Solid Biosciences Inc. has announced positive initial data from the company’s Phase 1/2 INSPIRE DUCHENNE trial evaluating SGT-003. SGT-003 is a gene therapy candidate for the treatment of Duchenne that delivers a microdystrophin via their novel AAV capsid designed to increase skeletal and cardiac muscle targeting while detargeting the liver.

Solid shared interim 90-day biopsy data reported in the first three participants (two boys at age 5 and one at age 7) across three different dystrophin expression methodologies. For the three patients with biopsies, they showed an average microdystrophin expression of 110% normal as measured by western blot, 108% average microdystrophin expression by mass spectrometry, and average percent positive dystrophin fibers by immunofluorescence of 78%. 

Additionally, the results indicate improvements in multiple muscle health biomarkers, as well as significant reductions in all evaluated biomarkers of muscle damage associated with Duchenne. This, Solid notes, may provide preliminary evidence of a beneficial effect in muscle integrity, including potential early signals of a positive cardiac benefit of SGT-003. SGT-003 was also well-tolerated in the first six participants dosed and has a favorable safety profile, with no serious adverse events observed.

Solid has indicated that participant enrollment continues, and the company expects to dose approximately 20 total participants by Q4 2025. Solid plans to request a meeting with the FDA in mid-2025 to discuss the potential for an accelerated approval regulatory pathway for SGT-003.

Read Solid’s community letter here and the company’s press release here.

Upcoming Webinar: Solid Biosciences Update on Gene Therapy Candidate SGT-003

Please join PPMD and members of the Solid Biosciences team for a community webinar on Tuesday, February 25, 2025 at 1:00PM ET to review initial positive data from the INSPIRE DUCHENNE study of SGT-003, a next-generation microdystrophin gene therapy candidate. The Solid team will provide a current update on the study, including new microdystrophin expression and biomarker results from participants who have reached the Day 90 timepoint, as well as a safety update from the first six participants dosed. In addition, they will outline plans for continued dosing in the expanded study. Register for the webinar here and submit any questions you may have in advance here.