Dyne Therapeutics, Inc. has announced significant developments in its pursuit of accelerated approval for dyne-101, its investigational therapeutic for the treatment of myotonic dystrophy type 1 (DM1). The company revealed that the U.S. Food and Drug Administration (FDA) has granted breakthrough therapy designation for dyne-101 in DM1, and an updated plan for obtaining accelerated approval in the U.S. following a type C meeting with the FDA and analysis of new long-term functional data.
Dyne submitted a revised protocol for the ongoing registrational expansion cohort of the Achieve trial with video hand opening time (vhot) as the primary endpoint for potential accelerated approval. The company plans to enroll 60 participants, randomized 3:1 to receive dyne-101 6.8 mg/kg q8w or placebo, and is adding additional clinical trial sites, including those in the U.S., to support enrollment.
The company expects to complete enrollment in the registrational expansion cohort in Q4 2025, with data from this cohort planned for mid-2026 to support a potential U.S. accelerated approval submission in late 2026. Dyne also intends to initiate a confirmatory phase 3 clinical trial in Q1 2026 and is pursuing expedited approval pathways globally for dyne-101.
New long-term data from the multiple ascending dose (MAD) portion of the Achieve trial showed that dyne-101 demonstrated robust and sustained improvement in myotonia as measured by vhot, as well as sustained improvements across multiple other endpoints. Notably, mean improvements at 6 months were sustained at 12 months for vhot, 10mwr, 5xsts, myotonic dystrophy health index (MDHI), and quantitative muscle testing (QMT).
The company reported updated safety and tolerability data from 56 patients enrolled through the 6.8 mg/kg q8w cohort of the Achieve trial, indicating a favorable safety profile with no related serious treatment emergent adverse events identified.
In terms of financials, Dyne expects that its cash, cash equivalents, and marketable securities as of March 31, 2025, will be sufficient to fund its operations into the fourth quarter of 2026, with $677.5 million in cash, cash equivalents, and marketable securities as of that date.
Dyne Therapeutics will host an investor and analyst conference call on June 17, 2025, at 8:00 a.m. ET to discuss these updates. The company has also provided an accompanying slide presentation for the event and an updated corporate presentation. Following these announcements, the company's shares moved -4.09%, and are now trading at a price of $13.82. If you want to know more, read the company's complete 8-K report here.
