Greetings, and welcome to Fulcrum Therapeutics' fourth quarter and full year 2022 earnings conference call. At this time, all participants are in a listen-only mode. A brief question and answer session will follow the formal presentation. If anyone should require operator assistance during the conference, please press star zero on your telephone keypad. As a reminder, this conference is being recorded. It is now my pleasure to introduce your host, Chris Calabrese. Thank you, Chris. You may begin.
Thank you. Good morning. Welcome to the Fulcrum Therapeutics fourth quarter and full year 2022 financial results and business update conference call. Please be reminded that remarks made during this call may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These may include statements about the company's future expectations and plans, including the clinical hold of FTX-6058, clinical development timelines and financial projections. While these forward-looking statements represent Fulcrum's views as of today, they should not be relied upon as representing the company's views in the future. Fulcrum may update these statements in the future, but is not taking on an obligation to do so. Please refer to Fulcrum's most recent filings with the Securities and Exchange Commission for a discussion of certain risks and uncertainties associated with the company's business.
Leading the call today will be Dr. Robert J. Gould, Interim Chief Executive Officer of Fulcrum, who will provide a corporate overview and will discuss key pipeline updates. Esther Rajavelu, Chief Financial Officer, who will cover the financials before we open the call for Q&A. Dr. Alan Ezekowitz, member of the Fulcrum Board of Directors, who will serve as a Senior Clinical Advisor, will be able to answer questions during the Q&A portion of the call. With that, it's my pleasure to turn the call over to Robert.
Thank you, Chris. Good morning. I appreciate everyone taking the time to join us today. We provided several important business updates this morning in our press release and 10-K, including additional color on the FTX-6058 full clinical hold, data from the now suspended 12 mg cohort of the phase 1-B sickle cell disease trial, updated guidance on our cash runway and changes to our management team. Let me start by discussing our most recent updates to the FTX-6058 program, our oral HbF inducer for the potential treatment of patients with sickle cell disease.
As we announced on February 24th, we received verbal notification from the FDA on February 23rd that they had placed a full clinical hold on the Investigational New Drug Application for FTX-6058. We received a formal clinical hold letter from the FDA on February 24th. We immediately suspended dosing and paused enrollment in the phase I-B trial. In its communication to us, the agency noted that the hold related to both preclinical data previously submitted in April, October, and December 2022 and non-clinical and clinical evidence of hematological malignancies observed with other inhibitors of the Polycomb Repressive Complex 2 or PRC2.
The agency specifically noted that the profile of hematologic malignancies observed in the non-clinical studies of FTX-6058 is similar to that observed with other inhibitors of PRC2, and that hematologic malignancies have been reported clinically with other PRC2 inhibitors. The agency requested that Fulcrum further define the population where the potential benefit of continued treatment with FTX-6058 outweighs potential risk. The hold was not a result of any clinical finding in the phase I-B trial that was ongoing at the time of the hold. Prior to the clinical hold, we had completed dosing at 6 mg dose and were completing dosing patients in the 2 mg dose cohort and were enrolling and dosing the 12 mg dose cohort.
In early January, we shared data from the completed 6 mg cohort with 10 patients that demonstrated up to 9.5% absolute HbF increases from baseline and similar treatment responses to FTX-6058 in subjects on and off background hydroxyurea. We also shared partial data from the ongoing 2 mg cohort in January. This morning, we provided an updated data set from the two patients that completed dosing in the 2 mg cohort and the now suspended 12 mg cohort in which we enrolled three patients. The 2 mg patients that completed 84 days of dosing achieved absolute HbF increases up to 4.6% through the end of treatment, suggesting 2 mg is a potentially minimally efficacious dose.
Data from a patient in our 12 mg cohort who completed 42 days of treatment demonstrated absolute HbF increases up to 10%, as well as improved biomarkers of hemolysis. A way of comparison, at this same early time point of 42 days, adherent patients at the 6 mg dose had an average increase in absolute HbF of 4.5%, while adherent patients at the 2 mg dose had an average increase in absolute HbF of less than 1%. These new data continue to support a significant reduction of HbF as well as a robust dose response effect. All three subjects at the 12 mg dose also had an increase in hemoglobin of at least one gram per deciliter at the 28 day study time point. With one subject achieving a 2 gram per deciliter increase by day 42.
