can you comment on, and maybe, I guess, more specifically for ATTR, are you starting to see patients being diagnosed in earlier stages of disease, and is that part of why we're seeing this growth? What are the implications of that with regard to, you know, when do you think with the available therapies we should be treating these patients, and how early?
Absolutely. I think I've seen a huge paradigm shift. I feel like I've been in the amyloid field for a little over 10 years. What a difference it has made. You know, not a single week goes by that a resident or fellow is not calling me with new cases. They are thinking about it. They're attuned to it. Everybody has a much higher index of suspicion. When you go to cardiology conferences, it's a hot topic. People are interested in the research behind this and what is happening. Absolutely there is certainly earlier diagnosis that's occurring and just more widespread diagnosis. I think that's not just at academic institutions, that's in the community as well. I think not only industry and academia, everybody has done a wonderful job really trying to hit at education, and it's made a difference.
I think it certainly makes a difference. I think, the patients that we're catching earlier and getting on treatment earlier are more likely to respond. They are the people that, after a year or 2 of treatment, are looking at me and saying, "Are you sure you got the diagnosis right? It just feels so good. Everything I read says that, you know, I'm supposed to be getting a lot worse, and I feel so good." There are definitely those, that category of patients as well. I think what we don't understand certainly is who are those non-responders and who are the responders? Are there certain clues that can give us on who will respond and who will need more therapy? We don't know that yet.
Absolutely, I do think the earlier we catch people, the more treatable, and I think our threshold for treating should be a very low one because the consequences of not doing so are potentially very disastrous for that patient.
Very helpful. Very helpful. Maybe another question for you, Dr. Sarswat, is, you know, given what you just said, and in light of what you're seeing in terms of the clinical data from APOLLO-B on ONPATTRO, the questions are coming in. You know, from your clinical experience, where do you see if, assuming it was approved, potentially using a drug like ONPATTRO for the patients that you know, when you describe the unmet need, and the range of patients that you see in your clinical practice, how might you use this or employ this in the, in the treatment of your patients? You know, where in the armamentarium?
Sure. Still, I mean, I think this is still a discussion that we have every day. That patient that I talked about in the presentation, it, there are a lot of very intelligent patients who are looking for a discussion with their physician. It's walking through the data that we have and presenting it and saying, you know, "This is what we know so far. We know that this is a changing landscape, but what we know so far is that there is potential for regression.
There is certainly a sense of improvement in quality of life and biomarkers." If things are not going in the right direction or even people that are still continuing to do well, to be able to attack the disease at a different level, knowing the downside of not potentially adding therapies, is this something that you would be willing to take on? I think as the therapies become easier and easier for patients, for instance, vutrisiran versus patisiran, right? just in their, in their lifestyle and being able to actually be able to get the drug in the convenience of their life, things will get easier and easier for the patients, and they're more likely to want to be on these drugs as well.
There are lots of patients that will, you know, just defer to us and say, "If you think this is the right thing to do, I will do it regardless of, you know, anything else." There are patients that wanna know the data, that actually will want to see APOLLO-B data, that I will show them the actual data. I will show them what I know. Everyone's different, but I think there is still that need there to have those discussions. It fits in the armamentarium, as you said, for people, wild-type patients who cannot get on any therapy, wild-type patients who are progressing or maybe even those that aren't, that just wanna be able to have another way of attacking the disease.
Hereditary patients who don't have a neuropathy or don't have other indications right now for siRNA therapy.
Super helpful. Thank you. Dion, questions come in around zilebesiran. Can you talk a little about, I guess, you know, people are asking you this long-acting, blood pressure lowering medicine, and what happens if there are hypotensive events, you know, after someone has started the therapy? I mean, maybe you could talk a little about what the clinical experience has been with regard to hypotension in the Phase 1 that you've reported out on, and then what are the plans and how, you know, how can that be addressed if someone did have a hypotensive event on zilebesiran?
Right. Perfect. Yes. In our Phase 1 study, it's important to remember here that we did not see any cases of hypotensive related episodes. It's also important to note that in our ongoing Phase 2 studies, if a patient does experience a hypotensive event, we have certain protocol in place. The first one is to reduce any background oral antihypertensive medication. That's the first strategy. It's also important to note that in our preclinical program, we demonstrated that with RNA inhibition of angiotensinogen, you can reverse the effects, the antihypertensive effects, by using standard measures, you know, such as salt loading and pressors and so forth. We also demonstrated in our Phase 1 study that in a high salt intake can also limit the antihypertensive response to zilebesiran.
We feel very confident that using standard clinical measures in clinical practice, if a patient does have experience of hypotensive events, there's certain things that can be done to limit the antihypertensive or hypotensive response to zilebesiran. There may be some clinical conditions where acutely we need to reverse the effects of zilebesiran. As I mentioned in my presentation, we are going to have later today a discussion about the development of a reversal agent for zilebesiran. Right now it's in preclinical development. We have plans to have discussions with health authorities on what would be a successful clinical development plan for this reversal agent, but we do have plans for that in place.
Thanks, Dion. Very helpful. A question came in around our, you know, the actually announced, the ALN-XDH program hadn't met our expectations, and we'll be stopping that program, and the reasoning to elaborate a little bit more about that. Let me take that one. You know, I think this was a very interesting program. There's a tremendous amount of unmet need in gout where patients progress, and we have the opportunity with RNAi to target xanthine dehydrogenase. An important biological question that we had going into the study was to what extent will hepatic silencing alone with the GalNAc conjugated siRNA be sufficient to produce enough uric acid lowering to be important for patients with gout?
That was something that was difficult to assess in preclinical models because of some of the limitations that are inherent in preclinical models of gout. You know, we did actually a very efficient small Phase 1 single ascending dose study in healthy volunteers. Through that, while the drug was safe and well-tolerated, and we did see some evidence of pharmacologic activity, the magnitude of uric acid lowering that we see here is not suggestive that this will be a transformative medicine for patients to get with gout. That's really what we're focused on here at Alnylam, is to bring forward transformative medicines. You know, based on this single ascending dose experience, we're able to make a decision, you know, data-driven decision that we shouldn't advance that program forward.
That's really the substance of what went into the decision-making here. We won't be advancing that program further and focusing our resources on other programs where we think we can make a bigger impact on patient health. Maybe question that came up is around if you could talk a little bit about, Dion, in terms of what are we looking for in terms of treatment effects. You talked about KARDIA-2, which is a combination study. What are we thinking about in terms of what would be clinically meaningful treatment effects as additive therapy on top of the various background medicines that you talked about?
Yes. Remember, in our Phase 1 study, we showed very effective reductions in blood pressure with angiotensinogen from doses from 200 to 800 milligrams. In that Phase 1 study, a reduction of systolic blood pressure of 10 millimeters of mercury or more, we thought was clinically meaningful with up to 20 millimeters of mercury reduction in blood pressure to the 800 milligrams. In KARDIA-2, where we're looking at the additive effects of zilebesiran on top of standard of care. The first one where we add zilebesiran to the common diuretic indapamide, we're expecting to see reductions probably around 10 millimeters of mercury or more. With the calcium channel blocker amlodipine, we're expecting to see additional reductions in blood pressure of at least 8 millimeters of mercury.
With the add-on to olmesartan in the angiotensin receptor blockers, we'd be interested in seeing reductions of 5 to 6 millimeters of mercury additional. Again, you know, it's a different effect for different types of classes of antihypertensives, but we're really looking to see what's the added blood pressure lowering efficacy to zilebesiran on top of the standard of care antihypertensive classes. Again, you know, we'll hopefully see the results at or around end of year next year, and that's really gonna help shape our Phase 3 clinical program, where we go, what types of patients we propose to use in our Phase 3 program to really, you know, assess the clinical benefit of zilebesiran, particularly in patients that have uncontrolled hypertension.
