Hello everyone. I am Wa'el Hashad. I'm the President and CEO of Longeveron, and I would like to welcome you to Longeveron Key Opinion Leader events on hypoplastic left heart syndrome . Today, we are joined by three esteemed cardiothoracic surgeons, specialized in pediatric cardiothoracic surgeries, as well as HLHS or hypoplastic left heart syndrome . Before I start, I would like to just remind everyone that certain statements in the presentation today that are not historical in fact and are forward-looking statements made pursuant to the Safe Harbor provision of the Private Securities Litigation Reform Act of 1995. These statements reflects management's or the other presenters' current expectation and assumption, and involve uncertainties that could cause results to differ materially from those inferred or made in the presentation today.
For more detailed and specific, detailed information around our forward-looking statement, please review it in the slide here, as well as it's available on our website. Let me start by giving you a little bit of an overview about Longeveron. We are a leader in the development of mesenchymal stem cells, also known as medicinal signaling cells for therapeutic indications. We develop a well-characterized allogeneic MSC called Lomecel-B. This product, Lomecel-B, is currently in study in Phase 2 trials in multiple indications. These multiple indications include the disease that we're discussing today, which is hypoplastic left heart syndrome , and we're also studying the Lomecel-B in Alzheimer's disease and aging-related frailty. Longeveron have a proven management team, and we continue to strengthen that one, and we have a proven scientific and manufacturing teams.
We have a solid balance sheet and cash into the second quarter of 2024. One thing that is very unique with Longeveron, that we have our on-site GMP facility for the production of Lomecel-B, and therefore, we are not dependent on any contract development or manufacturing organization. Let me tell you a little bit about our three indications that we are pursuing. The one that we're discussing today is hypoplastic left heart syndrome . We have concluded our phase one study, and we have actually did a long-term follow-up for these patients and continue to do. Once we concluded the open-label phase one study, which had 10 patients, we were able to obtain an Orphan Drug Designation from the FDA.
We also were able to obtain a Fast Track designation from the FDA, which allow us to a faster and open communication with the agency. Finally, we were able also to obtain a Rare Pediatric Disease Designation that come with also a Priority Review Voucher. We are currently conducting phase 2 study, it's called ELPIS II , and this study will have 38 patients, and it is a head-to-head versus a standard of care. In the aging-related frailty, we have an ongoing phase 2A study in Japan. It is a 45-patient study, and we are looking forward to finish enrollment of this study in 2024, and after monitoring the patient, we'll announce the results from that study. The last indication that we're pursuing is Alzheimer's disease. We fully enrolled that trial.
That has 48 patients, and we expect to announce results from that trial at early Q4 of this year. This is just to show you where we are in the various programs that we are studying with Lomecel-B. As you can see, that we are all in phase 2, and aging-related frailty. We have concluded the phase 2 in the US, and we are conducting the phase 2 in Japan. As I mentioned, we have a very experienced management team. Other than myself, Dr. Hare, who you'll hear from him today, or you will hear from him today.
He is the co-founder of Longeveron, and he is the founding director of the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine, and he spent a significant part of his career at Johns Hopkins, and he is trained at Brigham and Mass General in Boston. We have also recently joined by Lisa Locklear, who is our Executive Vice President and Chief Financial Officer. She brings a significant experience and CFO experience both in the healthcare side. She was the CFO at Avanir Pharmaceuticals, and before that, she spent time at The Walt Disney Company and PwC. We have also Dr. Nataliya Agafonova, who joined us recently as the Chief Medical Officer. She brings an extensive expertise and capabilities in clinical development.
She has spent and made significant contribution at various roles in other companies such as Amgen, Bristol Myers Squibb, Celgene, Receptos, Juno, and others. She is expert in drug development and safety, and we're glad that she was able to join us. Last but not least, we have also Paul Lehr, who's our General Counsel and Corporate Secretary. He brings a significant legal expertise to the organization. He's also the former founder and CEO of Heart Genomics, a biotech firm that was based on an intellectual property license from University of Miami Miller School of Medicine. Hopefully, today you're gonna get excited about the discussions around HLHS. For us, it has been a busy year in 2023.
We have presented or published our data from our phase 1 ELPIS study in HLHS in the European Heart Journal. We also had our first patient enrolled in the Japan Phase 2 aging-related frailty trial. In May of this year, we have presented a long-term survival data from our p hase 1 ELPIS trial, which we were very excited about. As I mentioned when I reviewed the Alzheimer, that we expect the results from the Phase 2A trial to be early fourth quarter of this year. Stay tuned for that. With that, I'm gonna pass it on to Dr. Ram Subramanyan , but if you have any question, feel free to reach us at longeveron.com or through our investor relation group at LifeSci Advisors. Thank you.
Our next speaker is Dr. Ram Subramanyan , Chief of the Cardiothoracic Surgery Division and Assistant Professor of Surgery and Pediatrics.
Thank you for giving me this opportunity to discuss hypoplastic left heart syndrome . My name is Ram Kumar Subramanyan, and I am the Chief, Division of Pediatric Cardiothoracic Surgery at Children's Hospital & Medical Center in Omaha, Nebraska. This is gonna be the story of hypoplastic left heart syndrome . I'm primarily gonna concentrate on the clinical aspects, the approach to surgical palliation, and some of the expected outcomes. I have no relevant financial conflicts to disclose. hypoplastic left heart syndrome , or HLHS, is amongst the most complex congenital heart defects. Roughly 1,000 children are born with this condition every year in the United States. The disease is usually sporadic in origin. That means it doesn't necessarily run in families. It happens randomly. It is such a complex heart defect, such that there is 100% mortality.
No child survives without surgical and medical intervention. Over the past 25 years, we've made substantial progress in the surgical management of this condition, I'm gonna go through that over the next few slides. This has led to converting a disease that is essentially completely fatal to one that offers a lot of hope for the children with this condition. Our goal is to continue to push the envelope so we can offer novel therapies for these children with hypoplastic left heart syndrome . Here is a cartoon depiction of the anatomic defect in hypoplastic left heart syndrome . In the normal heart, the right side of the heart pumps blood without oxygen to the lungs. The blood picks up oxygen in the lungs and returns to the left side of the heart, and the left side of the heart pumps that blood to the body.
In children with hypoplastic left heart syndrome , this entire left side of the heart is not well developed. The valves, which are the doors that control the entry and exit of the blood, are underdeveloped. The entire ventricular cavity and muscle are not well developed, the tube, or the aorta, that carries the blood to the body is also very small and incapable of delivering enough blood to the body. That's the anatomic defect. Over the past less than a decade, we've also understood that HLHS results from molecular defects. That is, there are certain genes that are abnormal and potentially causative in HLHS. There are molecular derangements that may help us understand why children develop hypoplastic left heart syndrome .
One of the most intriguing aspects of this is that children with hypoplastic left heart syndrome may have heart muscle that is innately not capable of multiplying by itself and requires an additional external stimulus to get it to multiply and become stronger over time. These are all important as we discuss some novel therapies available for children with HLHS. Right now, for a child with HLHS, our palliation strategy involves staged surgical procedures such that pumping of the blood to the body, or what we call systemic circulation, is done by the heart. Remember, the only heart chamber that's developed is the right ventricle, which is originally intended to pump blood to the lungs, but in this case, we're gonna let the blood mix within the heart and make this right ventricle pump blood to the body.
Blood to the lungs, or pulmonary circulation, will change with the three stages of surgery. Early after birth, when the pressure and the resistance in the lungs is high, we use pulsatile blood flow, blood that's pushed into the lungs. Over the next two surgeries, as the lung remodels, we transition to directly connecting the venous blood to the lung circulation, and let's see how we do that. This is the first stage of palliation. This is called the Norwood procedure. This is usually undertaken in children when they are a newborn, within the first few days of being born. This is a very involved and intricate operation that eventually results in this picture we see here, where all the blood that's coming out of the heart gets pumped directly to the body.
We use an additional plastic tube that either comes from this artery to the lungs or directly from the heart to the lungs, but a new artificial plastic tube, which takes blood for lung circulation. It's a very complex operation. It's associated nationally with about 10-15% mortality and substantial complication risk, such that children have to spend, at a minimum, 4-6 weeks in the hospital before they're able to be discharged with this condition. Just because they are discharged, it doesn't mean that they're out of danger. This stage between the first and second surgery is associated with very high mortality.
Most centers have a formal interstage management protocol, where we routinely see these children to monitor their weight gain, to make sure there's enough oxygen in their body, to bring them back and see them in the clinic every one to two weeks, keep them on a very short leash, so to say, to make sure that they continue to progress the way we want them to, because roughly at about six to eight months of age, we're ready to proceed with the second stage of palliation. We're really good at giving surgery names, so we call the second surgery the Glenn procedure. At this time, as you can see, we get rid of that plastic tube. Instead, we connect the blood that comes back from the head and shoulders directly to the lungs. They were initially going to the heart.
They're disconnected from the heart and connected directly to the lungs. This is a very stable physiology. The oxygen levels come up to the 80%, 90% when children have this operation, and they can go home and grow well, because in this condition, there is blood separately going to the lung and blood separately going to the heart. This is actually a very safe situation for the child to grow. After this operation, we sort of release the children a little bit, allow them to be a child, grow up, do normal things, understanding that there will be some complications, like it's mentioned here, occasional headaches or some bluish discoloration around the lips, especially when the pressure in the lungs goes up. Roughly at about 2-4 years of age, they undergo the last stage operation that's called the Fontan procedure.
In this procedure, what we do is we take the blood that is coming from the lower half of the body, disconnect it from the heart, and connect it, usually with the help of a tube, directly to the lungs. Now, as you can see in this picture, blood from the top and the bottom half of the body go directly to the lungs, bypassing the heart. That blood gets oxygenated from the lungs and comes back to the left side of the heart and then gets pumped by the heart, one chamber now, to the body. We've separated the blood that does not and does have oxygen, so the oxygen levels immediately comes up to near normal. The important point to understand is, even though we're able to palliate with these three operations, it's a palliation, it is not a cure.
Fontan circulation is not the normal circulation. There is no current means to build a left ventricle that can separately pump blood to the body. Following a Fontan circulation, there are a reasonable number of adult survivors. They have acceptable neurologic and physical outcomes. Yet, despite such an amazing improvement in palliation, long-term failure is still observed in these patients with Fontan physiology. Some of the long-term failures are primarily related to the heart. The heart muscle, the right ventricle, is not intended to pump blood to the body. It was built to pump blood to the lungs that are right next to it. Asking it to pump blood to the entire body leads to heart failure, rhythm issues, or valve leak problems. These are all heart-related problems. There are non-heart related or Fontan circulation problems that are listed here that in addition, cause long-term morbidity and sometimes mortality.
These patients eventually may even become late heart transplant candidates if their heart continues to fail. As we've seen in this landmark publication that looked at follow-up of a cohort of patients who underwent these kinds of palliative operations, at about six years of age, less than two-thirds of the patient have a transplant-free survival. This is a very sobering statistic. Now, the positive way to look at this is 25 years ago, that number would not have been 62%. It would have been 0%. So we've come from 0 to 62. So now our question is: how can we go from 62 to 100? In addition, complications also begin early in life, and they steadily increase.
The need of the hour is to find new strategies that improve not just the long-term survival, but also overall outcome and outlook for patients with hypoplastic left heart syndrome . The Achilles heel, the biggest issue we have noticed in these children, is the lack of an appropriate systemic ventricle. Like I said, it's a right ventricle . It's inherently meant to pump to the lungs. It's an inherently not normal ventricle for systemic circulation, and therefore, function of the right ventricle is an important determinant of overall survival, as we saw in this paper as early as 2000, where really the qualitative function of the right ventricle was directly related to long-term survival in these children. Overall, my take-home is hypoplastic left heart syndrome is a complex heart defect. We've made significant headway in palliating the defect with medical and surgical maneuvers.
