Delpacibart braxlosiran (del-brax) - (FORTITUDE)

Aug. 7, 2025: Avidity Biosciences, Inc. (NASDAQ: RNA) reported Q2 2025 financial results and provided program/regulatory updates across three neuromuscular candidates, targeting up to three BLA submissions within ~12 months and potential first U.S. commercial launch in 2026.

• Delpacibart zotadirsen (del-zota) in DMD amenable to exon 44 skipping (DMD44): FDA granted Breakthrough Therapy designation (July 2025). Company remains on track for a BLA submission at year-end 2025 (its first BLA). Plans to present topline and functional data from the ongoing EXPLORE44-OLE trial in Q4 2025.

• Delpacibart etedesiran (del-desiran) in myotonic dystrophy type 1 (DM1): Completed enrollment in the Phase 3 HARBOR trial (July 2025). Updates from MARINA-OLE (including long-term 4 mg/kg efficacy/safety) expected in Q4 2025; publication of analyses from Phase 1/2 MARINA expected in 2025. HARBOR topline data anticipated in Q2 2026; marketing application submissions in the U.S./EU/Japan anticipated to start in 2H 2026.

• Delpacibart braxlosiran (del-brax) in FSHD: In June 2025, aligned with FDA on accelerated and full approval pathways; reported positive topline Phase 1/2 FORTITUDE dose-escalation data (functional/QoL improvements vs placebo; reductions in KHDC1L/cDUX and creatine kinase; favorable long-term safety/tolerability) and initiated confirmatory global Phase 3 FORTITUDE-3. FORTITUDE biomarker-cohort topline expected Q2 2026; planned accelerated-approval BLA submission in 2H 2026.

Financials: Cash/cash equivalents/marketable securities ~$1.2B as of June 30, 2025; additional $185.5M net ATM proceeds post-quarter; runway to mid-2027.