Avidity begins a biomarker cohort in the Phase 1/2 FORTITUDE trial

Avidity Biosciences (RNA) announced the initiation of a biomarker cohort in the Phase 1/2 FORTITUDE trial of delpacibart braxlosiran in people living with facioscapulohumeral muscular dystrophy, or FSHD. Avidity is pursuing a potential accelerated approval path for del-brax and expects enrollment in the biomarker cohort to be completed in the first half of 2025. Avidity also remains on track to initiate a functional cohort in the first half of 2025. In addition, enrollment of the FORTITUDE Open-label Extension study, or OLE, is ongoing. Del-brax is the first investigational therapy designed to treat the underlying cause of FSHD by directly targeting the disease-causing gene, double homeobox 4. Currently, there are no approved therapies for the treatment of FSHD, a rare, hereditary disorder marked by life-long, relentless loss of muscle function, significant pain, fatigue, and progressive disability. The biomarker cohort in the FORTITUDE trial will assess the impact of del-brax 2 mg/kg every six weeks in people living with FSHD, ages 16-70. The primary endpoints of the study are changes in DUX4 regulated gene expression and DUX4 regulated circulating biomarker.