Ladies and gentlemen, thank you for standing by, and welcome to the Solid Biosciences Strategic Business Update and Financial Results conference call. At this time, all participants are in a listen-only mode. Please be advised that today's conference may be recorded. After the presentation, there will be a question-and-answer session. To ask a question, please press star one on your telephone to get in the queue. I would now like to hand the conference over to Caitlin Lowie, Vice President of Communications and Investor Relations at Solid Biosciences. Ms. Lowie, you may begin. Good morning. Thank you, operator. Before we get started, I would like to remind everyone that during today's conference call, we may make forward-looking statements, including statements about the company's financial results, financial guidance, future business strategies and operations, and product development and regulatory progress, including statements about the company's IGNITE DMD clinical trial. Actual results could differ materially from those discussed in these forward-looking statements due to a number of important factors, including uncertainty inherent in the clinical development and regulatory process, the extent and duration of the impact of the COVID-19 pandemic and other risks described in the Risk Factors section of our most recently filed annual report on Form 10-K and other periodic reports filed with the SEC. We undertake no obligation to update any forward-looking statements after the date of this call. With me on today's call are Ilan Ganot, Co-founder, President, and Chief Executive Officer of Solid Biosciences, Dr. Joel Schneider, our Chief Operating Officer, Dr. Carl Morris, our Chief Scientific Officer, and Dr. Roxana Donisa Dreghici, Senior Vice President and Head of Clinical Development. During today's call, we will share details of the strategic update the company announced this morning. We'll begin with opening remarks from Ilan, followed by Joel, who will share details of an intended change we'll be making to the manufacturing approach for SGT-001. Carl will then review new pre-clinical data related to SGT-003. Finally, Ilan will provide an overview of the organizational strategy that aligns behind these two programs before opening the call to questions. Before I turn the call over to Ilan, I want to acknowledge that our first quarter financial results have been reported and can also be found on our Form 10-Q, which was filed with the SEC this morning. For opening remarks, I'd like to turn the call over to Solid Biosciences' CEO, Ilan Ganot. Ilan? Thank you, Caitlin, and thanks to all of you for joining us this morning. Solid's ongoing focus on Duchenne has produced two potential therapies for this devastating disease. Today, we will outline our strategy to continue development of our lead program, SGT-001, and to explore the potential benefits of SGT-003's novel capsid to deliver our differentiated microdystrophin. This is all supported by a cash position of approximately $180 million at the end of the first quarter of 2022. The board and Solid's leadership team remain committed to the progress of both programs and I'll now summarize our path forward. First, following a thorough assessment of currently available alternatives for the manufacturing of SGT-001, we identified a process that we believe will produce high-quality drug products while narrowing the organization's focus to a single production platform and streamlining our operating structure to a more efficient model. Joel will discuss our revised strategy to advance SGT-001 into late-stage clinical development through transient transfection-based manufacturing. We believe this transition has minimal impact to our timeline for further development through to the potential BLA filing and improves our potential to make a difference for those living with Duchenne. Second, our next generation capsid used in SGT-003 has the potential to offer significant advantages for Duchenne gene therapy as well as for the broader gene therapy field for muscle disorders. We will continue to advance towards IND submission in early 2023 and further de-risk this program and the novel capsid. We expect the clinical proof of concept for SGT-003 in 2023 will provide further support of our next-generation capsid platform. As a result of the focused approach on these programs and Solid's cash runway through Q2 2024, the company will be able to progress through important clinical milestones for both gene therapy programs. I will now hand it over to Joel to go through our SGT-001 update in more detail. Thanks, Ilan. In March, we released an interim analysis of functional and durability data from the first three patients dosed in the high-dose cohort two years after treatment with SGT-001 as part of the IGNITE DMD Phase I/II study. Across all measures, including motor function, pulmonary function, and patient-reported outcome measures, patients are showing consistent, durable improvements after dosing compared to expected declines in untreated patients. We also shared that patients recently dosed in the high-dose cohort demonstrated microdystrophin expression and localization at 90 days within the range of earlier patients in the high-dose cohort at the same period