We find these initial data to be highly encouraging and further supportive of the clinical potential of this drug. FTX-6058 has generally been well-tolerated to date, with no drug-related treatment emergent serious adverse events or discontinuations due to treatment emergent adverse events. All adherent subjects showed clinically relevant improvement in the 6 and 12-mg dose cohorts, consistent across subjects both on and off background hydroxyurea, which is the current standard of care. These clinical data give us great confidence that FTX-6058 has the potential to provide a differentiated therapeutic option for people living with sickle cell disease and a favorable benefit risk profile. We remain committed to 6058's further development and look forward to working closely with the FDA to address all outstanding concerns as rapidly as possible. We will provide an update once we have more clarity on the path forward.
For now, we are suspending our previous guidance to complete the phase I-B trial and our guidance to select a registration enabling dose in the fourth quarter of 2023. Turning to our most advanced program, losmapimod, a selective p38α/β mitogen-activated protein kinase inhibitor. Losmapimod is in phase III development for the treatment of FSHD. FSHD is an autosomal dominant genetic form of muscular dystrophy, which has an estimated patient population of 16,000-38,000 in the U.S. alone. It is characterized by progressive muscle death and fat infiltration and results in the inability to perform daily life activities due to a significant impairment of upper extremity function, loss of mobility, and chronic pain.
While it is one of the most common forms of muscular dystrophy, there are currently no approved treatments. We believe losmapimod has the potential to address the urgent need for a safe and effective disease-modifying treatment that can slow or stop disease progression. We initiated REACH, our double-blind, placebo-controlled phase III trial of losmapimod in June 2022. We are currently enrolling patients in the U.S., Canada, and Europe. The trial is expected to enroll approximately 230 adults. We are on track to complete enrollment in the second half of 2023. The primary endpoint is the absolute change from baseline in Reachable Workspace, or RWS, a quantitative measure of upper extremity range of motion and function that specifically evaluates shoulder and proximal arm mobility with 3D motion sensor technology.
Preserving this upper extremity function is critical for maintaining the ability for self-care and other activities of daily living that directly influence quality of life and independence. In addition to safety and tolerability, secondary endpoints include muscle fat infiltration, or MFI, an important marker of disease pathology, and self-reported outcomes such as the Patient Global Impression of Change, or PGIC, and quality-of-life measures. These will include healthcare utilization questionnaires that will inform our thinking about payer strategy as we prepare for a potential commercial launch. REACH was designed as a highly efficient 48-week trial and is intended to be registration enabling both in the US and in ex-US geographies. We are confident that we have selected reliable measures of disease progression, and we hope to demonstrate meaningful advantages for losmapimod compared to placebo.
Encouraging, our phase II-B ReDUX4 trial demonstrated significant improvement in RWS relative to placebo at 48 weeks. Furthermore, top-line results from the ongoing open label extension show that participants in the initial treatment arm who continue to receive losmapimod just demonstrated durability of effect through a 96-week period. Additionally, patients who crossed over from placebo to losmapimod after the initial 48-week trial period showed improvement in slowing of disease progression, as measured by RWS mean change from baseline. We believe these data support the disease-modifying potential and long-term benefit of losmapimod. To date, losmapimod has been dosed in over 3,600 patients across multiple therapeutic areas, and results from ReDUX4 and our open label extension trial provide evidence of an encouraging safety and tolerability profile.
We have reached alignment with regulators in the US and Europe on the primary endpoint for REACH, and as we drive our clinical path forward for losmapimod, we'll continue to leverage the large safety database and build on our learnings from ReDUX4 and ongoing open label extension trial. Now turning to other corporate matters, we announced this morning that Dr. Santiago Arroyo, our Chief Medical Officer who joined us in November 2022, resigned from the company late last week, effective March 7th, to pursue another opportunity. We are excited to appoint Dr. Iain Fraser as Interim CMO effective today. Dr. Fraser brings over two decades of experience in advancing therapies through early and late-stage development and possesses deep expertise in regulatory affairs. He most recently served as Vice President and Clinical Fellow at AlloVir, an ElevateBio company.
