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

Dear Duchenne Community,

This morning we issued a press release providing an update on Solid’s business. The update included an overview of long-term expression and functional data presented during the third quarter and the announcement of an important public-private collaboration we launched in partnership with REGENXBIO with the support of the FDA. We are excited to share the progress we have made since our last update to further our mission of advancing meaningful treatments for patients.

Updates in IGNITE DMD Phase I/II Clinical Trial

In September, Solid presented long-term expression and functional data in the ongoing IGNITE DMD Phase I/II clinical trial at the World Muscle Society 2021 Virtual Congress for the first three patients in the high dose (2E14 vg/kg) cohort. Analysis of biopsy data from patients 4-6 taken at 2 years (Patient 4), 1.5 years (Patient 5) and 1 year (Patient 6) post dosing indicate evidence of durable and widespread expression of microdystrophin protein. In addition, patients dosed with SGT-001 exhibited sustained benefit across all functional and patient-reported outcomes measures over a period when natural history would suggest a decline.

Also in September, Solid reported additional positive pulmonary function data from the first six patients in the IGNITE DMD Phase I/II clinical trial. The data, which was presented at the Child Neurology Society 50th Annual Meeting, showed sustained benefit in two additional assessments of pulmonary function in treated patients one-year post dosing when natural history would suggest a decline. We are encouraged by the data from pulmonary function endpoints seen in IGNITE DMD, especially given that loss of pulmonary function impacts all patients living with Duchenne.

The recent interim data analysis enhances our understanding of the role that SGT-001 may play in improving outcomes for patients with Duchenne. As we look advance the IGNITE DMD clinical trial, we will continue to follow dosed patients and collect data to support the potential benefit of SGT-001 and expect to begin dosing additional patients in our IGNITE DMD Phase I/II clinical trial before the end of the year.

Pipeline Update

Solid’s next generation adeno-associated virus (AAV) capsid pipeline program, SGT-003, continues to advance and demonstrate enhanced muscle tropism and microdystrophin expression in preclinical studies. In addition, we recently announced a partnership with Forge Biologics, a cell and gene therapy-focused contract development and manufacturing organization (CDMO), to advance the development and manufacturing of SGT-003. We are looking toward a target Investigational New Drug (IND) filing in early-2023.

Recent Company Developments

Solid, in collaboration with REGENXBIO, formally launched the Pathway Development Consortium (PDC), a multistakeholder initiative that aims to identify, develop, expand and maintain pathways to effective therapies for patients diagnosed early in life with rare diseases. The PDC seeks to achieve these goals by bringing together a broad and diverse group of stakeholders from the rare disease and AAV gene therapy communities, including patients, industry, regulators, academia and payers, among others, for meaningful scientific and policy discussions.

Upcoming Community Presentations

  • Action Duchenne Annual Conference: November 2021
  • Parent Project Italy: February 2022

We are encouraged by the long-term expression and functional outcomes, as well as pulmonary function data collected to date and are excited by the promise of Solid’s expanding pipeline. The team at Solid Biosciences continues its steadfast commitment to the Duchenne community, which propels our work as we drive toward our mission and urgently advance therapies for patients who are waiting.



Your Solid Biosciences Team