Insights:Letter to the Duchenne Community: Data and IGNITE DMD Phase I/II Clinical Trial Update

Dear Duchenne Community,

This morning we issued a press release providing an update on Solid’s business as well as data from our ongoing Phase I/II IGNITE DMD clinical trial of our lead gene therapy candidate, SGT-001. This included positive two-year safety and efficacy results from the first three patients treated in the high dose (2E14 vg/kg) cohort as well as muscle biopsy results from the three most recently dosed patients that were consistent with previously dosed patients in the high dose cohort. We are excited to share details about our recent progress to further our mission of advancing meaningful treatments for patients with Duchenne.

IGNITE DMD Phase I/II Clinical Trial Update

Today, we reported two-year interim efficacy and safety data from the first three patients treated with SGT-001 in the high dose (2E14 vg/kg) cohort as part of IGNITE DMD. Data suggest improved motor function as well as improvements in pulmonary function and patient-reported outcome measures at the two-year time point, compared to the declines that would be expected in each of these assessments from Duchenne natural history studies. These results are consistent with those reported by Solid at the 12-month and 18-month time points for the same IGNITE DMD patients. In addition, no new treatment-associated safety findings in the long-term follow-up for these patients were observed.

We also announced an update of day 90 skeletal muscle biopsy data, which includes analysis of needle biopsies collected from the three most recently dosed patients in the high dose cohort. The results show that microdystrophin expression levels for these newest patients fall within the same range as levels observed for the first three patients dosed in the high dose cohort.

Solid’s Head of Clinical Development, Roxana Donisa Dreghici, will present this data in an oral session on Wednesday, March 16 at the 2022 Muscular Dystrophy Association (MDA) Clinical and Scientific Conference, taking place March 13-16 in Nashville, Tenn.

These data enhance our understanding of the role that SGT-001 may play in improving outcomes for patients with Duchenne. We continue to advance the IGNITE DMD clinical trial and will continue to follow dosed patients and collect data to support the potential benefit of SGT-001 and expect to dose additional patients this year.

Upcoming Community Presentations

  • CureDuchenne FUTURES National Conference: May 27-29, 2022
  • Parent Project Muscular Dystrophy Annual Conference: June 23-26, 2022

We are encouraged by the long-term motor function, pulmonary function, and patient reported outcome measures data collected to date and are excited by the promise of SGT-001 as well as our expanding pipeline. The team at Solid Biosciences remains fully committed to the Duchenne community and to our purpose of improving the lives of patients living with Duchenne.

#TogetherWeAreSolid

Sincerely,

Your Solid Biosciences Team