Brogidirsen (NS-089/NCNP-02) 5-Year Clinical Trial Data for the Treatment of Duchenne Muscular Dystrophy Presented at 2026 World Muscle Society Congress

PARAMUS, NJ: October 01, 2026 – NS Pharma, Inc. (Headquarters: Paramus, New Jersey; President: Yukiteru Sugiyama), a biopharmaceutical leader in rare disease and subsidiary of Nippon Shinyaku Co., Ltd. (Headquarters: Kyoto, Japan; President: Toru Nakai), announced today that the National Center of Neurology and Psychiatry (NCNP, Kodaira City; President, Kazuyuki Nakagome) presented 5-year efficacy and safety data from the open-label extension of an investigator-initiated clinical trial of brogidirsen (NS-089/NCNP-02) for the treatment of Duchenne muscular dystrophy (DMD) at the 31^st annual International Congress of the World Muscle Society held in Hiroshima, Japan from September 29 to October 3, 2026.

Brogidirsen is an antisense oligonucleotide co-discovered by Nippon Shinyaku and NCNP as an investigational therapy for DMD patients with dystrophin gene mutations that are amenable to exon 44 skipping.

“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. “It is important for us to continue investigating these therapeutic innovations in hopes of providing patients with additional treatment options and renewed hope.”

The presented data are based on the investigator-initiated clinical trial conducted by NCNP and its extension study conducted by Nippon Shinyaku. These studies evaluated the efficacy and safety of brogidirsen in 6 participants who received weekly IV dosing.

Findings include:

• Maintenance of motor function – Evaluation demonstrated maintenance or improvement of motor function in participants who remained ambulant during the course of the study. Further, upper limb function was maintained in all participants including those who became non-ambulant during the course of the study.
• Acceptable safety profile – After 5 years of receiving brogidirsen, no serious or severe adverse events, or anaphylaxis related to long-term brogidirsen administration, were reported, and there were no discontinuations.
• Comparison to natural history data – In several measures, the observed functional outcomes compared favorably with the natural history of DMD.

These results suggest the potential of brogidirsen to slow DMD disease progression in patients who are amenable to exon 44 skipping. The extension trial is ongoing to investigate the efficacy and safety of long-term administration. Further, a global Phase II study of brogidirsen is being conducted by Nippon Shinyaku and its subsidiary NS Pharma. Learn more at ClinicalTrials.gov.

About Duchenne Muscular Dystrophy (DMD)
Duchenne is a form of muscular dystrophy that occurs primarily in males. It causes progressive weakness and loss of skeletal, cardiac, and respiratory muscles. Early signs of DMD may include delayed ability to sit, stand or walk. There is a progressive loss of mobility, and by adolescence, patients with Duchenne may require the use of a wheelchair. Cardiac and respiratory muscle problems begin in the teenage years and lead to serious, life-threatening complications. For more information, please visit wespeakduchenne.com.

About NS Pharma, Inc.
NS Pharma, Inc., is a wholly owned subsidiary and registered trademark of Nippon Shinyaku Co., Ltd. Backed by over one hundred years of development expertise, NS Pharma is dedicated to delivering life-changing care to people living with complex, rare diseases. For more information, please visit nspharma.com.

US Media Contact: [email protected]