Great. Great. Rena, a question came in for you. How do you anticipate the pricing of ONPATTRO to be impacted by the potential launch in cardiomyopathy, assuming a positive FDA review?
Sure. Certainly an important, an important question. I think exactly what you were alluding to, we need to take this step by step. First, let's, as we announced last week, we did complete the submission of the sNDA with the FDA. The next step will be to get that, as John mapped out, accepted and then an approval later in 2023. Pending all that goes smoothly, we would then have the label, and that would be important for kind of further refining and shaping our pricing approach. I don't think we wanna go into too much detail on specific pricing, but I will make a connection here to our access efforts. I think access is really important as we heard, as a key unmet need in this space from Dr. Sarswat's talk, right?
What we've seen with ONPATTRO in the... and AMVUTTRA in the polyneuropathy space, has really been significant progress in aligning our access strategy, things like our value-based agreement strategy and really having broad access for patients with the hereditary ATTR amyloidosis with polyneuropathy and gaining strong access for both our ONPATTRO and AMVUTTRA products to date. We think that really serves as a strong foundation for what we're building for the future with ONPATTRO in the cardiomyopathy space potentially and then of course AMVUTTRA. I think those proactive efforts for access will be really important over the course of the coming year as well.
Fantastic. That's really helpful. We're getting down to the last just few minutes of the Q&A. We'll just have maybe one or 2 more questions. Maybe one, John, can you just talk a little bit about next steps with regard to TTRsc04? Question came in about really interesting, what do you see in terms of will we be able to take that program directly from Phase 1 into Phase 3? Will it go into PN and CM? What's the thinking about how we can develop that and how quickly we can develop it?
Yeah. Thanks, Pushkal Garg. Look, we are really very, very excited about the potential for TTRsc04. We are anticipating getting started on that Phase 1 study in the immediate future. Really looking forward to that and having top line results that we could share by the end of next year. With regard to the clinical development plan, how we're gonna move that forward, that's something that's still under discussion and considering, and we'll certainly share that in due course.
You know, I think with regard to moving things forward rapidly, I would just, you know, point to our track record with how we've been able to move things forward with Nucresiran and other compounds in our pipeline. We'll certainly look forward to sharing those clinical development plans as they become available.
Great. Thank you, John. Well, folks, I think this is really, the end of the time that we have for Q&A this morning in this first session. I really wanna thank John, Rena, Dr. Sarswat, Dion, for all of your input and the interesting discussion. We're gonna take a break, everybody, until 11:05 A.M., and then we'll resume with Part 2 of R&D Day, where there'll be an update on our early and mid-stage programs, as well as our platform efforts, and then a second Q&A panel after that. We're gonna break until 11:05 A.M., and I hope you'll all come back and join us for the second half of R&D Day. Thank you.
Hello everyone. Welcome back, and thank you for joining us for the second part of our R&D Day. My name is Weinong Guo. I'm currently leading the clinical research group responsible for all of the non-TTR programs at Alnylam. This morning you have heard about the progress Alnylam has made across the ATTR amyloidosis and hypertension programs. In the next 20 minutes, I will walk you through a number of very exciting earlier and mid-stage RNAi programs that are anticipated to drive the future organic growth of our organization by addressing high unmet medical needs in new disease areas for Alnylam. As we think about the excellent progress we have made in the late-stage pipeline, we continue to build the pipeline towards P5x25 and beyond. In this regard, we will be expanding our pipeline of liver indications.
We will also be expanding across rare specialty and permanent diseases. We will include programs targeting gene expressed in new tissues as well. The pipeline you see here begins to reflect those elements. I'd like to now to spend some time diving deeper into some of these programs. I will walk you through the 4 key areas of our pipeline that we believe hold significant potential, starting with assets that are wholly owned and then covering programs being advanced with or by our partners. This will include programs against genetically validated targets in the liver as well as other tissues. The 4 key areas of the pipeline that I will cover in this presentation are type 2 diabetes program, central nervous system programs, NASH programs, and partner-led programs.
Let me first start with our ALN-KHK programs, which represents our first RNAi therapeutics to address the unmet medical needs in type 2 diabetes and potentially other metabolic diseases. As we know, fructose intake and metabolism contribute to metabolic syndrome. This is of increasing importance because, as shown in the left part of the slide, dietary fructose supplementation is believed to contribute to the growing pandemic of obesity. Obesity and associated fatty liver are 2 profound risk factors resulting in insulin resistance and the development of type 2 diabetes. On the right shows the metabolic pathways of how fructose intake can produce many of the key features for the metabolic syndrome. Ketohexokinase, or KHK, also known as fructokinase, is the first enzyme in this pathway, so therefore constitutes an important therapeutic target for addressing the kinds of effects shown on the left.
It is important to note that loss of function variants in the KHK gene in human cause essential fructosuria, characterized by increased urinary fructose excretion. Overall is asymptomatic, benign, and usually does not require treatment. This piece of human genetic data provides preliminary safety support for silencing KHK with an RNAi therapeutic approach. An important way to test the hypothesis highlighted on the previous slide is to look at the high-fat diet-fed rodent model, where additional fructose or glucose intake creates derangement of glucose homeostasis. Preclinical data supporting the therapeutic hypothesis are shown here on this slide. With ALN-KHK, a GalNAc conjugated siRNA designed to specifically suppress the hepatic expression of ketohexokinase. Let's first look at what happens when you knock down the KHK.
As shown on the left part of this slide, the effect of ALN-KHK in non-human primates has clearly demonstrated dose-dependent and profound KHK protein knockdown at day 29, following a single subcutaneous injection. On the right, shown the rodent model of high-fat diet plus fructose or glucose-induced metabolic disorders. KHK knockdown with an siRNA led to improved insulin sensitivity, demonstrated by the reduced area under the curve of glucose levels in response to the glucose tolerance test. Taken together, these animal experiments established the pre-clinical proof of concept of KHK silencing in improving insulin sensitivity. Alnylam is on track to file the CTA for ALN-KHK by the year-end and initiate the Phase 1 study in early 2023. This randomized double-blind trial will be a first-in-human, single ascending dose in healthy OB subjects. We expect top-line results in late 2023.
This will be then followed by a multiple-dose proof of concept study in obese patients with type 2 diabetes. If the study described here is positive, there is a potential to continue the development of ALN-KHK in type 2 diabetes, and also the opportunity to expand development to other metabolic disorders, including fatty liver disease. I will now transition to our CNS portfolio. We have been building on the recent pre-clinical success of our CNS platforms with C16 conjugates, aiming to unlock a significant range of opportunities for RNAi therapeutics in the CNS space. Today, I'm not going to talk about ALN-SOD, which is in IND-enabling studies for amyotrophic lateral sclerosis, nor our program for Huntington's disease, where we are working towards a development candidate. I will be discussing ALN-APP, our first-ever CNS-targeted siRNA product currently in clinical investigation.
This program entered the clinic early this year, which exemplifies the potential of our platforms to treat CNS diseases. Early this morning, you heard the progression by John Vest on the success of our RNAi approach in treating ATTR amyloidosis. Building on the success of RNAi platform for other types of amyloidosis, ALN-APP is designed to reduce protein production of amyloid precursor protein, APP, that is upstream of amyloidogenic process. With ALN-APP, our therapeutic hypothesis is that by lowering APP protein production in the CNS with RNAi, we can reduce both the intracellular and extracellular aggregation of APP degradation products, such as amyloid beta, and thereby halt or improve the clinical manifestation of Alzheimer's disease and other chronic and debilitating amyloid-driven disorders.