He previously held clinical development roles of increasing responsibility at Abide Therapeutics that was acquired by Lundbeck in 2019, and prior to that was part of the clinical development organization at Merck. In addition to Dr. Iain Fraser joining us, Dr. Alan Ezekowitz, member of the Fulcrum board of directors since February 2017, will serve as senior clinical advisor to ensure program continuity. With that, I will turn the call over to Esther Rajavelu to provide an update on our financials.
Thank you, Robert. I will first provide an update on our cash position and runway guidance and then review fourth quarter and full year 2022 financial results. We ended December 31, 2022, with cash equivalents, and marketable securities of $202.9 million, compared to $218.2 million in December 31, 2021. In January 2023, we strengthened our balance sheet and cash position following an underwritten public offering of 9.6 million shares of common stock at a public offering price of $13 per share. The gross proceeds from this offering were approximately $125 million before the deduction of underwriting discounts and other offering-related expenses and resulted in approximate net proceeds of $117 million to the company.
We continue to operate from a strong financial position with a pro forma cash balance of approximately $320 million and expect our cash equivalents, and marketable securities to fund our operating expenses into mid-2025, assuming a timely resolution of the FTX-6058 clinical hold. Turning to the fourth quarter and full year 2022 financials. Collaboration revenue was $0.7 million for the fourth quarter of 2022 and $6.3 million for the full year 2022, compared to $5.1 million for the fourth quarter of 2021 and $19.2 million for full year 2021. The decrease was primarily due to the previously announced termination of Fulcrum's collaboration agreement with Acceleron Pharma.
Total operating expenses were $28.7 million for the fourth quarter of 2022 and $118.9 million for the full year 2022, compared to $28.6 million for the fourth quarter of 2021 and $100.2 million for full year 2021. The increase was primarily due to increased employee-related costs, including increased stock-based compensation and increases in R&D, and including a $5 million milestone paid to GSK upon the initiation of the phase III REACH trial. Net loss was $26.1 million for the fourth quarter of 2022 and $109.9 million for full year 2022, compared to a net loss of $23.5 million for the fourth quarter of 2021 and $80.8 million for full year 2021. With that, I'll turn the call back to Robert for closing remarks.
Thank you, Esther. We remain focused on driving our clinical programs forward, exploring opportunities to leverage the value of our research engine, and executing on our corporate objectives. We remain on track to complete enrollment for our FSHD phase III REACH trial in the second half of this year and are committed to working with the FDA to resolve the clinical hold on FTX-6058. We will provide updates as communication with the FDA proceeds. I want to reiterate that we are optimistic there is a path forward to resolve the full clinical hold on FTX-6058. We are working diligently to enable FTX-6058's expeditious return to the clinic. Before we conclude today's call, I want to extend my sincere appreciation and gratitude for the foundational work that has brought us closer to treating the root cause of genetically defined rare diseases and bringing transformative therapies to patients.
I would like to thank the entire Fulcrum team, our investors, and the many people who have been supportive along the way, including our patients and their families. With that, we are happy to take questions. Operator?
Thank you. We will now be conducting a question and answer session. If you'd like to ask a question, please press star one on your telephone keypad. A confirmation tone will indicate your line is in the question queue. You may press star two if you'd like to remove your question from the queue. For participants using speaker equipment, it may be necessary to pick up your handset before pressing the star keys. One moment, please, while we poll for questions. We take our first question from the line of Matthew Harrison with Morgan Stanley. Please go ahead.
Great. Good morning. Thanks for taking the question. I guess two for me. First, are you expecting to request a Type A meeting with the FDA? Could you maybe just talk a little bit about, you know, what your current plan is given that you now have the full letter around handling the clinical hold? Secondly, I guess just specifically on the hematologic malignancies that you observed in the rat study, do you expect that you could potentially exclude certain patients from the clinical study to change the risk? Do you think, and I know it's very early, do you think a new toxicology study may be necessary? Thanks.