There's been substantial improvement in the immediate perioperative outcomes. Yet, opportunities exist to improve long-term outcomes in survivors from hospital stay. In that regard, there is the need for novel therapies that can impact the long-term function of the systemic right ventricle. I'm hoping that with all the efforts that are going in, these novel therapies will soon become a reality. Thank you for the opportunity, and I'm happy to take any questions.
Our next speaker is Dr. Sunjay Kaushal, Division Head of Cardiovascular-Thoracic Surgery and Professor of Surgery.
Thank you very much for allowing me to speak today. This is Sunjay Kaushal, the PI for the ELPIS study. I'm founder of Secretome Therapeutics using neonatal cardiac progenitor cells, although I'm not discussing this in this presentation. The main issue that we'll be talking today is RV dysfunction that occurs in single ventricle patients. We'll be discussing, in particular, hypoplastic left heart syndrome , as this is a type of condition that affects babies with congenital heart disease. Here on the left is a baby with normal function of the RV. It's beating well, contracting well. The tricuspid valve is working well. However, sometimes these patients don't do well. They develop RV dysfunction, where the RV is not contracting well. The RV becomes hypertrophied. There's tricuspid regurgitation. When this occurs, these patients don't do well, and they suffer from long-term outcomes as well as possible death.
We're trying to look at new interventions in order to prevent RV dysfunction. In particular, we're looking at using adult stem cells, stem cells that can be derived from adult patients to be used in pediatric patients. Adult stem cells have been used for many years in adult patients. It begins with a biopsy. The cells are isolated, ex vivo expanded, they're frozen, and then they're re-administered back to the patient in order to repair, remodel, or rejuvenate the, the dysfunctional organ. We're trying to use this same paradigm in pediatric patients now. In particular, we're looking at hypoplastic left heart syndrome . This is a condition that affects 1,000 cases per year, has 100% mortality without surgery.
It's one of the most complex congenital heart disease, high mortality with 35% in the first year of life due to suboptimal RV function. There's three independent operations that need to be performed. I would call these heroic operations that occur, where we're trying to reconnect and, and replumb, the heart in order for it to be more efficient. The Norwood operation occurs in the first week of life, the Glenn operation occurs at four to six months of life, and the Fontan operation occurs at three years of age. Despite this heroic surgical interventions, there's a associated mortality rate. When you look at transplant-free death and transplant occurrences, let's look at nine years. It's roughly around 57%. Even despite our great heroic surgeries, these patients don't do well long term, and so we're looking at different approaches, and it is an unmet need.
In particular, this is a study from the Columbia group that published that when patients look at survival rate in RV dysfunction, those patients that develop RV dysfunction, shown here, have very poor survival rate in comparison to the to the patients that do have normal RV function. Clearly, RV dysfunction is a very important attribute that leads to mortality. When you look at what happens to the myocardium in the response of pressure and volume overload, remember that there is no left ventricle. The right ventricle is pumping out systemically into the aorta. The adaptive response that occurs with this pressure and volume overload that is being required for the right ventricle is to preserve or increase the function in order, in order to compensate for that increased workload that's occurring. RV mass is maintained.
However, when there's a maladaptive response, there's decreased RV dysfunction, increased RV mass, and we're trying to ask the question whether stem cells can block this maladaptive response that's occurring to mitigate the decreased function that's occurring and preserve the RV mass. Stem cells is a great way of trying to mitigate this RV dysfunction. It can work through many pathways. Here is an example of some of the mechanisms of how stem cells could work. It can increase angiogenesis, decrease apoptosis, they immune evade, they immune modulate. They also are anti-fibrotic. They hit many pathways that can stimulate regeneration or remodeling of the myocardium. There has been studies that looked at stem cells in hypoplastic left heart patients, in particular, single ventricle patients. Two studies have been performed in Japan.
The TICAP trial has demonstrated in a phase I that it's safe and efficacious using autologous cardiosphere-derived cells, so cells that are derived from the heart itself, in young patients. The ones that are the youngest had the greatest change in ejection fraction compared to the ones that are older, which have a very small change in ejection fraction. Once again, showed the safety and feasibility. They followed this up with the PERSEUS trial, which is a phase 2 study, where they demonstrated that the patients that did receive the cardiosphere-derived cells improved their RV function by 6% in comparison to the control group, which did not improve. This was at baseline to 3 months.
They had a crossover, where they took the ones with the control group and gave them the cells, and then asked the question: Were you able to rescue? Again, you showed that they did. This is the 1st trial that really demonstrated that stem cells can improve the RV function of these patients. Another approach is using umbilical cord blood. The Mayo Clinic is using these cells in a similar type of design, where they're trying to ask the question whether these autologous umbilical cord blood cells can improve the function of the RV. The early results from the phase 1 has demonstrated the safety and feasibility, and they have not disclosed their phase 2's results yet.
With this set of data, we embarked on asking the question whether allogeneic mesenchymal stem cells can be used in hypoplastic left heart patients, and what is the mechanism of how these are working? In order to begin these studies, we created an acute porcine right ventricular model, which resembled many of the features of hypoplastic left heart , not all, but some. What you do in this model is that you take a pig's heart, and you band the pulmonary artery. What happens over time, within 4 weeks, this RV becomes dysfunctional. It's not able to sustain the circulation, and it dilates up and becomes dysfunctional. This is a very nice acute model that can study whether stem cells can work. We decided to use this model to ask that question.
We took allogeneic human mesenchymal stem cells , and we injected this directly into the myocardium of these pigs, and then asked the question: What happens to this RV over time? This is the design of the study. We use Yorkshire swine, 6-9 kilogram pigs. We had a placebo arm and a mesenchymal stem cell arm. We banded, and then 30 minutes later, we injected the cells into the RV, and then we had different measurements of performance by looking at echo as well as histology. Here are some of the improvements that occurred by echocardiogram. Here in all of these slides, the blue is placebo, and the red is the group that had mesenchymal stem cells . Let's focus in on the 4 weeks in each of these categories.