As my colleagues in research will share with you in the next presentation, we have made tremendous progress with delivery of our drugs to the CNS. We have shown how we can achieve broad biodistribution, reaching deep brain structure, and where single intra-cerebral injections provide up to nine months of silencing of a target. Specifically, intra-cerebral administration of ALN-APP in non-human primates successfully produced profound and durable APP reduction over six months, as shown by APP alpha and APP beta levels reduction in cerebral spinal fluid. Importantly, as shown on the right, intra-cerebral dosing of siRNA targeting APP resulted in meaningful APP mRNA reduction across multiple deep brain and spine regions of non-human primates.
Taken together, these PD data highlights here provide evidence for effective and sustained suppression of APP mRNA and the CSF biomarkers when ALN-APP is successfully delivered into the intra-cerebral compartment, and then to the brain when administered by lumbar IT injection in non-human primates. Note, a key differentiator for our program would be the ability to reduce both intracellular and extracellular accumulation of the various protein species that come from APP degradation. This is possible by silencing the amyloid precursor protein production within the neuron. On this slide, we are pleased to show that an RNAi therapeutic targeting APP suppresses intracellular aggregates in neurons produced by induced iPSC cells derived from Alzheimer's patients. Between these last 2 Slides, you have preclinical data that supports ability to suppress both extracellular and intracellular accumulations of APP degradation products.
The amyloid precursor protein is best known for its connection to Alzheimer's disease, the most common cause of dementia worldwide, affecting $5 million in the U.S. and approximately $30 million people worldwide. Targeting APP with RNAi therapeutics is a novel approach in Alzheimer's disease, which acts upstream of this pathological process. This approach is designed to reduce APP protein at its sources, reducing both intracellular and extracellular drivers to disease pathology and all APP cleavage products, including all species of amyloid beta. We believe that targeting APP at mRNA level has the potential to provide a more comprehensive intracellular and extracellular impact to the disease pathology. Our preclinical data on the previous 2 Slides indeed support this hypothesis.
In addition to the opportunity for ALN-APP to address Alzheimer's disease, we believe that lowering this target may also have therapeutic applications in another disease called cerebral amyloid angiopathy or CAA. While Alzheimer's disease is characterized by the accumulation of amyloid plaques in the parenchyma of the brain, as well as the intraneuronal accumulation of tau tangles and neurodegeneration, CAA is a disease where amyloid plaque deposits in the vasculature of the brain, which can increase the risk for hemorrhagic strokes. CAA is the second most common cause of intracerebral hemorrhage after hypertension. It is a disease with high unmet medical need, today there are no specific treatment available to treat CAA and very little activity currently in clinical development. The therapeutic hypothesis for CAA is simple.
By reducing the production of APP and thereby reducing A-beta forty and all other amyloid species, we aim to interfere with the progression of amyloid deposits in the vessels and potentially enable natural clearance of the existing deposits, and thereby address some of the vascular damage that occurred during the disease. We have began this journey of development with ALN-APP with our Phase 1 randomized double-blind study in patients with early onset Alzheimer's disease. This study is designed in 2 parts, a single ascending dose Part A, followed by a multiple dose Part B. The primary endpoint of the study is safety and tolerability of ALN-APP. We also hope to begin to characterize the pharmacology of our CNS conjugates and assess the level of target knockdown we can achieve, as well as the duration of such effect.
We are currently enrolling patients in Part A and are progressing through the dose escalation portion of the study. We expect to share some of the preliminary data from this study in early next year. We expect the results of this Phase 1 study will help inform our next steps in the clinical development of ALN-APP. If successful, these results will de-risk further development in Alzheimer's disease. In addition, this study will also provide us useful insights into the pharmacology of ALN-APP and enable the initiation of development as a potential treatment for CAA. In this way, we aim to explore both potential opportunities and leverage the emerging data and evolving landscape in these indications to inform our late-stage development plan in the CNS space. The success of ALN-APP program will potentially de-risk other programs and future targets for our rich CNS portfolio.
Now turning to our NASH program. Our genetic colleagues at both Alnylam and Regeneron have identified a number of targets implicated in NASH, which include HSD17B13, PNPLA3, and CIDEB. We are now building an industry-leading portfolio of programs for NASH against these genetically validated targets. Today, I am going to discuss with you exciting proof of concept data we reported early this year for the first of those NASH programs, that is ALN-HSD. Nonalcoholic steatohepatitis, NASH, is a highly prevalent chronic liver disease in which inflammation and liver cell injury are caused by accumulation of hepatic fat. NASH is a subset of a group of conditions called non-alcoholic fatty liver disease, NAFLD, that can lead to progressive fibrosis, cirrhosis, and hepatocellular carcinoma. Comorbidity always include obesity, metabolic syndrome, and type 2 diabetes.
Approximately 5% of adults, that is 60 million people in the U.S., live with NASH, and the prevalence increasing due to rising rates of obesity and type 2 diabetes. There are currently no approved medical treatment for NASH, highlighting the significant unmet medical need in this space. Genome-wide association study have identified loss-of-function variants in the HSD17B13 gene, which reduce the risk of chronic liver disease and progression from steatosis to steatohepatitis. On the other hand, gain-of-function variants in the PNPLA3 gene that increase the risks and the strongest protection and increase risk in individuals homozygous for each of these 2 variants. These genetic validation data have motivated us to develop RNAi therapeutic targeting HSD17B13 and PNPLA3 in collaboration with our partner, Regeneron.
ALN-HSD is a GalNAc conjugate siRNA intended to mimic the genetic loss of HSD17B13 function to halt or reduce hepatic injury, fibrosis, and inflammation that occurs in NASH. We carried out a Phase 1 study of ALN-HSD, which is a randomized, double-blind, placebo-controlled, multicenter, single ascending dose and multi-dose studies to evaluate the safety, tolerability, PK, and PD effects of ALN-HSD in healthy adult subjects, as well as in adult patients with NASH. The Part A enrolled healthy adult subjects to receive a single ascending dose of ALN-HSD from 25 mg all the way up to 800 mg. Part A of this study has been completed. For Part B, it enrolled patients with NASH to receive 2 doses of 25, 200, or 400 mg of ALN-HSD or placebo via quarterly subcutaneous injections.
Patient underwent paired liver biopsy at baseline and month 6 or month 12, depending on the cohorts. Patients in all cohorts of the Part B have completed at least 6 months on this Phase 1 study. ALN-HSD has exhibit an encouraging safety and tolerability profile to date. The most common treatment-emergent adverse events is in healthy subjects treated with ALN-HSD, was injection site reactions in 5 patients out of 44 healthy subjects. All injection site reaction was mild in severity. No treatment-related serious SAEs have been reported in either healthy volunteers in Part A or patients with NASH in Part B to date. The pharmacodynamic effect of ALN-HSD was assessed by hepatic HSD mRNA levels at month 6. These data were reported by press release early this year, are being shown here in graphic forms for the first time.
As you can see on the left, ALN-HSD, those dependently suppressed liver HSD mRNA levels. 2 quarterly dose of ALN-HSD, 25 milligram, 200 milligram, and 400 milligram, resulting in a median reduction in HSD mRNA levels of 40%, 71%, and 78% respectively, compared to the observed 5% increase in placebo group. It is noted that 1 patient in 400 milligram dose group missed the second dose at month 6, as shown in this red dot data p-point here, but still achieved approximately 55% knockdown 6 months after the single dose of 400 milligram ALN-HSD. There is a positive trend in lowering the liver enzyme, as shown on the right chart, and improvement in the biopsy-derived NAFLD Activity Score over 6 months in patients receiving ALN-HSD relative to the placebo.
