FDA grants RAG-18 orphan drug designation for Duchenne and Becker muscular dystrophy

The FDA has granted orphan drug designation to RAG-18 (Ractigen Therapeutics) as a potential new therapeutic for Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), which are caused by a mutation in the DMD gene. This follows the drug's designation as a rare pediatric disease in July 2024.¹

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“The granting of FDA orphan drug designation is a critical achievement for RAG-18. Together with the recent pediatric rare disease designation, this reflects the groundbreaking work we are doing in the field of RNA activation and reinforces our commitment to truly improving the lives of people affected by rare diseases,” said Dr. Long-Cheng Li, founder and CEO of Ractigen Therapeutics, in a press release.¹ This recognition reinforces our determination to advance the development of RAG-18 with the goal of bringing innovative and life-changing treatments to DMD and BMD patients around the world.”

DMD is a genetic disorder that causes degeneration and weakness of muscles and affects the dystrophin protein. It is considered the most severe form of dystrophinopathies. The disease usually begins between the ages of 2 and 3, with boys most commonly affected, but girls can also be affected. According to the National Library of Medicine, the prevalence of DMD in the United States is 2 per 10,000 people.^2.3

BMD is considered similar to DMD, but the voluntary muscles affected function better than in DMD. In addition, BMD occurs between the ages of 5 and 60 and progresses more slowly and less predictably. According to the National Library of Medicine, the prevalence of BMD for all ages was 0.26 per 10,000 men in 2010.^4.5

RAG-18 is the first-of-its-kind self-amplifying RNA candidate that targets and activates UTRN gene expression in muscle cells. The protein for the gene is similar to dystrophin, so upregulating it could potentially replace the functional components of missing DMD muscle cells. Preclinical data showed that the drug alleviated muscle damage and has the potential to treat DMD and BMD.¹

REFERENCES

1. Ractigen Therapeutics Announces U.S. FDA Orphan Drug Designation (ODD) for RAG-18 for the Treatment of Duchenne Muscular Dystrophy and Becker Muscular Dystrophy. Press release. Ractigen Therapeutics. August 22, 2024. Retrieved August 22, 2024. https://prnmedia.prnewswire.com/news-releases/ractigen-therapeutics-announces-us-fda-orphan-drug-designation-odd-granted-to-rag-18-for-the-treatment-of-duchenne-muscular-dystrophy-and-becker-muscular-dystrophy-302228550.html

2. The Muscular Dystrophy Association. Duchenne muscular dystrophy (DMD). Retrieved August 22, 2024. https://www.mda.org/disease/duchenne-muscular-dystrophy

3. Venugopal V, Pavlakis S. Duchenne muscular dystrophy. [Updated 2023 Jul 10]In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available at: https://www.ncbi.nlm.nih.gov/books/NBK482346/

4. The Muscular Dystrophy Association. Becker muscular dystrophy (BMD). Retrieved August 22, 2024. https://www.mda.org/disease/becker-muscular-dystrophy

5. Thada PK, Bhandari J, Forshaw KC, et al. Becker muscular dystrophy. [Updated 2024 Jan 30]In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available at: