Paramus, N.J. – October 01, 2026 -- NS Pharma, Inc. reported 5-year efficacy and safety data showing its investigational therapy brogidirsen maintained or improved motor function in Duchenne muscular dystrophy (DMD) patients amenable to exon 44 skipping, with zero treatment discontinuations across the study period.
Six-participant trial records no serious adverse events over five years
The data, presented by Japan's National Center of Neurology and Psychiatry (NCNP) at the 31st annual International Congress of the World Muscle Society in Hiroshima, Japan, covered an open-label extension of an investigator-initiated clinical trial. All six participants received weekly intravenous dosing of brogidirsen (NS-089/NCNP-02), an antisense oligonucleotide co-discovered by Nippon Shinyaku and NCNP. After five years of administration, no serious or severe adverse events, anaphylaxis, or discontinuations tied to long-term dosing were recorded.
Upper limb function preserved even after loss of ambulation
Participants who remained ambulant during the trial maintained or improved motor function, while upper limb function was preserved in all six participants, including those who became non-ambulant over the course of the study. Researchers noted that functional outcomes compared favorably against DMD natural history data on several measures.
Nippon Shinyaku advances global Phase II study following extension results
"We are excited by the longer-term data demonstrating the potential for brogidirsen to slow disease progression in DMD patients amenable to exon 44 skipping," said NS Pharma President Yukiteru Sugiyama, Ph.D. The extension trial, now run by Nippon Shinyaku following the initial NCNP-led study, continues to track long-term efficacy and safety. Nippon Shinyaku and its U.S. subsidiary NS Pharma are separately conducting a global Phase II study of brogidirsen, with trial details listed on ClinicalTrials.gov.