Solid Biosciences (SLDB) investor relations material

Company focus and pipeline

• Precision genetic medicine company with a primary focus on gene therapy for neuromuscular and cardiac diseases, including Duchenne muscular dystrophy (DMD), Friedreich’s ataxia (FA), catecholaminergic polymorphic ventricular tachycardia (CPVT), and TNNT2 dilated cardiomyopathy.

• Lead program SGT-003 targets DMD, with additional programs in FA, CPVT, and TNNT2 dilated cardiomyopathy at various stages of development.

• Emphasis on next-generation gene therapy technologies, including novel capsids, promoters, and advanced manufacturing processes.

• Actively collaborating with other companies to provide novel gene therapy tools, aiming for 100 collaborations.

SGT-003 for Duchenne muscular dystrophy

• SGT-003 features a unique SLB-101 capsid with RGD peptides for targeted delivery to skeletal and cardiac muscle, and a construct designed to enhance muscle and heart function.

• Clinical data from 15 dosed patients show strong safety and promising efficacy, with no serious adverse events and positive biomarker trends, including improved ejection fraction and reduced troponin.

• Full-to-empty capsid ratios are consistently high, and the lowest dose in gene therapy is used to minimize safety risks, particularly liver-related issues.

• Plans to dose 20 patients by year-end and 30 by end of Q1, with a pivotal meeting with the FDA planned for Q4.

• A global, double-blind, placebo-controlled phase 3 trial is launching, with time to rise as the primary endpoint and 18 months of follow-up.

Friedreich’s ataxia and other pipeline programs

• FA program uses dual-route administration (direct to dentate nucleus and IV) to address both CNS and cardiac manifestations, with initial dosing in adults and plans to expand to younger patients.

• Targeting 15–30% increase in frataxin expression in cardiac tissue, with dosing expected to begin in Q4 at three U.S. sites.

• CPVT program aims to upregulate calsequestrin to prevent arrhythmias, with first-in-human dosing planned for Q4 in adults, followed by younger patients.

• TNNT2 dilated cardiomyopathy program is in GLP toxicology, with potential need for a partner to advance due to resource constraints.