Solid Biosciences (SLDB) investor relations material

Strategic focus and pipeline overview

• Emphasis placed on gene therapies for Duchenne muscular dystrophy (DMD) and Friedreich's ataxia (FA), with other cardiac programs progressing more slowly due to resource prioritization.

• Proprietary platform develops novel delivery tools, including capsids and dual plasmids, shared with academic labs to advance next-generation gene therapies.

• High demand observed for DMD therapy, with the INSPIRE trial quickly filled and over 100 patients seeking enrollment.

• Current focus is on ambulatory and pre-ambulatory DMD patients, with plans to expand to non-ambulatory populations in the future.

• Approximately 50% of eligible DMD patients (2,000–3,000) remain candidates for the therapy after accounting for antibodies and exclusion criteria.

Clinical trial progress and regulatory plans

• INSPIRE trial for DMD has dosed 53 patients, with a few more to be treated using commercial material for bridging data to phase III.

• Phase III trial design for DMD was discussed and approved with the FDA, with ongoing data analysis and external control matching.

• Key functional endpoints include Stride Velocity 95th Centile, Time to Rise, four-stair climb, and 10-meter walk/run, with cardiac data used for safety.

• Regulatory and clinical data updates, including potential accelerated approval discussions, are expected late this year or early next year.

• FA program aims to dose seven patients by year-end, targeting a registrational trial in the second half of next year.

Scientific and technical highlights

• DMD therapy leverages a microdystrophin construct optimized for flexibility and protein recruitment, based on Dr. Chamberlain's research.

• Novel capsid (POLARIS-101) designed for enhanced muscle and heart biodistribution, rapid clearance, and improved safety profile.

• Preclinical models showed 3–10x greater biodistribution in muscle and up to 20x in heart compared to AAV9.

• Comprehensive biomarker approach tracks multiple biological correlates to predict clinical benefit, rather than relying on a single marker.

• FA program uses a dual administration route to address both neurological and cardiac symptoms, with streamlined outpatient surgery.