When you looked at RV fractional area change, there was improvement with mesenchymal stem cells compared to placebo. There was a decrease in RV end-systolic area , and an improvement, and also a decrease in RV end-diastolic area also. When you look at global longitudinal strain at four weeks, there was an improvement as well as strain rate. Those are independent values of RV loading. In summary then, there was a strong performance of the RV that improved with mesenchymal stem cell treatment, almost to the baseline that in these patients. We then looked at the myocardial structure. What was happening at the, at the micro level? What was happening at, at the cardiomyocyte level in these, in these, hearts?
What we noticed was that there was a decrease of fibrosis that was occurring with the mesenchymal stem cell group. There's increasing neovascular formation, arterial formation, and increase in cardiomyocytes cy- cycling, as well as endothelial cell cycling. Clearly, there was a remodeling effect that correlated with the RV functional performance that that had been demonstrated by echo. We went one step further. We wanted to understand the mechanism, how these mesenchymal stems were working. We noticed that when you looked at the RV free wall thickness in the MSC treated, there was a decrease in the wall thickness. That's kind of interesting. That's kind of not intuitive, and that's not what we expected. When we looked at the, at the microscopic level, what was happening with the cardiomyocytes? Were they being hypertrophy?
We looked at the cardiomyocyte cross-sectional area, we noticed that there was a decrease, which correlated with the echo results. We went on to demonstrate what was happening at the gene level, and there was a decrease in BMP, myosin light chain, and beta-myosin heavy chain. A switch of a gene profile was also occurring. We also looked at a potential pathway that was actually being changed with the stem cell therapy, and we noticed that GDF15 pathway was being upregulated by the stem cell treatment, which correlated with the downstream effects of SMAD2/3. What is GDF15? Well, GDF15 is a very important anti-hypertrophy pathway. It blocks hypertrophy response. What we're thinking is happening is that the mesenchymal stem cells are remodeling the myocardium at the microscopic level through a potential GDF15 pathway.
If you block hypertrophy, you can actually preserve the function of the right ventricle. Remember in that original cartoon, that when you have a maladaptive response, you want to block it with the stem cells in order to create the adaptive response, which is not hypertrophy. That is, I think, may be occurring with mesenchymal stem cell treatment. We were very excited about these results, and we took these results, as well as others, we took it to the FDA, and we got approval for a phase 1 study with Longeveron, using Lomecel-B in patients with hypoplastic left heart syndrome . The primary endpoints are listed here, were safety and feasibility, and the secondary endpoints was looking at the efficacy of these cells in these patients. Here's the design of the study.
We let these patients be born, carry through their first operation, and then at 3 months, we got a baseline MRI to understand the right ventricle, and then we had these patients undergo the stage 2 operation, the Glenn procedure, and we injected this cells into their right ventricle, similar to what we did in the preclinical model. We asked the question, "What was happening to the RV?" by looking at MRI at 6 months and also at 12 months. Here is a depiction of all the patients that have been enrolled in this phase 1. We had a run-in phase of 4 patients, and then we completed this with an enrolled phase 1 study of 10 patients.
Here's some pictures of the intraoperative of our first patient being injected with the mesenchymal stem cells , and we injected eight different sites into the RV. The inclusion/exclusion criteria is shown here. We had strict criteria. All of these patients had hypoplastic left heart . Here is a depiction of the baseline demographics of our Lomecel-B group, as well as our allogeneic mesenchymal stem cel l group and our total cohort of 14 patients. There's no big variations between each group. The operative variables are shown here. All patients had the injection. The average time was about 5.5 minutes, so not terrible. 600 microliters, an average of eight sites were injected into the right ventricular free wall, and the hospitalization was about 11.7.
I should mention that these injections occurred when the patients were still on bypass. So you want to have a very low injection time, which was what we achieved. The safety endpoints were achieved. There was no major adverse cardiac events. The comorbidities were low and not associated with stem cell delivery. We looked at secondary endpoints. Once again, we looked at by MRI, looking at baseline, 6 months and 12 months. We saw that there was a decrease in RV ventricular ejection fraction that occurred over time but was not significant. We looked at other parameters also, which were not significant in trend. When you look at tricuspid regurgitation, however, we noticed that there was a difference. Here is looking at tricuspid regurgitation by subjective measures, baseline, 6 months and 12 months.
As you can see, most of them moved from moderate to mild. When you quantitate it by looking at tricuspid regurgitation fraction, you notice that, in fact, these patients improved their ejection fraction , as shown here in this graph here, with a decrease in regurgitation fraction. We think that maybe that these cells are actually triggering a remodeling occurrence in the RV that's causing a decrease in tricuspid regurgitation fraction. Other secondary endpoints, we looked at BNP. When you look at BNP change from baseline, there was a trend for decrease, but not significant. Importantly, these allogeneic mesenchymal stem cells, these cells were derived from a young donor, did not stir up an immune response in these babies. That was demonstrated by looking at HLA class I.
In fact, the HLA class I decreased significantly with stem cell treatment over the six months. The HLA class II antibodies did not increase, but also decreased, which was not significant, but demonstrated a trend. We also tried to understand more at the mechanistic level, what was happening. So we took a advantage of a biological cue that happens or functional event that occurs when you inject mesenchymal stem cells into the heart. When you do that, these cells actually secrete exosomes, which are small, little balls of information that is, that's, that is from these cells, that can influence the myocardial cells, the cardiomyocytes, the endothelial cells. These microbubbles, we call exosomes, can also be detected in the blood. We've demonstrated it in preclinical models.
This is the first study that tried to understand whether we can actually detect these exosomes in these human patients as a liquid biopsy of how the cells are working in the heart. The way we do that is we take a very small quantity of blood from these little babies, and then we isolate exosomes from these samples of blood, and then we look to see what's in their cargo in order to determine how these cells are working in the heart. This is a depiction of the design of what we looked at. We isolated the plasma at day two and day seven. We looked at their exosomes. We isolated those out. We did a microarray analysis, and then we did some modeling based on some of the preclinical studies that we have done before.