Thank you, Matt. Just taking your second question first, as we move forward in our dialogue with the FDA, they noted that they were really encouraging us or asking us to define a patient population that may benefit from the elevations in HbF. Therefore, address the benefit risk ratio. As you probably know, numerous other studies that have gone on in the sickle cell arena have defined higher risk patients that are at higher risk for things like VOCs. We're taking a close look at those studies. Our study was essentially an all-comer study in sickle cell patients. Moving forward, one of the things we're considering is what a higher risk population, sickle cell population would look like.
The clinical hold noted that the profile of malignancies observed in the study of 6058 was similar to that observed with other inhibitors of PRC2, and we believe that we can address all other questions with the data that we have in hand.
Thanks, Robert. Just to follow up, are you planning to request a Type A meeting or not? I don't know if you can-
Oh.
If you know that yet.
We're still working through exactly what our strategy is gonna be moving forward. Sorry about that. I meant to mention that. Certainly we've had the letter almost immediately after we had the call with them, which really gives us a jump start on putting that plan together, and we'll keep updating as the plan develops.
Great. Thank you very much.
Thank you. We take the next question from the line of Matthew Biegler with Oppenheimer. Please go ahead.
Hey, guys. Thanks for the question. What's the best comp here as it relates to cancer risk? Is it tazemetostat? That's an EZH2 inhibitor, but it also works on the PRC2 axis. It was recently approved in, I think, lymphoma. Is there a reason to think the cancer risk might be lower with your drug? 'Cause I think you're only reducing methylation by about 70%, whereas I think tazemetostat completely ablates it. I'm just kinda curious what your thoughts are there.
sely correct. So tazemetostat's approved in epithelioid sarcoma as well as relapse refractory follicular lymphoma, and that's therefore from the information that's been provided on tazemetostat. We have the most insight into what happens when you fully inhibit the PRC2 complex. In the label for tazemetostat, they noted neutropenia, thrombocytopenia, anemia as reasons for dose modification of tazemetostat. And I'd point out that in our healthy volunteer and our sickle cell population, we've not observed any of those effects. So we think there's a fundamental difference in the clinic in how FTX-6058 is interacting and affecting hematologic development versus how an EZH2 inhibitor like tazemetostat is affecting that. Does that, does that answer your question?
Yeah, that makes sense. I also... I wanted to follow up about the prior question about identifying a patient population with maybe the optimal risk to benefit. Do you foresee something like including only patients with higher baseline HbF? Just remind us, has there been a link between baseline HbF and HbF induction on drug yet? Thanks for the question.
Yeah. Before I let Alan address the higher-risk population, let me speak to the baseline question. We have not seen a relationship between higher baseline HbF and the degree of induction of HbF that we're seeing with FTX-6058. That is, we now have patients whose baselines range from about 4% HbF to about 20% HbF. Certainly in the 6-mg data, where we have the most patient experience, independent of where they start and independent of whether they are on hydroxyurea or not, we see similar increases of about 10% HbF. Alan, maybe you wanna speak to the higher-risk population question.
Yes. The all-comers study that we did, which was an open label study in phase I-B, we recognized that we need incidence because we need a baseline of VOC. Guided by some of our-- the studies that have been done with gene therapy and gene manipulation therapies, increasing the frequency of VOCs, as well as the seriousness of other complications like acute chest syndrome and other episodes are parts of the population that we would like to exclude. The strategy would be just like that. We would start with a high-risk population and then expand that out as we go along.
Okay. That makes sense. Thanks for the question.
Thank you. We take the next question from the line of Madhu Kumar with Goldman Sachs. Please go ahead.
Hi, guys. This is Rob on for Madhu. Thanks for taking our question. First, how does the PRC2 complex inhibition you observed compare to other PRC2 drugs used in cancer? What dose of FTX-6058 do you pre-clinically observe hematologic malignancy risk, and what does that translate to clinically?