This study was not powered to achieve the statistical significance on these exploratory endpoints, we are planning to present these exciting PD safety and exploratory efficacy data at the medical conference next year. The data you have seen by targeting a genetically validated target like HSD give us a lot of excitement. Our next generic target, genetically validated target in NASH is PNPLA3. This is a lipid droplet associated protein predominantly expressed in liver. Numerous GWAS reports have shown that ALN-PNPLA3 risk allele variant is associated with hepatic steatosis, inflammation, fibrosis, and cirrhosis. Some of the reasons we are excited about the potential for ALN-PNP are illustrated here. Published data shown on the left plot are from a preclinical NASH model, which use of an antisense oligonucleotide to lower PNPLA3 resulted in improvement in a number of histology parameters, including steatosis, inflammation, and fibrosis.
On the right, you can see that we have already identified a number of highly potent and durable siRNAs, both in rodents and non-human primates. Importantly, as these 2 targets I highlight here, HSD and PNPLA3, address different aspects of the pathology of the NASH, they may be well-suited to be used in combination to treat this disorder. This is certainly we are evaluating with our colleagues in Regeneron, and we look forward to share more data of this exciting programs in the future. Our partner, Regeneron, will now be advancing the ALN-HSD program from Phase 2 onwards. They have also recently filed the IND for ALN-PMP, and plan to initiate a Phase 1 study in early next year. Finally, I would like to quickly share with you some highlights of 3 partnership-led programs in which Alnylam retains substantial economics and contribute to the future growth and value creations.
These programs include ALN-HBV02, also now known as VIR-2218, for chronic HBV infection, Fitusiran for hemophilia A and B with or without inhibitors, and Cemdisiran- Pozelimab combo regimen for myasthenia gravis and paroxysmal nocturnal hemoglobinuria. Chronic HBV infection remains an urgent global public health challenge associated with significant morbidity and mortality. Approximately 290 million people around the world are living with HBV, and approximately 900,000 of those die from associated complications each year. These patients are significantly underserved by existing therapies with low functional cure rates, lifelong daily therapies, and poor tolerability. Our partner, Vir Biotechnology, is evaluating a combination regimen of VIR-2218 and VIR-3434 as a potential functional cure for HBV.
As you know, VIR-2218 is an investigational subcutaneously administered RNAi therapeutic targeting HBV that was discovered by Alnylam scientists, whereas VIR-3434 is an investigational subcutaneous administered antibody designed to block the entry of HBV virus into the hepatocytes. In the recent AASLD Congress in November in Washington, D.C., the top line results of Phase 2 MAXX study were presented demonstrating that VIR-2218 and VIR-3434 combination regimens achieved mean surface antigen reduction 2.5 log or greater in all cohorts. We have reported absolute surface antigen level less than 10 unit per millimeter achieved in most participants over 20 week of treatments. Patterns of response demonstrate additive surface antigen reduction from the complementary modes of the action of these 2 agents. All AEs were mild to moderate in severity. There were no AEs leading to treatment discontinuation.
We are very excited about these Phase 2 study results that suggest the transformative potential of the combo regimen for the functional cure of chronic hep B infection. There are several additional Phase 2 readouts expected from Vir during the course of next year. Importantly, Alnylam has an opt-in right prior to Phase 3 development. As for Fitusiran, this is a first-in-class RNAi therapeutic targeting antithrombin discovered by Alnylam. Sanofi is conducting multiple Phase 3 study designed for patients with hemophilia A or B, with or without inhibitors. As depicted on this slide, 3 Phase 3 studies were conducted in adults and adolescents, with all trials demonstrating statistically significant reduction in bleeding and a median analyzed bleeding rate of 0 in Fitusiran-treated patients across the spectrum of hemophilia patients studied. Not shown on this slide, Fitusiran prophylaxis also significantly improved health-related quality of life in these treated patients.
The most common treatment emergent AEs of special interest for Fitusiran were liver enzyme elevation greater than 3-fold of the upper limit of normal. The vast majority of these LFT elevation returns to normal and did not result study discontinuation. There were a small number of suspected or confirmed thromboembolic events in the Fitusiran arm across the three studies. Additional Phase 3 studies where lower doses are expected in late 2023, with an NDA submission expected in 2024. Multiple ongoing studies with Cemdisiran and RNAi therapeutic targets targeting complement C5 discovered by Alnylam and the Pozelimab, an antibody against C5 discovered by Regeneron, are being conducted by our partner, Regeneron, to evaluate the role of this combination therapy with potent inhibition in C5 in 2 complementary mediate disease, myasthenia gravis and PNH.
In summary, we see multiple opportunities to advance our innovative RNAi therapeutics against hepatic and extrahepatic targets to address diseases of high unmet medical need, such as the ones I have shown you here today. Importantly, we continue to focus on genetically validated targets, which increase the probability of success. We have an increasing focus on specialty and large market opportunities, which is enabled by emerging safety profiles of our technology platform and the pharmacological profile of our molecules, which offer the potential for durable tonic control of target gene expression with infrequent dosing. I would like to thank you very much for your attention and will now turn it over to my colleague, Aimee Deaton. Thank you.
Thank you, Weinong. Hello, I'm Aimee Deaton, Associate Director of Human Genetics, and I'm gonna talk to you today about some of our work using genetics to find exciting new therapeutic targets. After that, Vasant Jadhav will speak to you about some of our recent innovations in our platform. Why use genetics to help find drug targets? Well, we know that drug development has a high rate of failure, with the vast majority of drugs that go into development failing to get regulatory approval, primarily for reasons of efficacy and safety. Why is this? Well, one reason is that animal and cell-based models traditionally used in drug discovery do not fully recapitulate human biology and physiology. We can overcome this challenge by using natural genetic variation in humans to inform drug discovery.
It's been shown that targets with genetic validation are twice as likely to lead to approved drugs. By this, we mean that mutations in the gene encoding the drug target lead to a phenotype that matches the desired effect of the drug. Evidence coming from rare protein coding variants, such as those captured by exome sequencing, have the greatest effect on probability of success. In fact, if you look at Alnylam's historical probability of success, you can see that it's many times higher than industry standards. This is in part due to our focus on genetically validated targets and genetic disease. Because we want to continue this success, we've made a significant commitment to genetics. First, through our involvement with the U.K. Biobank, a cohort of 500,000 people with rich Health-related information.
We were part of the consortium, the Exome Sequencing Consortium, and are now part of a group performing proteomic profiling on a subset of the cohort. Several highly impactful findings have come out of our work in U.K. Biobank. This includes the association of prevalent U.S. TTR mutation V122I with the polyneuropathy manifestations of ATTR amyloidosis. It also includes the association of INHBE loss of function with abdominal obesity, which we introduced last year as Gene X, and on which I'll elaborate today. We also have found a new target, which we're calling Gene Y, for Type 2 Diabetes. We continue to access new genetic data sources, and we're founding industry members of Our Future Health, which is collecting genetic and health information on 5 million people.
This is 10 times as many people as in U.K. Biobank, and you can just imagine the scale of the targets that we'll be able to make using this data set. In addition to our internal data, we collaborate with Regeneron Genetics Center. They have access to additional cohorts and data from health systems. They discovered HSD17B13 as a target for NASH, which you've just heard Weinong talk about, and they provided independent validation of our finding for INHBE. In addition to these data sources, we have a strategic eye focused on what new data sources we can access in the future. At last year's R&D Day, we introduced INHBE as Gene X. We were really excited by the finding that loss of function in INHBE associates with lower waist-to-hip ratio.
We found this using our U.K. Biobank exome data, and we replicated it using data from the T2D-GENES Consortium. This finding was recently published in the journal Nature Communications. Strikingly, carriers of loss-of-function variants in INHBE, who have on average a 50% decrease in INHBE, have a really favorable metabolic profile. This includes lower triglycerides, lower alanine transaminase levels, suggesting better liver health, and lower fasting glucose. They also have fewer metabolic syndrome traits than non-carriers. The reason studying the genetics of waist-to-hip ratio is important is it directly reflects abdominal fat and causally affects risk for type 2 diabetes and heart disease. Consistent with this, carriers of INHBE loss-of-function variants have fewer cases of coronary heart disease and type 2 diabetes.
