Dyne Therapeutics wins FDA priority review for DMD drug, PDUFA Jan 2027

Dyne Therapeutics said the Food and Drug Administration accepted its Biologics License Application for z-rostudirsen in Duchenne muscular dystrophy amenable to exon 51 skipping, granting Priority Review with a Jan. 21, 2027, PDUFA date.

"The FDA's acceptance of our BLA for z-rostudirsen marks an important milestone for individuals living with DMD amenable to exon 51 skipping and a defining step in Dyne's evolution toward becoming a commercial-stage company," John Cox, president and chief executive officer of Dyne, said.

The company reported a second-quarter net loss of $178.6 million, or $1.08 a share, compared with a net loss of $110.9 million, or 97 cents a share, a year earlier. Research and development expenses rose to $152.2 million from $99.2 million, driven by increased manufacturing and clinical costs for z-rostudirsen and z-basivarsen. General and administrative expenses climbed to $29.5 million from $16.6 million as the company invested in pre-commercial capabilities.

Dyne held $898.5 million in cash, cash equivalents and marketable securities as of June 30. In July, the company completed an underwritten public offering of 21 million shares at $20.50 each, raising estimated net proceeds of about $405 million. Combined, the company expects cash to fund operations into the second quarter of 2028.

Pipeline Progress Across Three Programs

Beyond the BLA filing, Dyne completed enrollment of 71 participants in the registrational expansion cohort of the Phase 1/2 ACHIEVE trial evaluating z-basivarsen (DYNE-101) in myotonic dystrophy type 1, with topline data expected in the first quarter of 2027. The company also initiated the global confirmatory Phase 3 HARMONIA trial for z-basivarsen.

The FDA cleared Dyne's investigational new drug application for DYNE-302, an siRNA candidate for facioscapulohumeral muscular dystrophy, allowing the company to begin Phase 1 studies. Dyne is also advancing preclinical programs in Pompe disease and multiple additional DMD mutations.

Z-rostudirsen (zeleciment rostudirsen, also known as DYNE-251) is an antibody-oligonucleotide conjugate designed to deliver an exon 51-skipping antisense oligonucleotide to muscle cells using the company's FORCE platform. If approved, it would compete with Sarepta Therapeutics' Amondys 45 and other exon-skipping therapies in the DMD market, which affects about one in every 3,500 male births worldwide.

The Priority Review designation shortens the FDA's standard 10-month review to six months, reflecting the agency's view that the drug could offer a significant improvement over available therapy. The Jan. 21 PDUFA date positions Dyne for a potential commercial launch in early 2027, assuming approval. Investors will watch for the FDA's advisory committee meeting, typically scheduled two to three months before the PDUFA date, for an early signal on the agency's thinking.

This article is for informational purposes only and does not constitute investment advice.