Avidity Biosciences Completes Enrollment in Biomarker Cohort in Phase 1/2 FORTITUDE™ Trial

Letter from Avidity Biosciences to the FSHD community:

March 31st, 2025

Dear FSHD Community,

Today, we are very pleased to share with you that we have completed enrollment in the biomarker cohort in the Phase 1/2 FORTITUDE clinical trial of delpacibart braxlosiran (del-brax/) in people living with facioscapulohumeral muscular dystrophy (FSHD). You can view our full press release of today’s FSHD news here

Avidity Biosciences Completes Enrollment in Biomarker Cohort in Phase 1/2 FORTITUDE™ Trial for Delpacibart Braxlosiran (del-brax) in People Living with Facioscapulohumeral Muscular Dystrophy

The biomarker cohort in the FORTITUDE trial is designed to assess the impact of del-brax 2 mg/kg administered every six weeks versus placebo for 12 months in people living with FSHD, ages 16-70. Avidity anticipates initiation of a Global Phase 3 trial in the second quarter of 2025.

We are advancing our clinical studies for del-brax and understand the urgency to bring a potential new treatment to people living with FSHD.

We want to thank the entire patient community for your time, commitment and continued contributions in assisting Avidity with the development of del-brax. We are so grateful to the current and future participants, their families, the investigators and their teams as we work together to advance del-brax in clinical development.

We encourage you to contact your doctor if you have any questions about del-brax, and FORTITUDE.

Sincerely,
The Avidity Team