NS Pharma, Inc., a subsidiary of Nippon Shinyaku Co., recently announced via news release that its therapy NS-089/NCNP-02 was granted Orphan Drug designation from the U.S. Food and Drug Administration for the treatment of Duchenne muscular dystrophy (DMD) who are amenable to exon 44 skipping therapy.
About Duchenne Muscular Dystrophy (DMD)
There are nine different forms of muscular dystrophy. Duchenne muscular dystrophy is a form that predominantly affects boys. While it can affect girls, it is extremely rare, with only 1 in every 50 million female births having DMD. Duchenne muscular dystrophy is a rare genetic disorder characterized by an inability to make dystrophin, a protein, in the muscles, leading to muscle weakness. Symptoms usually appear before age six and can include:
- Frequent falling
- Muscle weakness that starts in the pelvis, legs, and thighs before progressing elsewhere
- Difficulty walking, climbing stairs, or moving positions
- Learning disabilities
- A waddling gait
- Enlarged calves
- Respiratory failure
- Heart disease
Many people with DMD use wheelchairs and other support by their teenage years. Other treatments include corticosteroids, vitamin supplemental, physical therapy, occupational therapy, assisted breathing, and heart medication. Elevidys was also approved in June 2023; this gene therapy is used to treat children between four and five years old.
What is Exon Skipping and Why Did It Receive Orphan Drug Status?
Parent Project Muscular Dystrophy explains that:
one of the most common types of mutations in the dystrophin gene occurs when a piece of the code in the middle of the gene is missing or deleted. By skipping additional segments of the dystrophin code called exons, the deletion can shift from an out-of-frame deletion to an in-frame deletion [that often] results in a smaller, but still functional, dystrophin protein.
Since this smaller protein still acts like normal dystrophin, researchers hope that NS-089/NCNP-02 can relieve and improve symptoms of DMD. Moving forward, NS Pharma hopes to launch Phase 2 clinical studies in both the United States and Japan.
The treatment’s Orphan Drug designation means that NS Pharma earns incentives such as fee waivers, increased regulatory assistance, and up to seven years of market exclusivity if NS-089/NCNP-02 is approved; these incentives are given as part of this status to incentivize and support drug development and review for rare conditions, or conditions affecting fewer than 200,000 Americans.