Solid Biosciences announced on Mar. 13 that its investigational gene therapy, SGT-003, increased the expression of key markers in patients with Duchenne muscular dystrophy, based on results from a Phase 1/2 clinical trial. The company said these findings support the biological mechanism of the therapy and may help advance discussions with the Food and Drug Administration.
The announcement is significant because Duchenne muscular dystrophy is a severe genetic disorder characterized by progressive muscle weakness and cardiac complications due to deficient or dysfunctional dystrophin protein. Current treatment options are limited, making advances in gene therapy important for affected patients.
Analysts at Jefferies said, "The data point to a differentiated product profile that we expect will pave the way for a productive discussions w/ the FDA." William Blair analysts also commented on the results, stating that SGT-003 "remains the only late‑stage program to show early cardiac benefit across biomarkers and function, which we continue to view as a meaningful differentiator in a disease where cardiac involvement is a major driver of long‑term morbidity." They added that this latest readout "strengthens the biologic plausibility of SGT‑003’s treatment effect."
In the INSPIRE DUCHENNE Phase 1/2 trial, interim data showed that biopsies from 20 treated patients after 90 days demonstrated robust expression levels of microdystrophin and restored fibers positive for molecular indicators associated with muscle integrity. Solid Biosciences explained these fibers are part of the dystrophin-associated protein complex, which is typically absent in patients with Duchenne muscular dystrophy. The study did not include an untreated control group; instead, efficacy was measured against each patient's baseline levels.
Preliminary cardiac assessments indicated stabilized or improved systolic function among treated patients, especially those who had weaker heart function at baseline. Improvements were also observed in other biomarkers related to muscle health.
Solid Biosciences has reached an agreement with the FDA to conduct a Phase 3 placebo-controlled study for SGT-003. The company reported that participant screening continues and expects to administer the first dose this quarter while ongoing meetings with regulators address potential accelerated approval.