of time. Finally, all IGNITE DMD patients continue to do well with no long-term safety events. These data are important as they continue to support the potential that Solid's nNOS-containing microdystrophin is providing durable benefits to patients and warrants further clinical development. We are now focusing on finalizing late-stage clinical and regulatory strategies supported by a commercial-scale manufacturing process. As part of our platform development efforts, we undertook a comprehensive analysis comparing transient and HSV-based manufacturing processes across a number of factors. We collected multiple data sets from different scales of manufacturing to help us compare the processes and to assess how they would scale for production. Overall, our analysis concluded that by developing SGT-001 and SGT-003 using transient production platforms, we believe we can achieve a high quality and highly potent product, demonstrating high levels of microdystrophin expression in both our in vitro and in vivo expression assays. We can improve our consistency in product supply yields and have access to a broader supply chain, which is reflective of the adoption of this more commonly utilized manufacturing platform. The turnkey commercially scaled solution will allow us to ease our sole reliance on internal development and manufacturing operations. Organizationally, transitioning SGT-001 to a transient-based process will bring Solid under a single manufacturing methodology, allowing us to streamline our operations. Now I will walk through the next 12 months for SGT-001 as we look to resume dosing in the first half of 2023. Importantly, activities to transition to the new manufacturing process have already begun, with product expected to be available in early 2023, aligning well with our regulatory and clinical activities to support dosing patients. The transition to the new manufacturing process was a natural opportunity for us to pause and consider how to proceed with clinical development. As part of our strategy, we have decided to conclude enrollment in IGNITE DMD, and moving forward, patients will be dosed using material from the new process, and we have already begun conversations with the FDA to determine the design of a future clinical study. In addition, we will be initiating a natural history study that will support future clinical activities both for SGT-001 and SGT-003, helping us establish the risk benefit of our programs. There are a number of milestones over the next 12 months that we aim to communicate, such as updates on our discussions with the FDA and additional data coming out of IGNITE DMD, including 1one-year biopsies and functional analyses of all patients dosed in the program, as well as three-year follow-up on functional data from patients four to six. Now I will turn the call over to Carl. Carl? Thanks, Joel, and good morning everyone. I'm pleased to be able to share new data coming out of our novel capsid library development program. Let me briefly review our SGT-003 program. This program utilizes a novel rationally designed capsid that has demonstrated improved muscle tropism compared to AAV9 and packages Solid's differentiated nNOS binding domain-containing microdystrophin. This microdystrophin is the same that is used in SGT-001, and as Joel shared earlier, it has been shown to deliver durable and promising benefits to patients in the IGNITE DMD study. Over the last couple of years, we have shared a variety of data on SGT-003 and it's summarized on this slide. After observing promising data in mouse and human-derived muscle cells, as shown on the left, we compared biodistribution the microdystrophin expression in dystrophic mice of the novel capsid versus AAV9. Improved muscle tropism was observed with the novel capsid that also resulted in an apparent significant reduction in circulating creatine kinase levels versus AAV9, as shown in the center of the slide. Additionally, we ran an in vivo study in wild type mice to determine if we would see similar changes in the level of expression as seen in the MDX mice. For this study, we used reporter CMV luciferase construct. As you can see on the right-hand side of this page, we did observe increased expression in the wild type mice as well. When analyzed, we found more targeted expression to the muscles with lower biodistribution expression in the liver when compared to AAV9. After the promising results seen in human cells and the mouse studies, we wanted to further test the translatability of the increased muscle tropism in non-human primates, as well as have an exploratory look at safety in larger animals. Earlier this year, we initiated a study using CMV luciferase reporter transgene and dosed eight cynomolgus monkeys. Four of them, two male and two female, were dosed with the reporter construct using AAV9, while the other four were dosed with novel capsid being used in SGT-003. Our goal for the novel capsid program has been to see at least a twofold improvement compared to AAV9 in biodistribution to skeletal and cardiac muscle. What we are highlighting here today is an increase in biodistribution greater than the goal of twofold improvement to both skeletal and cardiac tissue. We also see a promising twofold reduction in