Dyne Therapeutics (DYN) Stifel 2024 Healthcare Conference summary

DM1 program updates

• IND clearance for DM1 in the US was achieved ahead of schedule, enabling accelerated clinical progress.

• Six-month data at 6.8 mg/kg and 12-month data at 5.4 mg/kg will be disclosed in early January, including splicing, functional, and patient-reported outcomes.

• Dose selection for the registrational cohort will be based on these data, aiming for an accelerated approval pathway using splicing as a surrogate endpoint corroborated by functional and PRO data.

• Clinical endpoints of interest include muscle strength, QMT, ankle dorsiflexion, hand grip, and CNS-related PROs such as fatigue and brain fog.

• Manufacturing and commercial planning are underway, with a commercial leader hired and scale-up activities ongoing.

DMD program progress

• Strong functional and dystrophin data at 10 and 20 mg/kg doses, with broad and uniform dystrophin distribution observed in muscle tissue.

• The registrational cohort includes 32 new patients plus 50 from earlier cohorts, all moving to 20 mg/kg, totaling over 80 patients.

• Functional improvement at six months exceeded minimal clinical endpoints, supporting rapid advancement.

• The program is advancing without additional FDA engagement, based on confidence in the platform and data.

• Safety concerns seen in other programs (e.g., Sarepta PPMO) are not seen as affecting this program's regulatory path.

Pipeline and platform expansion

• FSHD program is in IND-enabling studies, using siRNA to target DUX4, with strong preclinical knockdown data.

• Early work on DMD exon skipping for exons 53, 45, and 44 is ongoing, with plans for an umbrella development approach.

• The platform demonstrates versatility, supporting ASO, PMO, and siRNA modalities, and is being explored for additional indications such as Pompe.

• The company is focused on efficient infrastructure build-out for rare disease launches, leveraging full asset ownership.

• End-of-year data readouts are expected to be pivotal for both clinical and commercial strategy.