Dyne Therapeutics’ DYNE-101 shows efficacy in two Phase 1/2 trials

Dyne Therapeutics announced positive clinical data from its ongoing Phase 1/2 ACHIEVE trial of DYNE-101 in patients with myotonic dystrophy type 1 – DM1 – and its ongoing Phase 1/2 DELIVER trial of DYNE-251 in patients with Duchenne muscular dystrophy or DMD who are amenable to exon 51 skipping. New data from both trials demonstrated impact on key disease biomarkers as well as improvement in multiple functional endpoints and favorable safety profiles. In the ACHIEVE trial, DYNE-101 demonstrated robust muscle delivery and dose-dependent, consistent splicing correction while also showing improvement in multiple functional endpoints and patient reported outcomes. Dyne also reported safety and tolerability data from 56 patients enrolled through the 6.8 mg/kg Q8W cohort of the MAD portion of the ACHIEVE trial. DYNE-101 demonstrated a favorable safety profile. The majority of treatment emergent adverse events were mild or moderate and no related serious treatment emergent adverse events have been identified. In the Phase 1/2 DELIVER trial of DYNE-251 in DMD, 10 mg/kg of DYNE-251 Q4W demonstrated dose-dependent exon skipping and dystrophin expression. Dyne plans to continue to engage with global regulators this year on ACHIEVE and DELIVER, and anticipates providing an update on the path to registration for both DYNE-101 and DYNE-251 by the end of 2024. Both trials are designed to be registrational, and the company is pursuing expedited approval pathways for both programs. In DM1, Dyne continues to pursue an accelerated approval pathway for DYNE-101, including leveraging splicing as a potential surrogate biomarker. In DMD, Dyne has confirmed that the FDA precedent for using dystrophin as a surrogate biomarker for accelerated approval remains available. Dyne expects to provide updates on programs, including facioscapulohumeral muscular dystrophy and other pipeline opportunities during 2024.