FDA Grants Orphan Drug Designation to RAG-18 for Duchenne, Becker Muscular Dystrophy

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

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"Receiving FDA Orphan Drug Designation marks a pivotal achievement for RAG-18. Combined with the recent rare pediatric disease designation, it reflects the groundbreaking work we're doing with RNA activation and reinforces our commitment to making a real difference in the lives of those affected by rare diseases,” Long-Cheng Li, MD, founder and CEO of Ractigen Therapeutics, said in a news release.¹ This recognition fuels our determination to push forward with RAG-18's development, aiming to bring innovative and life-changing treatments to DMD and BMD patients around the world."

DMD is a genetic disorder that causes degeneration and weakness of the muscles, effecting the dystrophin protein. It is considered the most severe form of dystrophinopathies. Onset of disease usually occurs between ages 2 and 3, with males being most affected, but can affect females. According to the National Library of Medicine, DMD has a prevalence of 2 per 10,000 individuals in the United States.^2,3

BMD is considered similar to DMD, however, the voluntary muscles that are affected function better than they do for DMD. Additionally, the onset of BMD varies from ages 5 to 60 years, with a slower and less predictable course. The prevalence of BMD for all age ranges was 0.26 per 10,000 male individuals in 2010, according to the National Library of Medicine.^4,5

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

REFERENCES

1. Ractigen Therapeutics Announces US FDA Orphan Drug Designation (ODD) granted to RAG-18 for the treatment of Duchenne Muscular Dystrophy and Becker Muscular Dystrophy. News release. Ractigen Therapeutics. August 22, 2024. Accessed 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). Accessed 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 from: https://www.ncbi.nlm.nih.gov/books/NBK482346/

4. The Muscular Dystrophy Association. Becker Muscular Dystrophy (BMD). Accessed 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 from: https://www.ncbi.nlm.nih.gov/books/NBK556092/