biodistribution to the liver. On the next slide, we similarly observed an increase in luciferase expression as measured using an activity assay in both skeletal muscle and cardiac muscle, with greater than 10-fold improvement seen in both tissues. Consistent with the biodistribution results, we see decreased expression in the liver with the novel capsid. Overall, these results suggest we may be able to reduce the dose while maintaining expression when compared to AAV9. As we look to next steps for the program, we'll continue R&D efforts on both the novel capsid and SGT-003 program for Duchenne using learning and the promising clinical data from the SGT-001 program. For SGT-003, we are working closely with our manufacturing partner to have product ready to support patient dosing. We are looking to engage with the FDA later this year regarding an IND submission we plan for early 2023. We are very optimistic about the potential that SGT-003 holds for patients. The preclinical data continues to suggest that we may be able to improve expression at a lower dose, therefore reducing viral loads. We will continue to develop this next generation capsid for Duchenne patients with the SGT-003 program, as well as potentially engage with companies developing gene therapies in other muscle-related disorders. With that, I will hand it back to Ilan. Thank you, Carl, and thanks, Joel. We have a lot of work ahead of us, but we have focused our operations to support these two programs, which utilize a single manufacturing approach. That has allowed us to streamline our organization structure and reduce our headcount by approximately 35%, which enables us to extend our runway into Q2 of 2024 and achieve important clinical milestones. Over the next 12 months, we will be sharing further data from long-term patient follow-ups, an update on our regulatory interactions for both SGT-001 and SGT-003, and potential updates on SGT-001 CMC and clinical plans as well as SGT-003 IND filing, clinical trial, and dosing plans. I also want to mention that, as you may have seen in this morning's press release, Joel will be leaving Solid. He has accepted an opportunity to become CEO of an early-stage, privately held gene therapy company. Joel will be staying on through the end of May. Before we open for questions, I wanna take a moment to say thank you. First, I wanna say thank you to all of Solid employees for their tireless efforts to bring our treatments to patients. To those who are unfortunately impacted by the strategic reorganization we announced today, I hope you know that your work has made a meaningful contribution to improving the lives of patients living with Duchenne. For that, I am deeply grateful. I also wanna thank Joel for his eight years of service and commitment to Solid. Joel's been instrumental in building the company, the teams, and the treatments that are being developed at Solid. I now speak on behalf of everyone at Solid when I thank Joel for his leadership, partnership, and friendship and wish him success with his new chapter. Finally, I would like to extend a special thank you to the patients, families, and physicians involved in IGNITE DMD, thanks to whom we are now in a position to move to the next phases of development. Thank you all again for dialing in. We'll take some questions now. Thank you. Again, ladies and gentlemen, to ask the question, simply press star one on your telephone. That is star one. We'll take our first question from Gena Wang of Barclays. Thank you for taking my questions. Joel, congrats on your next journey, and we will certainly miss you. I have two sets of questions. Maybe the first one is regarding the SGT-003. You did show luciferase reporter gene data. Did you test the microdystrophin transgene in the new capsid? Based on the current data, you know, what would be your initial thoughts regarding the phase I dose range? Like, will you be able to go down to the E12 range? My second set of questions is regarding the SGT-001. Now with the new transient transfection-based outsourced manufacturing process, do you need to do additional CMC or comparability study before you move forward to a pivotal study? Great questions, Gena. Thank you. I'll have Carl take on the 003 and Joel respond to the 001. Yeah. Thanks, Gena. It would be great to get down to E12, but I don't think that's possible. You know, we are looking at doing a dose selection study. We still need to do a dose selection study, and so we hope to drop the dose, and you know, so maybe get down by at least twofold. That is what the goal of the program was always to get a twofold difference versus AAV9. It appears that we've done that both in mice and monkeys. The second part of your question was around the luciferase and versus microdystrophin. We didn't dose non-human primates with microdystrophin. We dosed them with the luciferase, but we did do. We did dose mice and compared the luciferase and the microdystrophin. Luciferase has a little bit higher signal, but the microdystrophin in the mice was about threefold while the luciferase in mice is tenfold. We think we're sort of in the right ballpark for the microdystrophin as well. Going into wild type animals that already have dystrophin, it's a bit problematic trying to administer