Solid Biosciences (SLDB) 25th Annual Needham Virtual Healthcare Conference summary

Pipeline and program highlights

• Focused on Duchenne muscular dystrophy (DMD) and Friedreich's ataxia (FA), with multiple cardiac programs in development, including a major Mayo Clinic collaboration for a large cardiac indication.

• DMD program features a unique microdystrophin transgene with nNOS and cavin-4 domains, aiming for accelerated FDA approval due to high unmet need and novel protein design.

• POLARIS-101 capsid enables rapid, high transduction in skeletal and cardiac muscle, with liver de-targeting properties and a strong safety profile across 44 dosed patients.

• Comprehensive biomarker panel shows consistent, robust muscle integrity improvements and slowed degeneration, with functional video evidence submitted to the FDA.

• FA program uses dual-route administration to target the dentate nucleus and heart, achieving high protein expression and early signs of functional improvement in severe patients.

Clinical data and safety

• DMD data show high, consistent microdystrophin expression, improved membrane stability, reduced tissue injury, and preservation of muscle fibers, with a 44% reduction in embryonic myosin heavy chain.

• Cardiac function remains stable or improves in both normal and low-normal patients, with blinded echo rereads planned to confirm findings.

• No drug-induced liver injury, myocarditis, aHUS, or TMA observed; ALT and AST decline rapidly post-dose, attributed to liver de-targeting.

• Steroid regimen is tapered quickly, with all patients at baseline by day 60, ensuring functional data reflect drug effect rather than steroid influence.

• No cytopenias or rhabdomyolysis reported after excluding high-risk mutations; safety profile considered a key differentiator for market adoption.

Manufacturing, delivery, and future plans

• Consistent expression attributed to rational capsid design, muscle-specific promoter, and high manufacturing purity (75% full-to-empty ratio).

• Incremental improvements in delivery, manufacturing, and protein design drive next-generation gene therapy performance.

• Plans to license new capsids to other companies and develop 3rd-generation DMD programs to expand market share.

• FA program aims to dose five patients by year-end, with a data readout expected around the JPMorgan conference timeframe.

• Company has transitioned from preclinical to clinical stage in three years, with ambitions to transform DMD and FA treatment landscapes.