- Avidity Biosciences (RNA, Financial) reports positive Phase 1/2 FORTITUDE trial data for FSHD treatment.
- Delpacibart braxlosiran (del-brax) shows significant functional and biomarker improvements.
- Accelerated BLA submission planned for H2 2026; Phase 3 FORWARD study initiated.
Avidity Biosciences (RNA) has announced promising topline results from the Phase 1/2 FORTITUDE trial, assessing delpacibart braxlosiran (del-brax) for the treatment of Facioscapulohumeral Muscular Dystrophy (FSHD). The trial highlighted del-brax's potential as the first therapy aimed at the DUX4 gene, which is responsible for causing FSHD. Compared to the placebo, del-brax demonstrated consistent enhancements in functional mobility, muscle strength, and quality of life across multiple measures.
The clinical trial involved 39 participants divided into two dosing groups: 2mg/kg and 4mg/kg. Over a 12-month period, del-brax was administered every six weeks for the initial three months, followed by dosing every 13 weeks. Significant improvements were observed in the 10-Meter Walk-Run test, Timed Up and Go, and quantitative muscle testing scores, along with decreased levels of KHDC1L and creatine kinase biomarkers. No severe adverse events were reported, indicating a favorable safety profile.
Recognizing the potential of del-brax, Avidity Biosciences is gearing up to submit a Biologics License Application (BLA) for accelerated approval in the second half of 2026. Furthermore, the company has launched the Phase 3 FORWARD study as a continuation of their efforts to address the unmet needs of approximately 45,000 to 87,000 FSHD patients in the United States and Europe, where no approved treatments currently exist.