the microdystrophin and evaluate levels. This is good. We did it in wild type mice as well, luciferase, and it showed quite promising results there as well. As a platform, we think this is sort of a really good first step for us. I would just add, you know, Gena, that this, you know, we had a bunch of internal bars that we needed to cross to get excited about 003, and we crossed them, and we are excited, and we're taking them to the clinic. You know, we think there's a lot more potential here outside of Duchenne too. Hopefully, you know, very soon we'll see these patients and see how good it really is. Joe, do you wanna cover 001? Sure. Thanks, Gena, for the question. You know, on comparability, of course, at Solid, we have a lot of experience in demonstrating comparability between different manufacturing methods. In fact, we just recently accomplished that when we transitioned to our second generation-based HSV manufacturing approach. We've already begun to engage with regulators about the path towards dosing our patients with new process, and believe that the comparability will need to be demonstrated, but that can be accomplished through analytical methods and perhaps some, you know, some in vivo dosing to demonstrate comparability overall. Obviously a lot of experience internally with how to demonstrate that comparability and feel confident that we can have a seamless transition between manufacturing methodologies. Maybe I'll just add to this too, that in the process of switching, you know, we did a lot of analytical work, and so we are pretty confident that the new materials will, you know, qualify as at least as good, if not better. Thank you very much. Thank you, Gena. Your next question comes from Joseph Schwartz with SVB Securities. Thanks very much. I'd like to also add my best wishes to Joel in his next endeavors. It sounds like you are satisfied that you understand how to best administer SGT-001 in a safe and effective manner now that you've wrapped up IGNITE. I was wondering if you could summarize what the key features of the risk mitigation protocol are for ensuring that patients who receive SGT-001 can tolerate it optimally. Hey, Joe. Thank you for the question. Obviously, we completed enrollment. We haven't wrapped up the study because we continue to monitor patients, you know, out to five years at least, from dosing, and we've dosed nine and have a number of other patients in the study. I'll have Roxana jump in a little bit on risk benefit and how we feel about moving forward in dosing. Thank you, Ilan. Really good question. Thank you. We feel very confident in the risk-benefit profile of SGT-001 based on the nine dosed subjects to date. Our two-year results show that the patients are experiencing a sustained benefit across all the functional outcomes in terms of motor function, pulmonary and patient-reported outcomes. In terms of the risk mitigation strategy, we feel very confident that this is the right way forward. We are thinking about finalizing that risk mitigation strategy for the new material. Not maybe everything is gonna stay in place as it is right now, but as you know with previous updates, we've shared that we've optimized our eculizumab regimen, and we've definitely optimized our follow-up of the patient previous to infusion and after the infusion in the first couple of weeks through very close monitoring. We're of course assessing that once again to make sure that everything is still applicable for the new material. Okay. Thanks. What are the next steps for SGT-001 then? When do you expect to get back in the clinic, and what types of patients will you be focusing on enrolling in the next study for SGT-001? Have you scheduled an end-of-phase II meeting with the FDA yet? Are you thinking about undertaking a phase III at this juncture? Can you help us understand your strategy there? Sure, Joe. I'll take this. It's a quick one. We've already started engaging with the regulators around the switch. We intend to have material ready to dose patients with SGT-001 early in 2023, and all the aspects of the clinical trial design as well as the number of patients, the age inclusion are being finalized. Okay. We'll stay tuned. Thanks for taking my questions. Thank you. Your next question comes from Maury Raycroft with Jefferies. Hi. Good morning, and thanks for taking my questions. For the new process, besides the scaling and the streamlined process and transient transfection, are there any other fundamental changes we should be aware of? Thanks, Maury. I'll take this one. You know, one key aspect for this solution that we've identified for late-stage development of SGT-001 is that it's already at what we would consider a phase III appropriate and commercial scale. We've done extensive work internally on scaling the HSV process, and as we performed our comprehensive analysis between our internal process and external options, we did seek a process that was already sufficiently optimized for late-stage clinical entry and ultimately commercialization. We're excited to be able to access that. A couple other key aspects of this is that, of course, transient production is a very widely adopted manufacturing platform, and we think that this will enable us to have broader access to