We tried to correlate what was happening in those microbubbles RNA, correlating that with the functional improvement that we saw with tricuspid valve regurgitation. Here's some of the data. We first looked at the exosomes in two different patients. This is a highlight of what we did with this cohort. In pre, in these figures, blue is all exosomes, and red is specifically to the exosomes that are coming from the mesenchymal stem cells. We can isolate specific exosomes based on HLA mismatch. As you can see, when you have pre, so before the stem cells ejection, there's no red or very little red. Day two and day seven, there's an increase in red appearance.
That means there's more exosomes derived from the cells that were injected into the heart. This is the quantity of those. You can see that there is a decrease, but they're still present at day 7. What we did is we took those bubbles of information in those exosomes. We isolated out the RNA as well, the microRNA. We tried to understand more of what was happening. Here's some fancy plots looking at the microRNA and the mRNA at day 2 and day 7. They definitely exist. We did this principal component analysis, which really gives us a depiction of what is happening with these microRNAs and RNAs, showing that there is a difference at day 2 and day 7.
There's some patients that did not really have a change in RNA, and that's shown here as an example. There was not much difference from day 2 to day 7. Some patients, and most of the majority of patients, did have a change of their profiling that was occurring from day 2 to day 7, meaning that there was a change that was occurring at the molecular level in the myocardium by these cells. We did some fancy modeling. I'm not gonna go into those details. That's shown in E, and there was a correlation between tricuspid valve fractional change as well as RNAs, microRNAs that were changed in this in these patients. 54 were identified. Here's the top 10 which influenced it and top 10 that had negative impact.
We did biological process pathway analysis of 54 microRNAs and RNAs. What we noticed was that there was a significant enrichment of terms in, of negative regulation of stress-activated, mitogen-activated protein kinase cascade, so clearly a pathway. There was regulation of substrate adhesion and negative regulation of cellular metabolic processes. Of course, this will need further analysis to determine what was the key pathways in this. In conclusion, intramyocardial injection of allogeneic MSCs are both safe and feasible in hypoplastic left heart babies. There's initial signs of favorable effect on RV performance. The circulating donor MSC-specific exosome profiles may provide an insight in bioactivity, and this is the first time that a human liquid biopsy can now be determined for stem cell-based therapies. The challenges from this phase 1 is that it's low sample.
We're looking ahead to the ELPIS phase 2b trial to demonstrate the MSC efficacy for RV failure. Well, thank you very much for allowing me to speak about this exciting field, and I'll take questions now.
Our next speaker is Dr. Joshua Hare, Co-founder and Chief Scientific Officer of Longeveron.
Hello, my name is Dr. Joshua Hare. Today, I want to talk to you about Lomecel-B in the cardiovascular system. I'm the scientific co-founder of Longeveron and serve as its Chief Science Officer. I'd like to share these disclosures. I'm a co-founder and equity owner in Longeveron. I'm an inventor of technologies licensed from the University of Miami to Longeveron, and the University of Miami is an equity owner in Longeveron, which has licensed intellectual property from the University of Miami. I'd like to share this forward-looking statement, which I will not read. Today, I'd like to cover four topics. They are as follows: What is Lomecel-B, and how does Longeveron make it? What are the potential mechanisms of action of Lomecel-B? What is hypoplastic left heart syndrome ? What are the current treatments and outcomes?
What do we know about cell-based therapy for the human heart that can give us insights into the potential impact Lomecel-B could have on patients with hypoplastic left heart syndrome ? Lomecel-B is a cell-based medicine. It is produced from tissue from human donors and amplified in cell culture, where it can be frozen and used as a medicine. It's part of a class of medicines that have different names or a variety of names, and these names include mesenchymal stem cells , mesenchymal stromal cells, or medicinal signaling cells.... Lomecel-B is Longeveron's proprietary formulation of this class of medicines. It is made from adult human bone marrow. The donors are rigorously screened.
They are selected for between the ages of 18 and 45 years of age, and if candidates pass the rigorous health screening and agree to participate, they are subjected to a bone marrow aspirate from their iliac crest, and that bone marrow is used as the source for MSC culture expansion in a GMP laboratory. Once the cells are produced in large quantity, they are frozen and therefore become a ready-to-infuse product that can be delivered in a frozen state to distant clinical sites. Typically, Lomecel-B can be administered in a number of ways, depending on the patient's underlying condition.
In many of the clinical trials Longeveron is conducting, the cells are administered by an IV infusion. For patients with the hypoplastic left heart syndrome , they are delivered directly into the heart at the time of cardiac surgery. I'll tell you more about that in an upcoming slide. Here are some of the features of Lomecel-B. First of all, it's an off-the-shelf cellular therapy or cellular medicine. Because it's an allogeneic preparation, it can be taken from different donors and safely given to different recipients. It can be prepared in advance and therefore is what we call off the shelf. Specific features of Lomecel-B, it's an allogeneic medicinal signaling cell formulation.
These cells have been used in various situations over many years, and we know that these cells are immunoevasive and immunoprivileged, which is what allows them to be given from one donor to a different recipient. Once they're infused into the body, they home to sites of inflammation or tissue damage and exert a variety of healing effects at that site. Because they can be produced in large batches and are off the shelf, that allows the advantage of, of having robust quality assurance processes that can ensure batch-to-batch consistency. And once a batch is prepared, as I've mentioned, it can be stored in a, in a frozen state. It can be cryogenically kept in that state long term and becomes very easy to ship around the world, prepare, and administer. Here again is the GMP procedure that I showed you in the previous slide.
