Solid Biosciences Inc. Q1 FY2022 earnings call

• Ilan highlighted Solid's focus on Duchenne therapies with two potential treatments, SGT-001 and SGT-003, and a cash position of approximately $180 million at the end of Q1 2022.
• Joel discussed transitioning the manufacturing approach for SGT-001 to a transient transfection-based process, believing it will produce high-quality drug products, streamline operations, and resume dosing in H1 2023.
• Carl shared new preclinical data on SGT-003's novel capsid, which demonstrated improved muscle tropism, reduced creatine kinase levels in mice, and promising results in nonhuman primates.
• Organizational strategy is aligned behind the two programs, with Joel leaving the company by the end of May, and acknowledgment of employees' efforts and thanks to patients, families, and physicians involved in IGNITE DMD.

The company focuses on two Duchenne therapies, SGT-001 and SGT-003. No specific revenue contribution percentages are provided for product segments as the focus is on development of these therapeutic programs.

• SGT-001 will transition to transient transfection-based manufacturing, with plans to resume dosing in H1 2023, conclude IGNITE DMD enrollment, and engage with the FDA on future study design.
• SGT-003 is moving towards an IND submission in early 2023, aiming for clinical proof of concept in 2023.
• The company has a cash runway through Q2 2024 to support important clinical milestones for both gene therapy programs.

• Uncertainty inherent in the clinical development and regulatory process.
• Impact of the COVID-19 pandemic and other risks described in the Risk Factors section of the most recently filed annual report on Form 10-K and other periodic reports filed with the SEC.

Q: Regarding SGT-003, did you test the microdystrophin transgene in the new capsid and initial thoughts on Phase I dose range?

A: Carl discussed testing luciferase reporter gene and microdystrophin transgene, noting potential dose reduction and positive results in preclinical studies.

Q: Regarding SGT-001, do you need additional CMC or comparability study before moving to pivotal study?

A: Joel discussed experience in demonstrating comparability between manufacturing methods and engaging with regulators on the path to dosing patients with the new process.

Q: Summarize risk mitigation protocol for SGT-001 ensuring optimal patient tolerance?

A: Roxana discussed the risk-benefit profile based on patient monitoring, optimizing eculizumab regimen, and close post-infusion monitoring.

Q: Next steps for SGT-001 and when to expect clinic return?

A: Ilan mentioned engaging with regulators, material ready for patients early 2023, and finalizing clinical trial design.

Q: Fundamental changes in new manufacturing process besides scaling?

A: Joel discussed streamlined manufacturing, broader supply chain access, and leveraging external expertise for transient production.

Q: Total patients dosed in IGNITE DMD and data update cadence?

A: Ilan mentioned 9 patients dosed with plans to monitor and provide ongoing clinical and biomarker data.

Q: Cash runway and important clinical milestones between now and Q2 '24?

A: Ilan discussed runway through Q2 2024 supporting clinical milestones on both programs.

Q: Why not prioritize one program to extend cash runway?

A: Ilan stated both programs have promising data and deserve development, with potential for broader impact outside Duchenne.