Solid Biosciences' DMD Gene Therapy Shows Promising Early Results

Solid Biosciences has made a significant leap forward in the race to develop an effective gene therapy for Duchenne muscular dystrophy (DMD). The Massachusetts-based biotech company recently reported phase 1 data for its next-generation candidate, SGT-003, that surpassed expectations and sent its stock soaring.

Impressive Phase 1 Data

The phase 1/2 trial of SGT-003 has shown remarkable early results. Day 90 biopsy data from the first three participants revealed that between 70% and 88% of the patients' fibers were positive for dystrophin, with a mean result of 78%. This far exceeds the 40% threshold that Solid's CEO, Bo Cumbo, had previously indicated would be sufficient to "give you enough expression to hit a clinical benefit for these kids."

Mean microdystrophin expression was approximately 110%, consistent across both western blotting and mass spectrometry assessments. However, individual patient results using mass spectrometry ranged from 53% to 152%, indicating some variability in response.

Safety Profile and Expanded Study

The safety data for SGT-003 appears promising, with no serious adverse events or suspected unexpected serious adverse reactions reported in the first six patients who are at least 20 days post-treatment. Notably, there was no evidence of thrombotic microangiopathy, atypical hemolytic uremic syndrome, hemolysis, or hepatic transaminitis—issues that have plagued other gene therapy candidates in the past.

Encouraged by these results, Solid Biosciences is expanding the study. A seventh participant received the gene therapy recently, and the company plans to dose at least 10 patients by early in the second quarter, with aims to double that figure by the fourth quarter. This expansion will support discussions with the FDA about a potential accelerated approval pathway.

Market Response and Financial Moves

The market's response to this news was overwhelmingly positive. Solid Biosciences' stock price surged by almost 90% in premarket trading, reaching over $7.50 per share. This dramatic increase occurred despite the company's simultaneous announcement of a $200 million stock offering priced at just over $4 per share.

As Solid Biosciences continues to advance its DMD gene therapy program, the pharmaceutical industry will be watching closely to see if these early promising results can be replicated in a larger patient population and potentially lead to a groundbreaking treatment for this devastating genetic disorder.