Again, rigorously screened healthy donors, bone marrow aspiration, and then that material is used to prepare the quality-controlled product in the GMP laboratory. Moving on to the next topic, what are the potential mechanisms of action of Lomecel-B? These cells, similar cells have been studied, as I've said, for many years, and several mechanisms of action have been identified that we think are operative and very important potentially for Lomecel-B's activity. We do know that cells like Lomecel-B do not engraft in the human body. In other words, when the cells are administered, they don't stay around for long periods of time or differentiate. Rather, they have secondary effects or paracrine effects that can be characterized into four types of effects. One is the release of growth factors and cytokines that can have either endocrine activity or paracrine activity.
Two, the cells can form cell-cell interactions with host tissues and transmit material directly to those host tissues. Three, MSCs, and we know this to be the case for Lomecel-B as well, release exosomes, which are small microvascular extracellular vesicles that contain a large number of substances, mainly microRNAs and other proteins, that can serve as a vehicle for transmitting these microRNAs and proteins to remote distances in the body. The fourth mechanism is called the nanotube bridge, which allows Lomecel-B to transmit mitochondria and other organelles directly into host tissues. This mitochondrial transfer can potentially replenish the host tissue's ability to make energy and therefore function in a better way. As I said before, Lomecel-B is a proprietary formulation of an allogeneic bone marrow-derived MSC, and MSC stands for, for a variety of different definitions based on who's using it.
Again, mesenchymal stem cell , mesenchymal stromal cell, or medicinal signaling cells. Now, the four mechanisms of action that I showed you on the left have four potential downstream activities that are important in treatment of diseases. Those four potential downstream activities are having a provascular effect, having an anti-inflammatory effect, having an anti-fibrotic effect, and stimulating intrinsic regeneration repair. These mechanisms have been well studied and shown in human situations, and I'm going to show you that data in upcoming slides. Not all of the well, not all of the studies that have shown these effects use the exact Lomecel-B formulation. Some of them use other MSC formulations, but we think that basically these mechanisms of action are operative for Lomecel-B as well as the other cells. Let's turn now to the hypoplastic left heart syndrome ....
A hypoplastic left heart syndrome , or HLHS for short, is a rare congenital heart defect in which the left side of the heart fails to develop normally. Children who are born with hypoplastic left hear t are desperately ill and are destined to die unless they can undergo three staged open heart surgeries. These surgeries are critical to reconfigure the heart so that the right side of the heart can be asked to do the job of the left side of the heart. In other words, we're shifting the flow of blood from the right side to the left side of the body. These procedures are called the Norwood procedure, which has to be done in approximately the first week of life, the Glenn procedure, which has to be done at four months of life, and then the Fontan, which is done at three to four years.
The Norwood is critical because the Norwood procedure shifts the flow of blood of the right ventricle, where it's going normally into the pulmonary circuit, so that it's pumped out of the aorta and to the body. The subsequent operations, the Glenn and the Fontan, now redirect the blood from the body directly into the lung, so that there's still blood flow to the lungs, so that the blood can become oxygenated, enter the right ventricle, and now oxygenated blood is being pumped to the body, which is critical for life. Now, there's a problem with this.
Even though these surgeries have been incredibly successful and have allowed these children who would otherwise absolutely die, to have a chance at life, even with the surgeries, a problem results, and that problem is the overload of the right ventricle. That right ventricle is not, it is not developed in a way that can allow it to withstand the pressures of pumping to the left side, which is a much higher pressure circuit, and that right ventricle fails, so that very few of these children live to adulthood. It's estimated that only, that overall survival to adolescence is estimated to be only 50%-60%. Again, this is an ultra-rare condition, and it's affecting about 1,000 babies a year in the United States.
This is an image from one of the patients whose heart was treated with Lomecel-B in our first study. This was called the ELPIS I study . You can see this is a CT scan, three-dimensional reconstruction. You can see that there's only a right ventricle, there's only a single ventricle, and it's pumping out of the aorta because this child has had the Norwood procedure. The blue arrows designate where the Lomecel-B has been injected into this baby's heart. What are the reasons for the right ventricular failure in hypoplastic left heart ? They can be divided into a variety of categories. The first is one I already mentioned, mechanical. The right ventricle is thinner and has a different shape from the left ventricle.
The forces imposed on the right ventricle when it is in the position pumping blood to the body, which we call the systemic position, are much greater than those intended for a native right ventricle. There's also a problem at the level of the myocytes, which are the specific cells that form the right ventricle. These right ventricular myocytes, again, are not developed to do the job of the left ventricle, and they're being asked to do so. In addition to the mechanical and cellular problems, there are also problems with the blood vessels. The heart has both tiny vessels and normal-sized vessels, and both of these microvascular and macrovascular vessels develop abnormalities.
We call these abnormalities endothelial dysfunction, and this can also contribute to the failure of the right ventricle because those vessels are critical in regulating the amount of blood that flows past the myocytes and provides it with the oxygen it needs to do its job. There are yet other abnormalities in the heart wall that contribute to the failure of the right ventricle and hypoplastic left heart , and these include inflammation and fibrosis, or scar tissue, that develop in the myocardial wall with all forms of heart failure, but specifically hypoplastic left heart , and this inflammation and fibrosis drives the progression of the disease.
We know from research with Lomecel-B and other types of MSCs, that these, this type of cell-based therapy approach can offset each of these categories of pathophysiology through its multifactorial mechanisms of action, and again, by exerting effects in those four downstream categories I talked about: pro-vascular, reduction of fibrosis, modulation of the immune system, and stimulation of endogenous repair. In the last few minutes of the talk, I'd like to go through data we have from studies with MSCs in the adult heart. These studies don't use Lomecel-B per se, but we think give very important insights in what Lomecel-B could do in hypoplastic left heart .
Prior to doing studies with Lomecel-B in hypoplastic left heart, there were many, many studies that were done in adults who have a variety of forms of heart failure. One of those forms of heart failure is called dilated cardiomyopathy. It's similar to hypoplastic heart in many ways because the ventricle in those patients fails and there are abnormalities in the myocytes. Now, what earlier studies have shown, and one in particular called the POSEIDON study, which is cited here, studied patients getting different forms of mesenchymal stem cells injected directly into the heart. These are adults now. What that study showed, the POSEIDON-DCM study, showed that the ejection fraction increased by 8 percentage points in the POSEIDON-DCM study.