This is true for other waist to hip ratio lowering genes in our study, with disease protection being proportional to the effect on waist to hip ratio. Another reason INHBE is such a compelling target for us is that it's exclusively expressed in the liver, making it an ideal target for our platform. INHBE encodes activin E, a secreted protein which we believe binds to receptors on adipose tissue. While efforts to characterize the receptors and signaling pathway are ongoing, we can silence INHBE using RNAi and directly impact the causal gene prior to discerning these details. Through doing this, we may impact cardiometabolic disease in a way that's mechanistically distinct from current therapies. We were inspired by our finding for INHBE to look for targets to address unmet need in other common diseases, and we focused on type 2 diabetes.
This is because half of type 2 diabetes patients fail to reach target HbA1c on current treatments, with low rates of compliance for many therapies. Many of these patients progress to requiring supplemental insulin. T2D is a multifactorial disease, but we believe we can influence key aspects of the disease through the liver. Because of this, we focused on identifying liver-expressed modulators of insulin signaling whose silencing might improve type 2 diabetes. We did this by searching for genetic variants that reduce type 2 diabetes risk. We identified Gene Y, encoding a negative regulator of insulin signaling, and this gene harbors a damaging missense variant that reduces risk of type 2 diabetes as well as HbA1c levels. To test the impact of Gene Y on insulin sensitivity, we silenced Gene Y in the livers of obese mice.
We saw a blunting of the hyperglycemic response in these mice as measured by a glucose tolerance test, and we saw improved insulin sensitivity. You can see that the siRNA-treated mice, shown in blue here, have glucose and insulin tolerance comparable to lean murine animals . Strikingly, this was achieved without any increase in body weight. In fact, we might be seeing a trend towards decreased body weight in the siRNA-treated animals. Additional compelling observations in these treated mice included enhanced insulin sensitivity in extrahepatic tissues, reduced liver fat, and reduced HOMA-IR. Alnylam has been a pioneer in using genetics to identify therapeutic targets, and we are continuing to invest in genetics to identify new targets and continue our run of clinical success. The genetics of INHBE make it a compelling target for cardiometabolic disease, and we're aiming to have a development candidate for INHBE in 2023.
Using genetics, we identified a new target, Gene Y, for type 2 diabetes. Consistent with the genetics, hepatic silencing of Gene Y improves insulin sensitivity in obese mice. I've talked to you today about new liver targets identified through human genetics. I'm now gonna hand off to my colleague, Vasant Jadhav, who's gonna talk to you about some exciting innovations in our platform. This includes delivery to new tissues where there are additional genetically validated targets that we can silence to address unmet medical need. Over to you, Vasant.
Thank you, Aimee. Hi, everyone. My name is Vasant Jadhav. I lead our RNAi platform technology efforts. I'm thrilled to share with you the platform advances as a source of sustainable innovation at Alnylam. Aimee talked about the first source of this sustainable innovation, where we learn from Mother Nature's experiments to gain clues for novel targets of therapeutic interest. The other 2 sources are, the first one, platform designs, and the second one, extrahepatic delivery expansion. Both benefit from our long track record of industry-leading RNAi platform. Our siRNA designs include IKARIA platform that enables robust and specific target knockdown based on all our previous advances with annual dosing potential. GEMINI is our approach of combining 2 siRNAs as a single chemical entity. Finally, the REVERSIR oligos that provide tailored control of RNAi pharmacology. The next source of our innovation is delivery to extrahepatic tissues of interest.
These targeted delivery approaches are benefiting from lessons learned from our GalNAc siRNA delivery platform. Let's begin with advances in the platform designs and dig deeper into that. As I mentioned earlier, IKARIA platform provides the potential for robust knockdown with annual dosing potential. The data shared here is for TTRsc04. As my colleague John Vest shared earlier, TTRsc04 CTA has been submitted. As shown in the data here, the RNA-seq analysis shows exquisite specificity for TTR knockdown. NHP data in the middle graph shows high level of potency and our modeling data suggests or it predicts potential for once a year dosing in humans with greater than 90% TTR protein reduction. Making such molecules is a norm for us. These advances are also utilized for our GEMINI platform.
Gemini, or in other words, Bis-RNAi platform, combines 2 siRNAs via a proprietary linker to obtain a single chemical entity. This will be particularly useful in indications involving role of multiple genes from same or different pathways. For example, elevated blood pressure and higher cholesterol are the top 2 leading risk factors for cardiovascular disease. What are the potential benefits of Gemini or Bis-RNAi design? We believe by combining 2 siRNAs in one molecule, it potentially simplifies clinical development path compared to 2 entities or the combo. It also ensures uptake of both siRNAs in same cells across tissue types and provides controlled parallel reductions in the 2 targets. Let's see how well this design is working.
Again, based on our deep expertise in siRNA designs and delivery, we now have a GEMINI GalNAc construct that includes a proprietary linker allowing subcutaneous reduction of 2 different liver targets. The data shown here is in NHP, where GEMINI platform shows potent and durable activity comparable to the mixture of 2 parental siRNAs. We can take the lessons learned from here and also apply them for CNS GEMINI design. Obviously, in that case, a different ligand for delivery would be needed. In CNS indications, there are multiple genes implicated in Alzheimer's disease, in ALS, in Parkinson's disease, and others. As shown in the data here, GEMINI C16 design is providing excellent RNAi activity in rat CNS when dosed by intrathecal dosing. The activity of GEMINI C16 is comparable to that of mixture of 2 siRNAs.
One of the defining features of our siRNA designs is their remarkable durability that allows very infrequent dosing. While long-acting agents are very desirable for compliance and other reasons, there may be cases where the ability to reverse a long-acting agent would be desirable. The concept of antidotes or reversal agents is not a new one, and it is widely used in the medical practice, with few examples shown in the table on the left here. In this regard, we have previously reported REVERSIR platform. The name REVERSIR comes from combining the words reversing siRNA activity. This approach is oligonucleotide sequence-based, utilizes same GalNAc ligand for delivery, and is amenable for subcutaneous route for dosing. We have done several proof of concept studies designing and administering REVERSIR agents targeted to some of our long-acting molecules. One example I show here is the reversal of zalvistrand RNAi activity.
zilebesiran is our investigational compound for blood pressure lowering. In this NHP study, zilebesiran was given at 3 mg/kg dose, and the blue line indicates robust reduction of circulating AGT protein. Dosing of the REVERSIR at 22 days results in rapid rebound of serum AGT levels within days. With long-acting pharmacology of zilebesiran, REVERSIR offers an option for the rapid reversal of the drug effect as shown by this data. Moving to the next source of platform innovation, that is extrahepatic delivery expansion. RNAi therapeutics approach in CNS diseases is very appealing as there are no current therapies for neurodegenerative diseases. There are number of genetically validated CNS targets. We believe this provides significant opportunity for RNAi therapeutics in CNS space. Earlier this year, we published our work on C16 conjugate platform in the Journal of Nature Biotechnology.
This paper was selected by prestigious Oligonucleotide Therapeutics Society as the paper of the year in basic research category. This is our second year in a row for such an award. Last year, it was awarded to our conjugate siRNA durability work published in the Journal of Nucleic Acids Research. For C16 platform, we conducted exhaustive optimization of lipophilic moiety, its position and included siRNA modifications like vinylphosphonate, a stable phosphate mimic to improve the potency. How do these C16 siRNA conjugates show activity across CNS regions? Here is the data utilizing MERFISH technology that allows spatial resolution of target mRNA knockdown within tissues. After single ICV injection in mice, our scientists evaluated the target knockdown by MERFISH, and the data speaks for itself.