a much wider net of supply chain efforts, or supply chain networks. It'll also allow us to, we think overall improve our manufacturability of clinical supply. Really fundamentally it's a streamlining of our manufacturing unified behind a single platform for both gene therapy programs. Got it. That's helpful. Just wondering if you can clarify what you mean by a new outsourced process. I guess, are there gonna be new manufacturing collaborations on the horizon? How much of a contribution does Forge Biologics have in the new process? We're really excited about the work that Forge is doing for us on SGT-003. Simply for diversification purposes as well as the opportunity to work with a commercially scaled process, we are building a new relationship with a new vendor for the production of SGT-001 at those scales. On the aspect of, s orry, actually I'm blanking on the first part of the question. I mean, you basically answered it just. The internal- Anything additional. Yeah. Yeah. Yeah. You know- Yeah. Go ahead. The differentiator there for us is that the HSV process is something that we've worked on extensively internally for the last six or seven years. We are excited to be leveraging external expertise and capabilities to rapidly integrate their expertise into our own around transient production. It's really a notion of, you know, recognizing the incredible work that our internal teams have done to scale and optimize the HSV process, but recognizing that, you know, we can now relieve some of that, those bandwidth constraints by working with external parties, leveraging their proprietary manufacturing platforms, and really focus on bringing our therapy to patients. Got it. That makes sense. Okay, thanks for taking my questions. Thanks, Maury. Thank you. As a reminder, to get in the queue, simply press star one on your telephone. Your next question is from Allison Bratzel with Piper Sandler. Hi. Good morning. Thank you for hosting the call and for taking the questions. First, just a couple clarifications for me on IGNITE DMD, and apologies if you covered these. I just want to make sure I'm clear. I guess how many total patients did end up being dosed in IGNITE DMD? I think we know nine were dosed as of November, so just confirming that that's the total number of patients dosed. Then could you also clarify the cadence for data updates from those patients? I think the prior guidance was to disclose 12-month functional data from patients seven to nine by year-end 2022. Just want to make sure we should still be looking for that. Just lastly for me, a clarification on just on the cash runway. I think the guidance is that you'll have a runway through Q2 2024 through important clinical milestones. Could you just kinda outline the important clinical milestones we should be expecting between now and Q2 2024? Just what does that new cash runway guidance assume for the start of pivotal work? Thanks. Let me try to wrap it all up in a quick answer. With those nine patients we were always gonna dose a couple more, and with this switch, we decided to stop enrollment, evaluate the data, and move to transfection starting early next year. We obviously continue to monitor all the patients that have been dosed. Yes, we will continue to provide additional clinical and biomarker data as it comes in during this year and probably in the future. We are very excited about the durability of the data that we're seeing. You know, we have biopsies out two years that are stable or actually increasing, and we have functional outcomes, especially looking at some of the physical measurements, respiratory measurements. There's some pretty interesting observations there, which we continue to monitor and evaluate and measure and report. The runway will get us, you know, through the next two years and a lot of clinical milestones on both programs. Thank you. Thank you. Our next question comes from Anupam Rama with JP Morgan. Please go ahead. Hey, guys. Thanks so much for taking the question. I have like maybe just a broader strategic question in terms of you're starting dosing for 001 in 2023 and, you know, theoretically your IND goes in for 003 early next year and maybe start dosing patients soon too. Like, why not just prioritize one and maybe extend the cash runway a little bit longer? Good question, Anupam. You wouldn't be surprised it came up internally too. We're not in the business of shooting down things that work. We think 001's got great data that supports continued development. I can tell you as somebody with some first-hand experience of this disease, I would love to see that touch more patients if possible. If 003, once active in patients, does show the same effect that we've seen in mice, that we've seen in monkeys now, certainly the expression levels and the biodistribution levels of the vector, then that's a great finding. It's a really exciting moment for not just Solid, but I think science and muscle diseases. At that point, we can make different decisions than we do today. Right now, we are confident that both these programs deserve a day in the sun. Got it. Thanks for taking my question. Thank you. With that, we conclude our Q&A session and today's call. All parties may now disconnect. Thank you and have a great day.