Avidity Biosciences (RNA) Morgan Stanley 23rd Annual Global Healthcare Conference summary

Pipeline progress and upcoming catalysts

• Three late-stage clinical trials are ongoing, with three BLA filings planned within 12 months starting this year.

• First BLA for Del-zota in DMD44 to be filed by year-end, with launch expected in 2026.

• Two additional BLAs for Del-zota (myotonic dystrophy) and Del-brax (FSHD) are planned for the second half of 2026.

• Key data readouts include Del-zota functional data this month, MARINA-OLE data in Q4, and HARBOR 30-week efficacy data in H1 2026.

• Fortitude biomarker cohort for FSHD will have a full data readout in Q2 2026.

Clinical program insights and learnings

• AOC platform uses a consistent antibody and linker, with therapeutic payloads tailored per indication.

• Over 250 patient-years of safety data and 30 patients dosed weekly across programs.

• Dosing intervals were optimized based on clinical experience, now ranging from every 6 to 8 weeks depending on the program.

• siRNAs chosen for DM1 due to potency, durability, and ability to target muscle tissue effectively.

• Dosing frequency was increased from quarterly to every 8 weeks based on patient feedback and biomarker data.

HARBOR trial and DM1 strategy

• HARBOR is the first global phase III study in myotonic dystrophy, with VHAT as the primary endpoint.

• Secondary endpoints include Hand Grip, QMT, and DM1 Active, all considered well-powered and likely to show statistical significance.

• Regulatory alignment achieved across the U.S., Europe, and Japan for trial design and endpoints.

• Cardiac endpoints are not tracked in HARBOR but may be studied post-marketing.