As we've discussed previously, we're getting about 70% to 80% inhibition of the H3K27 trimethylation mark. Tazemetostat, where we have most insight into PRC2 inhibition, is getting 80% to 100%, and that appears to be the best differentiation that we can compare. We've not really discussed the degree of preclinical exposure related to the malignancies related to the clinical dose that we're using. But we're confident that we have the ability to define a benefit risk as we move forward in the sickle cell patients.
Thank you.
Thank you. We'll take the next question from the line of Judah Frommer with Credit Suisse. Please go ahead.
Yeah. Hi. Thanks for taking the question. Just following up on defining that benefit risk profile. Have you had further clarity from FDA on whether, you know, potentially gene editing programs are precedent for definition of that risk, or are they, are they more leaving it up to you? Is, is that what you're particularly working on if you feel the preclinical data set you have is sufficient currently?
Yeah. We've not had specific conversations, nor is there any indication from them that they're making that comparison. Certainly, the gene editing approaches have risk associated with them that they are discussing with the FDA. We think that provides clarity on how we can define a population that, in which the benefit is greater.
Okay. Is your sense that defining that population would be potentially a step into getting back to the broader sickle cell population or that you could be restricted to that?
Yeah.
you know, higher risk population?
It's a little early for us to know that yet because of course, that involves discussions with the FDA. Our current plan is to define what and discuss with the FDA what we think that higher risk population is. As Alan said, once we demonstrate what we think will demonstrate a beneficial benefit risk ratio in that higher risk population, it provides the opportunity for us to continue discussions on additional populations.
Okay. Thanks. Just lastly, just curious. We've seen some gene editing programs kinda drop out in sickle cell disease recently. Coincidental timing in your view? Could there be anything, you know, that maybe FDA communicated to those programs that might be related here? Maybe just more kinda general unmet need in sickle cell disease from FDA's perspective. Do you got any incremental insight on that, which seems still to be pretty large, but understandably, risk benefit needs to be defined.
I think unfortunately for sickle cell patients, it's coincidental that all this data came up at the same time. There's no indication in our correspondence that we received in the clinical hold letter that there was any read-through from the gene editing world.
Thanks.
Thank you. We'll take the next question from the line of Dagen with Stifel. Please go ahead.
Hey. Good morning. Thanks for taking the questions. I'll stick with the non-clinical observations, if I may. Can you go into a little bit more detail around what exactly were the observations and the duration at which point you observed this? There were a couple of, I guess, references earlier about tazemetostat, but that, I guess, label indicated about nine months before they saw that. When in your rat and potentially dogs, I believe the in-life portion is complete, have you seen that? Related to that going forward, I guess as you contemplate more non-clinical studies, what do you define as a bar for disclosure or materiality to disclose to the public? Thanks.
Thanks, Dagen. Just to remind you, we had done four, 13, 17, and 26 week studies in rats and four week, 13 week, and 39 week studies in dogs. We've just received the draft report on the 39 week study in the dogs. Certainly, much of that material was available to the FDA at the initial IND as well as provided in the updates that I referred to earlier in the script. We've not disclosed when during the course of those treatments the malignancies appeared, but certainly the FDA was comfortable with the healthy volunteer study as well as the initial sickle cell population.
We'll continue to provide updates as we have correspondence and dialogue with the FDA on how we define that benefit risk, and particularly, the plans and discussions with not only increasing the benefit side, but also, what they would and we would like to do to address the risk side.
Dagen, do you have any further questions?
No. Thank you very much.
Thank you. We'll take the next question from the line of Ted Tenthoff with Piper Sandler. Please go ahead.
Great. Thank you very much. I think we've extensively covered 6058, so, you know, just good luck on that. And I think it's important, you know, this drug could really differentiate with the broadest population possible, I think, if you're able to ultimately establish safety in that population. I'm looking forward to hearing more as this progresses. Looking at losmapimod, maybe just kinda remind us where you see this drug most appropriate. Is this a drug that would be broadly applied to, or, you know, again, I know we're working with Reachable Workspace as the primary endpoint, but where do you kinda see as the most appropriate patients, FSHD for that drug? Thanks, guys.
