Dyne Therapeutics shares fell after Novartis reported that its global Phase 3 HARBOR study of del-desiran for myotonic dystrophy type 1 (DM1) failed to show a statistically significant improvement over placebo on video hand opening time (vHOT), the trial’s primary endpoint and a measure of hand myotonia. Dyne is developing z-basivarsen, also known as DYNE-101, an antisense oligonucleotide (genetic-targeting drug) linked to an antigen-binding fragment that binds transferrin receptor 1 to deliver treatment to muscle and the central nervous system. The company plans to present additional one-year ACHIEVE data at two medical meetings, while topline data from its blinded registrational expansion cohort are planned for the first quarter of 2027. Dyne has also begun the Phase 3 HARMONIA trial, designed to support traditional U.S. approval and ex-U.S. marketing applications.