Five-year data from six DMD patients show maintained or improved motor function with brogidirsen, with upper-limb function maintained across participants.
Written By: Saniya Katakdhond, PharmD
Reviewed By: Pharmacally Editorial Team
Nippon Shinyaku announced five-year efficacy and safety data for brogidirsen (NS-089/NCNP-02), an investigational antisense oligonucleotide being developed for patients with Duchenne muscular dystrophy (DMD) whose dystrophin gene mutations are amenable to exon 44 skipping.
The findings were presented by the National Center of Neurology and Psychiatry (NCNP) at the 31st International Congress of the World Muscle Society, held in Hiroshima, Japan, from September 29 to October 3, 2026. The data came from an investigator-initiated clinical trial conducted by NCNP and its ongoing open-label extension study conducted by Nippon Shinyaku.
Five-Year Evaluation of Brogidirsen
The studies evaluated the efficacy and safety of weekly intravenous brogidirsen in six patients with DMD. Brogidirsen is an antisense oligonucleotide co-discovered by Nippon Shinyaku and NCNP for patients with dystrophin gene mutations amenable to exon 44 skipping.
The long-term findings were presented in a poster titled “Brogidirsen 5-Year Safety and Efficacy Outcomes in Duchenne Muscular Dystrophy Patients: Findings from an Ongoing Open-Label Extension Study.”
Motor Function Maintained Over Five Years
The efficacy evaluation showed maintenance or improvement of motor function among participants who remained ambulant during the study. Motor function was assessed using measures including the North Star Ambulatory Assessment (NSAA).
Upper-limb function was also maintained across all participants, including those who became non-ambulant during the course of the study. This distinction is important because the five-year findings do not indicate that all six participants remained ambulant throughout the evaluation.
The findings therefore provide longer-term clinical data on functional outcomes following weekly brogidirsen administration, while the ongoing extension study continues to evaluate the treatment over a longer period.
Five-Year Safety Findings
The long-term evaluation also reported safety findings following weekly intravenous administration of brogidirsen.
After five years of treatment, no serious or severe adverse events related to brogidirsen were reported. There were also no infusion-related reactions such as anaphylaxis and no discontinuations due to adverse events among the six patients evaluated in the investigator-initiated trial and its extension study.
These findings are consistent with the earlier long-term development experience with brogidirsen, although the small number of participants limits the ability to characterize less common adverse events. The current five-year findings should therefore be interpreted within the context of the six-patient, ongoing extension study.
Continued Clinical Development
The open-label extension study remains ongoing to further investigate the efficacy and safety of longer-term brogidirsen administration. Nippon Shinyaku and its subsidiary, NS Pharma, are also conducting a global Phase II study of brogidirsen.
Nippon Shinyaku’s current clinical-development information identifies the Phase II study as NS089/NCNP02-201 (NCT05996003) and the Phase II open-label extension study as NS089/NCNP02-P2OE (NCT05135663).
The earlier Phase I/II program enrolled six ambulant patients with DMD amenable to exon 44 skipping, providing the clinical foundation for the ongoing extension evaluation.
Five-Year Data Support Continued Evaluation of Brogidirsen in DMD
Five-year data from six patients receiving weekly intravenous brogidirsen showed maintenance or improvement of motor function among participants who remained ambulant, while upper-limb function was maintained across all participants, including those who became non-ambulant. No serious or severe adverse events related to brogidirsen, infusion-related reactions such as anaphylaxis, or discontinuations due to adverse events were reported.
Nippon Shinyaku said the findings suggest that brogidirsen may have the potential to slow disease progression in patients with DMD whose mutations are amenable to exon 44 skipping. However, the five-year findings come from a small, ongoing clinical program without a concurrent control group, making larger and longer-term studies important for establishing the treatment’s clinical efficacy and durability.
The ongoing extension study and global Phase II program will provide additional data on the longer-term efficacy and safety of brogidirsen in DMD.
Reference
Five-Year Clinical Trial Data for Brogidirsen (NS-089/NCNP-02), an Investigational Treatment for Duchenne Muscular Dystrophy, Presented at the World Muscle Society 2026 Congress, Nippon Shinyaku, 01 October 2026
Exploratory Study of NS-089/NCNP-02 in DMD, ClinicalTrials.gov ID NCT04129294
About the Writer
Saniya Sanjay Katakdhond (Linkedin) is a Doctor of Pharmacy professional with hands-on experience in patient case review, clinical documentation, medical record analysis, and patient care.
Her hospital experience has strengthened her understanding of clinical conditions, treatment approaches, and multidisciplinary healthcare practices.
With ICH-GCP certification and a research-oriented approach, she brings clinical insight and attention to detail to healthcare content development.
As a healthcare writer, Saniya focuses on translating clinical knowledge and patient-care experience into clear, accurate, and evidence-informed medical content.