The control on left shows ubiquitous expression of target mRNA, and with the C16 siRNA treatment, we see robust knockdown across brain regions of these mice. This is particularly exciting as brain is a complex organ, and this data shows it is feasible to achieve knockdown by C16 siRNAs across all regions of the CNS. Based on the C16 siRNA conjugate technology, we have designed siRNA molecule targeting amyloid precursor protein. With a single IT dose in NHP, we observe robust and durable knockdown as shown here. My colleague, Weinong Guo, earlier talked about the ongoing ALN-APP Phase 1 study, and we expect the initial data in early 2023. In the C16 siRNA conjugate publication that I mentioned earlier, we also showed functional benefit in the mouse model of Alzheimer's disease by APP C16 siRNA.
Now we show another example with C16 siRNAs, this time targeting alpha-synuclein, demonstrating benefit in the mouse model of Parkinson's disease. We designed the C16 siRNAs targeting SNCA and evaluated them in collaboration with our partner, Regeneron. These homozygous transgenic mice overexpress A53T alpha-synuclein and show phenotype of the Parkinson's disease. We conducted the study in prevention as well as therapeutic paradigm, as described on this slide with the experimental details. Remarkably, the data shows administration of SNCA siRNAs, the C16 siRNAs, prevent alpha-synuclein aggregation and spread in preventive as well as therapeutic dosing paradigm. In addition, in the behavioral test shown on right, SNCA siRNAs prevent motor deficits by reducing the number of falls. This is the second example of C16 siRNAs showing functional benefit in the mouse model of CNS disease.
Beyond liver and CNS, we know that RNAi machinery is present in all biological tissues, and we have optimized the siRNA design for in vivo delivery based on all our experiences for liver delivery. It is really about delivering these highly modified siRNAs to the tissues and the cell types within those tissues, where lowering the targets of interest could have benefit in various disease states. We are doing this by broadening the range of ligands and receptors. The left panel shows potency improvements of our GalNAc siRNA targeted delivery conjugates over time in mice. Learnings from these efforts serve as a blueprint to expedite the extrahepatic delivery efforts. Ideally, we are looking for something like a GalNAc ligand that is small in size, provides potent knockdown and works by subcutaneous delivery, and importantly, also has CMC benefits for development.
To support these efforts, we have expanded our core capabilities for ligand receptor characterization. In addition to that, ligand discovery internally as well as externally through collaborations like PeptiDream, where we continue to make progress in finding peptide-based ligands against multiple receptors of our interest. Let's go through some of the examples of data in 4 different tissues, and to begin with, CNS. As we discussed earlier, C16 conjugates show robust activity in CNS after intrathecal dosing. We now report a ligand that appears about 3-fold better than C16 for activity in NHP by intrathecal dosing. It is very important for us to keep improving the potency to reduce the dose lower and lower, and this is just another example of our continued innovation. The next example is for delivery to skeletal muscle. Here we identified another ligand, for now calling it as ligand B.
We are seeing dose-dependent and potent knockdown in mouse skeletal muscle at doses as low as 1 milligram per kilogram, while minimal activity is seen in liver, even at the higher doses. Importantly, these conjugates are also amenable for subcutaneous dosing. As expected from our siRNA designs, the durability looks good in skeletal muscle. The next example is for heart delivery. Here we use ligand C siRNA conjugate that is amenable to multiple routes of administration, including IV, intramuscular, subcutaneous, intraperitoneal, all of them showing robust knockdown. The middle panel shows dose-dependent knockdown in heart after IV dosing. We have taken these conjugates further in non-human primates showing knockdown in heart. Finally, delivery to the adipose tissue. Here we are using ligand D conjugate that shows robust knockdown in various adipose depots in non-human primates.
The immunohistochemistry and the in situ hybridization assays were used to show test article that is siRNA exposure and importantly, robust mRNA knockdown. These conjugates are also amenable to subcu or IV dosing, as assessed by the mRNA and protein levels. In summary, we think that all these delivery advances open door to many potential therapeutic opportunities across range of tissues beyond liver and CNS. Once we made the critical advances in liver delivery, this led to 5 drug approvals in 4 years, showing our proven ability to rapidly capitalize on the scientific advances. Our CNS journey has started with ALN-APP. Now we are evaluating other tissues of interest where delivery is looking promising and there are many targets with therapeutic opportunities.
In summary, our multiple sources of sustainable innovation, including, as Amy talked about, the human genetics efforts, siRNA designs, including IKARIA, GEMINI, REVERSIR, and delivery beyond liver, including CNS, skeletal muscle, adipose tissue, and examples like that, we believe this should continue to drive our organic engine for robust pipeline growth for years to come. With that, I would like to thank you for your attention. Now we'll move to the Q&A session. Thank you.
Good afternoon. Welcome everybody to the Q&A. I'm Kevin Fitzgerald, I'm our Chief Scientific Officer. I'm here with Akshay Vaishnaw, our President, Weinong Guo, our Senior VP of Clinical Research, Aimee Deaton, our Associate Director of Human Genetics, and Vasant Jadhav, our Senior VP of Technology. I hope you all are as excited about the presentations in the previous session as we are, really as we continue to extend and harness, you know, this revolution in biology for human medicine called RNAi therapeutics.
Not only maximizing what we can do in the liver, as you've seen time and time again, but now also extending that into organs such as the central nervous system, skeletal muscle, adipose tissue and others. With that, we're gonna jump into a bunch of questions coming in. I'm gonna start a little bit around there are a lot of questions around APP. I'll start off with a question to Akshay, sorta around what data can we expect from the Phase 1 in APP, you know, in early 2023, and really kinda what level of knockdown would you consider, you know, significant and why?
Sure. Thanks, Kevin. Hello to everybody, and thanks for joining us on our R&D Day. Let me answer the second part, maybe Weinong, you can help us with the data expected from the APP Phase 1 study early 2023. I think the question of the degree of knockdown obviously is a very interesting, important one. One area that gives us good insight is looking at individuals with trisomy 21, individuals that live with Down syndrome. They have a triplication of the chromosome resulting in three copies of the APP locus, so a 50% increase. That turns out to be a very powerful genetic association with the development of Alzheimer's at a premature age.
That gives us some clue that, you know, about 50% reduction, which would be consistent with maintaining safety, we believe, based on all our animal work, would be a good target to aim for for therapeutic benefit. About 50% is what would be interesting to see. Beyond that, in terms of the expectations of Phase 1, what data we can expect and so forth, Weinong, do you wanna pick up on that?
Sure. Thanks, Akshay. As I presented, we are currently launching a Phase 1 study, being conducted in U.S., U.K. and Canada. We are nicely progressing the single-ascending dose cohort. We expect that, you know, some of the emerging data will be available from that, you know, single-ascending dose cohort in early 2023. Stay tuned. We will report those data out once we got to the, you know, nicely progressing through the as per study protocol. Thank you.
All right. you know, sort of riffing on APP a little bit more. One of the questions is around, you know, mechanisms. Obviously there are APP, or beta amyloid-targeting antibodies out there. you know, Akshay and Weinong, one of you wanna comment a little bit about sort of the differences, you know, mechanistically we expect to see, as well as, you know, the current landscape out there, with the antibodies in this disease?
Yeah, I'll start, and Weinong, please do join in. I think, look, in the first instance, the recent news about lecanemab from Biogen is very important and exciting. It's a validation of the APP hypothesis that has been so troubled. Finally, we're seeing that extracellular reduction of APP is associated with cognitive benefit in patients. Let's see what happens to that drug. Hopefully it will get approved and start helping patients. I think separately what we're interested in addition is the ability to silence APP proximally at the message level, and so reduce APP-related fragments, both intracellularly and extracellularly. There's a wealth of information now that's accumulated on the neurotoxic effects of intracellular APP fragments.