Thanks, Ted. Yeah, we do think this is a drug that has potential to be broadly applicable in the FSHD population. I remind you that the population, based on a white paper and voice of the patient, has repeatedly advocated for an agent that stabilizes the disease at the stage that they're at. It's a disease of adaptation, certainly with the Reachable Workspace results that we saw in the ReDUX4 study, we were able to stabilize patients where they were, and patients that were on placebo declined and then stabilized when they crossed over to the open label extension.
That trial took patients who were in, if you will, a broad patient population who were showing symptomology, but were not yet in a wheelchair, so in sort of two to four range of the clinical scale that's used in FSHD. That's where the bulk of the population lies. We think it's broadly applicable across a very broad patient population.
Great. Thank you. Excited for that data, you know, complete enrollment this year and that data hopefully next year. Thanks so much.
Yeah.
Thank you. We take the next question from the line of Joseph Schwartz with SVB Securities. Please go ahead.
Hi. Thank you. I was wondering, have you looked at the impact of FTX-6058 on erythroid maturation via flow cytometry on CD34 cultures to determine that it isn't inducing maturation arrest? A related question, have you done any red blood cell viscosity deformity morphology analyses on the patients treated so far? What about F-cell data in order to be confident that FTX is promoting the development of quality RBC?
Yeah. We have looked at the red cell differentiation, erythropoiesis and really don't see any effect. That's consistent with the correction of anemia that we're seeing in the patient population. Certainly, we didn't see any effect on erythroid maturation in in vitro or in vivo studies. One potential data that you might focus on is the reduction in the absolute reticulocyte count, that's consistent with ameliorating the anemia. There's no other evidence or an effect on the red cell differentiation. In terms of deformability of the red cell, what we've looked at is the RDW, the check the distribution width, which is a sort of a surrogate for deformability. As we showed at six and also as we're seeing at 12, we get normalization of those parameters.
That's consistent with preventing the sickling event from occurring. We're still analyzing the percent F cells. I'll remind you, in the preclinical studies, we saw all of the cells responding. That is, the percent F cells were pancellular or the raise in HbF was pancellular.
Okay, thanks. Will you be reporting any more data on the patients, particularly those at 12 on and off drug now?
Yeah. As we move forward and as we provided all the data we have as of, I forget the exact cutoff date, but we've provided all the data we have in hand currently, and we'll be considering how we provide updates on these patients moving forward. Certainly, there's still interest, and we're still following them.
Thank you.
Thank you. We'll take the next question from the line of Tazeen Ahmad with Bank of America. Please go ahead.
Hi. Good morning, and thank you for taking my questions. Robert, just to clarify maybe on timelines, if we could, do you think that if you're correct and that you think you'll be able to answer all the questions the agency has with data that's in-house, do you think that the clinical hold could be lifted in this calendar year, or could it be something that could take a while? Secondly, can you remind us of what next gen assets you have in-house, how you've quantified them so far, and what their profile might be in terms of differentiating on the safety side? Thank you.
Yeah. As we're still engaging in dialogue with the FDA, it's a little hard for me to predict how quickly the clinical hold will be lifted because, as you know, there's timing that we don't control. We're anticipating it'll be at least four to six months at the earliest. We have a number of other programs that in both the sickle cell as well as the muscular dystrophy states that are at the preclinical drug discovery stage. We'll be discussing those more in the future. As you probably recall, we do not anticipate filing another IND this year.
Would that, would the feedback from the FDA change that plan at all?
No.
Okay. Thank you.
Thank you. Ladies and gentlemen, we have reached the end of the question and answer session, and I would now like to turn the floor back over to Robert Gould for closing comments. Over to you, sir.
Well, thank you. Thank you very much to everyone for your time and attention, today. Please stay safe and healthy. This concludes today's call. Thank you.
Thank you very much. Ladies and gentlemen, this concludes today's teleconference. You may disconnect your lines at this time. Thank you for your participation.