In addition, there was a reduction in the right ventricular chamber size in the POSEIDON-DCM study, an effect which would be expected to reduce valve regurgitation, which is another beneficial effect in patients with heart failure. In that, that finding was that the end-diastolic long-axis diamete r decreased by 3.5 millimeters. In the ELPIS I study, the investigators who conducted that study showed that Lomecel-B maintained a measurement of the ventricle called global longitudinal strain over 1 year following the stage two surgery. We take that to be a very optimistic sign that Lomecel-B or cell-based therapy could be maintaining the structure and function of the hypoplastic left heart after the stage two surgery, and that's being tested in our ongoing study now.
Now, finally, when we talk about scar tissue in the heart, there have been quite a few studies that have been done in adults with MSCs that show that the amount of scar tissue in the adult human heart, in patients who've had heart attacks, can be reduced by the injection into the heart of mesenchymal stem cells . One study cited here showed that the amount of scar tissue in a myocardial infarction was reduced by 18.9%. Let me show you some examples from these adult studies. This is a patient who was in the POSEIDON-DCM study. This is an adult patient with dilated cardiomyopathy. You can see in the image on the left that the ejection fraction is very reduced at 19%, and the heart is very enlarged at 256 ml.
12 months after injection into the heart with mesenchymal stem cells, you could see the recovery. The ejection fraction has gone from 19 to 43%, and the heart size has been reduced from 256 to 192 ml, about a 60 ml reduction. This is a, this is a finding we refer to as reverse remodeling, and it's considered to be very important, and it represents one of the rationales for the use of testing Lomecel-B in patients with hypoplastic left heart . The investigators who conducted that study attributed that recovery in the ventricle to an immunomodulatory effect, and they inferred that by measuring the amount of tumor necrosis factor circulating in the patients' bodies. Again, this comes from the adult study, the POSEIDON-DCM study.
The TNF was measured in the bloodstream of those patients, and you could see in this image that the patients who received allogeneic MSCs, the off-the-shelf variety, had a 70% decline in their TNF, and that amount of decline was greater than patients who received MSCs from themselves or an autologous transplant, in which the reduction was only 50%. It's this kind of data that has spurred us on to test Lomecel-B in patients with hypoplastic left heart , because, as I mentioned, the inflammation in the heart is one of the drivers of the deterioration of the right ventricle in those patients. How about reduction of scar tissue in the human heart? This is an adult study, and we were able to measure the amount of scar tissue in these patients' heart by using an MR image.
The MRI is a very precise measurement because it allows us to image the scar tissue. You can see in this image that the scar tissue is coded a rose pink color, whereas the normal heart muscle is dark, dark gray. This patient, by example, received an injection of mesenchymal stem cells into the ventricle at the time of cardiac surgery. You could see the amazing reduction in scar tissue over an 18-month time frame. There were various manifestations of that reduction in scar tissue in the overall population. The circumferential length of the scar was reduced, as well as the scar thickness itself. Again, this is more data that suggests that cell-based therapy could be valuable in patients.
Again, this has provided a rationale for our studies of Lomecel-B in patients with hypoplastic left heart . Finally, I mentioned one of the features of MSCs is that they can stimulate endogenous repair. Again, this has been shown in other studies. Again, not Lomecel-B, but we infer that Lomecel-B could stimulate endogenous tissue repair based on findings from these two studies that I show you here. On the left is a study in Circulation Research in 2010, in which we measured the amount of division of cardiomyocytes and you could see that there's very nice evidence of the myocytes going through the cell cycle, as evidenced by these white stains here. That's a stain for the cell going through mitosis and dividing, and we saw an increase of cell cycle activity in this study.
This was actually an experimental study, not a human study, in subjects that were receiving a mesenchymal stem cell. The right panel is very exciting for us because it is a measurement of endothelial progenitor cells. These are cells that are released into the bloodstream from the body, from the bone marrow, and can re-heal the endothelial lining. I told you before that endothelial dysfunction's a very important feature of hypoplastic left heart , and this study, which was done in adults, published in 2015, showed that mesenchymal stem cell therapy could increase the abundance and the health of endothelial progenitor cells.
The investigators in that study did even more research and actually measured endothelial function by using an ultrasound test on the brachial artery in a human being's forearm, as shown here in the left panel, and then showing that the improvement in the EPCs actually correlated directly with the improvement in the endothelial function measured in the patient directly. We infer from this study that the Lomecel-B tests in patients with hypoplastic left heart could potentially improve the baby's outcome by exerting a variety of factors, all of the factors, in fact, that we attribute to mesenchymal stem cells in the human heart. To summarize what I've told you today, the effect of Lomecel-B on the cardiovascular system, again, with the caveat that some of these conclusions are drawn from studies that didn't use Lomecel-B directly.
We do infer that Lomecel-B has at least four potential reparative effects: one, stimulation of endogenous repair, two, neovascularization, three, immunomodulation, and four, reduction in fibrosis. Together, these effects have the potential to contribute to improved cardiovascular performance in children with hypoplastic left heart undergoing surgical repair. The majority of these effects are demonstrated in human studies, in studies performed in human adults, and using other variants of preparation of mesenchymal stem cells . Having said all of that, we are actively testing Lomecel-B in a study called the ELPIS II study, and we are testing the impact of Lomecel-B on right ventricular function and clinical outcomes in that study. I want to conclude here. Thank you for your attention.
At this time, we'll be conducting a question and answer session with our speakers. If you would like to submit a question, you may do so by using the Q&A text box at the bottom of the webcast player or by emailing your questions to questions@lifesciadvisors.com. If we run out of time on answering all the questions submitted, the Longeveron management team will follow up with you after the call. Our first question is: How practical is it to inject Lomecel-B during cardiac surgery?