I thought Weinong nicely showed in one of his slides iPSC-derived neurons from presenilin mutated patients who have Alzheimer's, how we reduce the accumulation from RAB5 positive endosomes, which are a hallmark of intraneuronal toxicity in Alzheimer's. I, you know, I think the antibody news is exciting. We hope to do more by reducing not just the extracellular deposits, but the intracellular effects of toxic fragments from APP. You know, looking forward to the Phase 1 data in early 2023.
Just one follow-up question?
Weinong, maybe you can add something.
Weinong, anything? Yeah.
Yeah, I think, you know, Akshay, you explained very well. I just want to add that APP sits on the very upstream of the amyloidogenic , you know, process. We expect to see, you know, silencing a number, a variety of the amyloid, you know, cleavage products, both intracellularly and extracellularly. We think targeting this genetic target will offer us a well-differentiated profile versus some, many of the others, monoclonal antibody currently in clinical investigation. Stay tuned, and once the data come out, and happy to report and share. Thank you.
A little bit further, Weinong. You know, if you think about silencing of APP, you know, is there such a thing as going too low? Where, where are we targeting, similar to a question before? Also, can you talk a little bit about this disease called CAA, and why we think that silencing APP could be, you know, beneficial in those patients?
Yes. Oh, a good question. Thanks, Kevin. For the CAA, as we know, this is just a different phenotypic of the, you know, enhanced or increased amyloidosis, and particularly as I shared in my presentation, these are the amyloid deposits in the vasculature of the brain. We are very eager to looking at the, you know, how the C16 conjugates through the intrathecal administration of ALN-APP demonstrated in the early onset Alzheimer's disease.
If we clear that, you know, a gating mechanism, we certainly is very much looking into the potential of conducting a proof of concept or additional studies in the CAA, doing some, you know, expansion programs, building on the scientific rationales.
Thank you, Weinong. you know.
I mean, I see.
A couple final questions. Oh, go ahead, Akshay.
Yeah, no, I was just gonna add, Kevin, I always see this wonderful analogy to our work with TTR and ATTR-related disorders that you have this one protein, the proteolytic fragments of which mediate, you know, the severe neurodegenerative phenotype, Alzheimer's, and we hope to help there. Using the same mechanism with the same protein, we also hope to help this very other phenotype, the cerebral amyloid angiopathy, which causes hemorrhages and ultimately large strokes. I just think it's a really powerful opportunity for 2 major neurological disorders. Again, we're all excited about the data that we hope to see in early 2023.
Thank you, Akshay. You know, final 2 questions around this particular topic. One, I gotta put this over to Vasant. A couple of questions came in around A, you know, the, our duration of action and how it differentiates from antisense oligos and the other things and other oligos in the field. B, have we thought, and are we working on perhaps trying to get away from intrathecal dosing and get across the blood-brain barrier?
Yeah, that's a great question. Thank you, Kevin. Historically, I mean, the data that we took for the siRNAs and the antisense oligos for liver targets, we do clearly see the benefit with RNAi technology or with our siRNAs in terms of the durability of effect, and we have published this work. That's the reason we can do every quarterly or in case of inclisiran is every 6 months. Now with IKARIA, we believe we'll be going every one year injection. That's the kind of potential. To our knowledge, I mean, we are not really seeing the antisense oligos that go beyond weekly or monthly kind of dosing regimen. We believe that benefit will continue to remain with the siRNAs. Can you remind me the second part?
The second part was around blood-brain barrier work.
Yeah.
I mean, I can take that one quickly and that, you know.
Yeah.
Obviously getting across... Oh, go ahead. I was gonna say, getting across the blood-brain barrier-
I would say that.
Has always been the goal. Sorry, we have a little bit of a delay. You know, I think, you know, we continue to work in that area, to make sure that if there's a true breakthrough in that area, that we're all over it. Right now we're very confident with very infrequent IT dosing, that we'll be able to treat a lot, you know, go after a lot of these diseases. I'm gonna turn a little bit to a bunch of questions. Go ahead, Vasant. Finish.
I would just exactly was going to add that same point that we are pleased with what we are seeing with the C16 siRNAs. I mean, we saw the data in NHP, right? It is for months with a single injection, we're seeing potent and very long-lasting activity. with that kind of approach, making it very infrequent, potential for a very infrequent IT dosing, that still is a great option.
Right. I'm gonna turn now to HSD, and, you know, presented a little bit of the data today, and maybe, Weinong, can you talk a little bit about the program and then maybe actually wanna join in around questions around why, you know, why did we opt out of that program? How does that program relate to, you know, PNPLA3, which is another program in that space, and how do we think about those targets? Maybe start with Weinong, and Akshay, you can jump in.
Sure. Thanks, Kevin. As I presented, we have, you know, obtained quite positive, you know, I think to us is a proof of concept in the first Phase 1 studies with ALN-HSD, shows a dose-dependent lockdown of the HSD mRNA level, with a liver biopsy, well tolerated. That's a primary objective of the study we conducted. We are very pleased to see some preliminary, you know, liver enzyme data show you the nice reduction as well as the, you know, histology, a nice trend, although the study is not particularly powered for those endpoints. We are looking forward to share more of these data through the, you know, maybe next year present as a major scientific congress.
In terms of next step, Regeneron is leading the HSD programs, and very soon, you know, a Phase 2 study will be launched to further evaluate the efficacy in the NASH patients. Akshay, do you have anything additional to add about the, you know, the opt out of the-
Let me just pick up on that, Weinong and Kevin. I think we're obviously delighted with the Phase 1 data. I think it's probably, I don't know, we're double digits in terms of numbers of proofs of concepts we've achieved in early development. It's really an exciting result. It's a full validation of the selection of the target that came from the original genetics at Regeneron. The data fall exactly in line with the expectation of the putative role of the target in the pathogenesis of NASH. Not only do we see target reduction, but we also see improvements in transaminases and most importantly, improve changes in the NAFLD score. You know, HSD obviously is a gatekeeper to further NASH progression from the steatosis check space. That's exciting.
Whilst we're excited about the data and very confident about the future of our program in the hands of Regeneron, I think, you know, we're in the wealth of riches and we have really a full portfolio, and we're gonna continue to make the best decisions we can to focus our resources on the highest value opportunities where we can deliver the best products for patients. We're also gonna continue to support Regeneron with HSD. We're gonna be very actively involved in the rest of the NASH portfolio that we work on with them, PNP, Site B and other targets. You know, there's plenty here for us to contribute and help with that will help patients and also help build value for Alnylam.
Thanks, Akshay. You know, just staying with HSD for and PNP for 1 second, I'm gonna question over to Aimee. Aimee , a question came in about sort of the genetics of PNPLA3 and HSD, and, you know, is there any potential overlap between the two? And are they or could they potentially be used together?
Yeah. I think that's a really interesting idea. The idea of a combination approach is supported by genetics showing that the risk reduction conferred by the protective allele of HSD is greater in carriers of the PNPLA3 I148M allele. As you know, Regeneron is advancing those programs, so it will be up to them to entertain this possibility, but it's definitely an interesting one.
Thank you, Aimee . Moving on from HSD, a lot of questions here from people about REVERSIR. In particular, around, you know, how do we think of the need for REVERSIR or the development? What would a Phase 1 look like? You know, maybe I'll start with Weinong and Akshay, you can certainly chime in.
Yeah. Great questions. We are, you know, as a clinician and drug developer, I'm very pleased to see that we now have the technology to develop a REVERSIR that may be warranted in certain clinical circumstances. As you heard earlier from Dr. Dion Zappe's presentation, particularly focusing on zilebesiran. Vasant showed you some of the nice data of the AGT reverse with our REVERSIR in non-human primates. We think, you know, probably the first potential clinical scenario are those in particularly, situations, when you need a REVERSIR, you know, clinical settings that can reverse the hypotensive or other, you know, effects, imposed by the angiotensinogen.
