Solid Biosciences Inc at Jefferies Gene Therapy/Editing Summit (Virtual) Transcript

The following is excerpted from the question-and-answer section of the transcript.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Great. Yes, I think that was a great overview. And you talked a little bit about what makes 001 unique. Maybe if you can talk more about 001 and some of the data that you've reported so far.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Great. Maybe if you could talk about the first gen versus the second gen manufacturing. And there's an imminent catalyst coming out that we're looking forward to which is going to be the year end, a 90-day biopsy data in microdystrophin expression from patient seven and eight from the IGNITE study. So maybe if you can talk about that and what your expectations are for the year-end update.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And can you say if you already have the biopsies from patient seven and eight?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Okay. And for safety, I guess, what are the expectations and what should we be looking for there?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. That's helpful. And maybe going back to data you've already reported. Can you talk about expectations for 001 durability in respect to expression and functional benefit? For patients 4 through 6 for the first gen vector, you reported some data very recently at the World Muscle Society and then also at the CNS meeting. Maybe if you can just talk about your thoughts on durability and how that informs development strategy.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And for the data from World Muscle and CNS, can you help contextualize the data there in respect to natural history in DMD? And maybe provide some perspective into how functional measurements are performed and how frequently in these studies?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And for younger patients, would you predict a more, I guess, a greater magnitude of benefit, or how do you think about that?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And for patient nine, is there anything additional you can say about that patient at this point as far as the age or baseline characteristics go?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Makes sense, and I think that's a good segue into just if you can comment on your latest patient screening and enrollment and whether you are seeing success there with that.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And on clinicaltrials.gov, you've got an equal 16 listeners, so 16 patients potentially for this study. Do you need 16 patients in order to complete this study before moving to the next step, or what's the goal?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And you mentioned the risk mitigation plan. Maybe if you can talk a little bit more about that. And so that involved implementing the weight requirements and the 45-day lag time between dosing patients. Maybe comment on how that's working for you in the near-term. Do you think this protocol will remain part of your registrational study in the long term?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. Okay. And just wanted to check to see if you've had any recent discussions with regulators that you can comment on. I guess that's the question.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And can you tell us about any strategies for potentially accelerating enrollment and dosing in the next few months? REFINITIV STREETEVENTS | www.refinitiv.com | Contact Us consent of Refinitiv. 'Refinitiv' and the Refinitiv logo are registered trademarks of Refinitiv and its affiliated companies. OCTOBER 28, 2021 / 6:00PM, SLDB.OQ - Solid Biosciences Inc at Jefferies Gene Therapy/Editing Summit (Virtual)

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. Okay. And we talked a little bit about comparing to natural history earlier. What's your goal for efficacy for showing improvement over natural history?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Okay. And what kind of data package would make you move forward with a pivotal study and consider an accelerated path for approval?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. Okay. And in this space, safety has been a topic. And more recently, some evidence showed that severe adverse events were associated with specific genotypes and this led to Pfizer's recent decision to exclude specific DMD genotypes from its ongoing Phase 3. And previously, Sarepta also excluded specific mutations in this study due to AEs. So in line with these, have you observed any genotype specific adverse events among your patients? And what are your plans for monitoring?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And are you able to comment -- so even though you are not disclosing the genotypes, are able to comment on the distribution and nature of DMD genotypes among enrolled patients in your study? REFINITIV STREETEVENTS | www.refinitiv.com | Contact Us consent of Refinitiv. 'Refinitiv' and the Refinitiv logo are registered trademarks of Refinitiv and its affiliated companies. OCTOBER 28, 2021 / 6:00PM, SLDB.OQ - Solid Biosciences Inc at Jefferies Gene Therapy/Editing Summit (Virtual)

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And this space is becoming increasingly crowded, which is good for patients, but wondering how you guys are thinking about positioning competitively in this space, especially against Sarepta and Pfizer.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And also wanted to see what your takeaways were based on commentary and guidance from FDA's recent cell and gene therapy [focused outcome].

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And recently you just spoke with Forge, which is a newer company in the space. I think a partnership with you guys was announced. And just wondering how you think this relationship with Forge can help enhance 003's manufacturing abilities and the product that's used. REFINITIV STREETEVENTS | www.refinitiv.com | Contact Us consent of Refinitiv. 'Refinitiv' and the Refinitiv logo are registered trademarks of Refinitiv and its affiliated companies. OCTOBER 28, 2021 / 6:00PM, SLDB.OQ - Solid Biosciences Inc at Jefferies Gene Therapy/Editing Summit (Virtual)

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it. And do you have plans for expanding into other therapeutic areas besides DMD?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And wanted to check too to see how the partnership with Ultragenyx is going, and would you consider similar type partnerships?

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Got it, okay. And it's great speaking with you guys. Maybe if you can just quickly go through key catalysts ahead that investors should be focused on for the upcoming six months.

Question: Maury Raycroft - Jefferies Group LLC - Analyst : Great, okay. Well, thanks for joining us. And I look forward to seeing the progress. REFINITIV STREETEVENTS | www.refinitiv.com | Contact Us consent of Refinitiv. 'Refinitiv' and the Refinitiv logo are registered trademarks of Refinitiv and its affiliated companies. OCTOBER 28, 2021 / 6:00PM, SLDB.OQ - Solid Biosciences Inc at Jefferies Gene Therapy/Editing Summit (Virtual)