I'll take that question. It's very practical. These patients are undergoing an operation already, we're not adding any expense of a, of a, of a procedure or an operation. These patients are undergoing the second operation of their palliative sequence, which is called the Glenn procedure. These operations occur between 4-6 months. During the operation, we have to use the bypass machine. The bypass machine does the work of both the heart and the lungs. These patients are on bypass in order to get the reconstruction of their surgery. Before coming off of bypass or separating from the bypass machine, we've been injecting these stem cells directly into the right ventricle. At that moment, the right ventricle is not performing function. It's actually very, very flaccid and just contracting at a very low rate.
Injecting the cells at that time, it seems the most logical and most safe way of administering these cells. We inject them into the right ventricle free wall, and what we notice is that there is no changes in hemodynamics after we've injected. This only takes about 5 minutes, the injection, so very little time, and then you separate from bypass, and then you can carry your standard routine post-operative management. The administration of these cells is very feasible. It's not adding another procedure or an operation, and it's only extending the bypass time by 5 minutes, which is inconsequential.
Great. With that, we'll move to our next question: Are there any safety concerns about injecting cells from a donor into babies with hypoplastic left heart syndrome ?
I'll take that question. So in our phase 1 studies, we were really concerned about the safety profile of these cells because this is the first time that these cells were being injected into little babies. We wanted to make sure, and we took a very close eye of looking at all the side effects and any serious effect that was occurring in these little babies. What we noticed is that, in fact, there was none. There was no side effects that we noticed that was being triggered by the cells themselves. In fact, one of the things that we were concerned about was whether there was a immune trigger by these cells. Were they stirring up the immune response because they're allogeneic?
We had never had tested that in a little baby, but we know that the little baby's immune response is not as robust as an adult, but we did not know what was, what was gonna happen. In our phase 1 studies, we looked at HLA class I, and we noticed that the class I was actually decreased significantly with administration of the cells. In class II, HLA was also decreased, but not, they had a trend for significance, but not significant. In summary then, these cells are extremely safe. We've not seen any side effects of the injection site, so meaning that there's no local edema or, or, swelling of the myocardium that triggers ventricular arrhythmias. We have not seen that. We've not seen any systemic effects of the cells being injected.
lastly, we've not seen any injury to coronary arteries which transverse that area that need to be avoided when you inject those cells. In summary, we've not seen any serious side effects of the mesenchymal stem cells when they're injected into the right ventricle.
Our next question is: What is the most encouraging finding from the ELPIS phase 1 study ?
I'll take that question. The, the most important study is, is... Or sorry, the, one of the most important endpoints is, is looking at RV performance, and you can look at it in, in many different ways. One way is to look at RV fractional area change or ejection fraction. That is a very good parameter, but may not be the parameter that we want to use in order to see if there's positive remodeling that's occurring. Far in our phase 1 results, we've noticed that tricuspid valve fraction, fractional change was actually decreased. Sorry, tricuspid valve regurgitant fraction was decreased, and I think that's very significant because that gives you a sign of early on that there was a remodeling occurring. There's a change in the morphology.
There's a change at the molecular level, potentially, in these patients with administration of the cells. That decreased tricuspid regurgitation. We know that in some patients, tricuspid regurgitation precedes right ventricular dysfunction, maybe we're stopping the early signs of RV dysfunction in those patients. That's a very, I think, a very key early sign. Of course, it needs to be validated in the phase 2, but gives an early sign that maybe these stem cells are working. The, I think the second important point here, or findings from our phase 1 study, is that we're now trying to understand at the molecular level what is happening. This is the first time that stem cell therapy has looked at the molecular level of how these cells are working within a organ that they're injected into.
We're doing that through looking at their exosomes, which are the circulating bubbles of information that's being secreted by the cells from the heart. You can interrogate those microbubbles or exosomes and understand how or what pathways the cells are triggering, because those exosomes is a signature of the mother cell, the cells which are in the heart. This may give us a, a insight of how these cells may be working in the heart. This gives us a, a potential way of looking at maybe some res- cells. Sorry, some patients may be good responders, some patients may not be good responders. This may give us a, a, a biopsy, a liquid biopsy of trying to understand which patients will be the best performers.
Of course, a lot more work needs to be done. We're looking forward to the phase 2 studies, which will give us further insight of how these cells are remodeling the myocardium. I think there is excitement over the early, early results of the phase 1 study.
Our next question is: How big is the need to improve clinical outcomes for children with HLHS?
Sure, I'll take that question. The clinical need is very significant. As I said, there is a mortality associated with each of the three operations that we do, such that, putting it very bluntly, less than two-thirds of the children with hypoplastic left heart syndrome reach kindergarten school age. That's a sobering statistic. I mean, I recognize that none of them did before surgery existed, but we're better than this. We're going to be able to do something to improve that number, such that every child is able to survive successfully despite hypoplastic left heart syndrome . Like some great man said, "We've won hypoplastic left heart syndrome when a child with HLHS that I treat outlives me." The economic burden is very significant.
These children spend a lot of their time in the hospital, it's estimated that in 2021, over $1 billion was spent a year just in caring for hypoplastic left heart syndrome , and this is direct cost. There is a significant indirect cost. There is loss of wages for the family members. There is quality of life issues for even the surviving children. Overall, in my opinion, the need to fill, to treat hypoplastic left heart syndrome is substantial, but something I'm very hopeful about.
This concludes our Q&A session. I would now like to hand the call over to Wa'el, CEO of Longeveron. Please go ahead, Wa'el.
Thank you. First, I wanted to thank our three speakers today, Dr. Subramanian, Dr. Kaushal, and Dr. Hare, for their insights into the management of hypoplastic left heart syndrome . I hope you found it exciting and informative, as I always get energized by these talks, so my gratitude to all of them for their time and their knowledge that they shared with us. For everybody, I hope that this presentation gets everyone excited about the work that we're doing here at Longeveron, as we all are here. Thank you very much, and have a-