The FDA has pushed back the decision on the experimental gene therapy for Duchenne Muscular Dystrophy (DMD) until June 22. The decision was expected to be made on May 29th, but the FDA pushed it back to complete the review. On May 12, 2022, the FDA Advisory committee voted 8-6 in support of accelerated approval of SRP-9001.
Once approved, it would be available to children 4-5 years of age who have confirmed genetic diagnosis of DMD and are able to walk. SRP-9001 is expected to be beneficial for a small number of patients with the DMD mutations within exons 18-44 or 46-79.
DMD occurs in one of every 3,500 males world-wide. DMD is caused by mutations on the X chromosome, the dystrophin gene. This gene carries regulates the production of making the protein dystrophin. The mutations disrupt the protein’s production. Muscles need dystrophin in order to regenerate, stabilize and protect muscle fibers. The noticeable onset of weakness usually occurs between 2-3 years. Loss of ambulation occurs between age 7-13 years leading to wheelchair dependence. Over time weakness will progress to distal limbs and upper body. Additional signs are frequent trips or falls, abnormal gait, muscle pain or cramps, cognitive and behavioral issues including ASD and ADHD. Overall growth is slower resulting in short stature or hypogonadism. Wheelchair-bound children almost always have evidence of scoliosis with poor pulmonary function. Almost all children will eventually present with cardiac dysfunction. Life expectancy is in the 20s, although with new treatment options, some will live into the 30s and 40s.
Article by Kathy Clark, RN, BSN, CMCN, Vice President, Director of Managed Care. For more information about how this may affect your plan, please contact your Summit ReSources care specialist. The following sources were used as reference material for this article:
https://musculardystrophynews.com/news/decision-dmd-treatment-srp-9001-pushed-back-june/
https://rarediseases.org/rare-diseases/duchenne-muscular-dystrophy/
Advanced Medical Strategies, PredictDx.