Novartis Del-Brax FORTITUDE Phase 1/2 Biomarker Cohort Meets Primary Endpoint in Facioscapulohumeral Muscular Dystrophy
Novartis (which acquired Avidity Biosciences in February 2026) announced June 11 that the biomarker cohort of the Phase 1/2 FORTITUDE trial of delpacibart braxlosiran (del-brax, AOC 1020) met its primary and key secondary endpoints, with reductions in KHDC1L (cDUX target) and creatine kinase indicating strong target engagement and reduced muscle damage in adults with FSHD. The data validate the dosing regimen now being used in the Phase 3 FORWARD trial enrolling 200 patients across the US and Europe. Del-brax is an antibody-oligonucleotide conjugate aimed at aberrant DUX4 expression, the same conjugate-modality family as the peptide-oligonucleotide conjugates from PepGen (PGN-EDODM1 for DM1) and Vertex (VX-670).