I think, you know, we are currently, we are looking into the clinical candidate or development candidate and hopefully bring it to the clinical development in the near future. Difficult to talk about the earlier programs, you know, clinical development plans at this point, but happy to share in the future opportunities. Thank you.
Yeah. Let me just build on that, Weinong. You know, I think the interesting thing about our technology is that we have the flexibility to have reversi-like approaches if needed. That's, it just shows the power of our platform, and I thought Vasant's slide very nicely illustrated that. Most importantly, so far, the safety for zilebesiran has been outstanding. You know, we're in Phase 2. It continues to go well. In the Phase 1 study, we saw how even in salt and water depleted patients, you didn't see an exaggeration of the hypotensive effect, and patients tolerate zilebesiran well.
Dion discussed how, you know, in any situations where there's lowering of blood pressure with zilebesiran, if you want to increase blood pressure, I think talking to our experts and looking at the mechanism of action, just giving saline would probably do the trick actually, in most cases it looks like. Now, having said that, as with, you know, other classes of medicines, most recently ten and ten A inhibitors, you know, novel anticoagulants where there are reversal agents, I think it's wise to have something like this in our back pocket. Let's see if we ultimately we'll need to develop it fully. There's certainly no requirement that's been made to us as yet. Clinically with the progress of the program, we're very comfortable.
Certainly, it's a wonderful example of what our technology can do if needed.
All right. Moving on from REVERSIR, I wanna talk a little bit about the HBV program, and there were some questions about sort of, you know, the degree of knockdown and what, you know, what does a, you know, functional cure mean? Maybe, Akshay, you can, you know, weigh in on that one.
Yeah. I mean, with The FDA actually has issued guidance documents on drug development for hepatitis B. Functional cure with respect to hepatitis B surface antigen means you basically have to become undetectable, and then you have to maintain that undetectable status of treatment for six months or longer. That's been the guidance, and we're fortunate to have that. It's a readily measurable biomarker, as you saw with the data that Weinong shared. I'm sure as the Phase 2 data start coming in later this year across multiple trials, our colleagues at Vir who lead this opportunity will share more, not just about the data, but the further development and how the data is guiding that.
anything to add, Weinong ? No, we're good.
No, I think that's perfect. Yes. Very exciting data.
So let's-
You know.
I agree, very, very exciting and, you know, certainly a lot of unmet medical need. I'm gonna move on to, you know, a couple of newer targets, questions that have come in. Very exciting to have revealed Gene X from last year being Inhibin E, and now we have Gene Y. A couple questions for Aimee. One, you know, if you think about Inhibin E, what are we looking at in terms of and thinking about in terms of indication? You know, a question a little bit around Gene Y, sort of the same question and how are we thinking that these agents will differentiate in the cardiovascular metabolic space?
Thanks, Kevin. Good questions. In terms of INHBE, we're considering multiple indications in cardiometabolic disease. I think a major differentiator for INHBE is a distinct mechanism from current therapies. All right? We believe it will decrease abdominal fat and improve insulin sensitivity with additional potential benefits on lipids and blood pressure. We see this really as a likely complement to targets for cardiometabolic disorders. In terms of INHBE... Sorry, in terms of Gene Y, we know that type 2 diabetes is one of the largest global diseases, so it's clear that there's still huge unmet need in that space. Right? I showed you figures which demonstrate that almost half of patients are not achieving target HbA1c. Many go on to require supplemental insulin.
The mechanism of Gene Y is that it's gonna improve insulin sensitivity, which is really central to glucose control. We have this preliminary evidence showing that this is achieved without weight gain, which can be an issue with insulin. I think we would be just really excited to expand the treatment options available for diabetes patients because there's clear unmet need in that space.
Weinong, you have any comment on that space again and how we're thinking about it overall?
Yeah, I think, you know, in terms of the Type 2 diabetes market, it is gigantic, with millions of patients with Type 2 diabetes. Although there is various variety of the armamentarium, but as Aimee commented, more than 50% of the patients lack the, you know, glucose control with HbA1c above 7%. Also very similar to the, you know, hypertension, this, you know, these patients are also suffer from the, you know, low adherence and compliance. We think, you know, with the SI/NI approach, with tiny control of some of the target gene expressions, we feel there is an unmet medical need we can address through those novel targets and potentially use it in combination with the current standard care.
Great. Anything to add there, Akshay or shall I move to the next couple of questions? We're cutting close on time.
I mean, I would just add that INHBE looks to be a very exciting target. I think, Aimee Deaton, your paper this year illustrated very nicely with human data the reductions in, you know, the improvement in glucose homeostasis in these individuals without INHBE loss-of-function, the improvement in the lipid profiles, the improvement in blood pressures. All of that suggesting, and with larger sample sizes, I'm sure this issue will be elaborated further, but all of that adding up to reductions in major cardiovascular events and so forth.
you know, I think, it's a really, really exciting target and one that, you know, in contrast to current approaches like the GLP-1 agonist, which can reduce body mass by reducing both adipose tissue and muscle mass, here's an opportunity to reduce, you know, adipose tissue alone and exert these beneficial effects. I find it a fascinating target, and one that could really create a very differentiated and important product profile for a large number of patients.
Thanks, Akshay. I'll also answer the one final question on that. There was a question about whether this is, whether Activin E is Alnylam fully owned or whether it's partnered with Regeneron. The answer is that this is a fully owned Alnylam program. We have a certain number of programs within Regeneron, but we also develop a bunch of our programs outside of that relationship. I'm gonna turn, you know, very quickly to some, you know, question around, you know, news that's out there now around that. I think this morning there was a company had shown some delivery to muscle, with an RNAi approach.
I'm gonna turn this one over to Vasant to talk a little bit about how we think about, you know, our approach to delivering to muscle and our early data, and really, what are the characteristics that we're looking for in a delivery solution.
Yeah. Thank you, Kevin. Yeah, I really, I believe released some of this data this morning today, or recently. I mean, we look at this one as a positive news. It just shows how robust and validated the RNAi technology is that you can go into these different tissues. We believe this data is with the antibody siRNA conjugates. In our case, we are not limiting ourselves to the ligands of specific type. We're going all the way from small molecules to cyclic peptides to nanobodies to antibodies. We'll try to find the best possible molecule for safety, for efficacy, for CMC in terms of its development and for commercial considerations.
With all that together, we're trying to find the best solution that gives us the potency and the safety to reach to the muscle tissue of the targets of interest and improve upon what is reported.
Thanks, Vasant. It looks like we're out of time. I wanna thank everybody. With that, I'm gonna turn it over to Akshay to close.
Yeah. Thanks, Kevin. In closing, I just wanna say I hope everyone's enjoyed this wonderful morning of science and medicine. You know, we've talked about our TTR franchise with tremendous progress with APOLLO -B this year and much more to look forward to with the submission of the sNDA, and of course, HELIOS -B fully enrolled. zilebesiran, some very interesting new data. I thought Dion had a very elegant sort of discussion about the differentiation that zilebesiran offers patients and how truly transformative that drug could be in a major global disorder. We've discussed the early- and mid-stage pipeline, which continue to fuel our growth, as well as the powerful advances from the platform that Aimee and Vasant discussed.
I think, you can rely on us to continue our journey to new targets and tissues, not just for the liver and the central nervous system, but, you know, important genetically validated targets in tissues like muscle and heart, adipose tissue, lung, kidney, and we're actively working on all of those. I think some very provocative data by Vasant today. 2023 looks very bright. There's a full year of work ahead of us. We look forward to achieving those goals. Thank you for your attention today, and happy holidays. Bye-bye, everybody.
Happy holidays. Bye.
Bye.
Bye. Happy holidays.
Bye-bye.