Sarepta Therapeutics reported data showing its experimental gene therapy increased expression of a protein missing in limb‑girdle muscular dystrophy 2E (LGMD2E) and said it plans to file for regulatory approval. If cleared, the therapy would be the first approved treatment for a form of LGMD. The company presented biomarker and expression data that it says support a filing; investigators noted the rarity and heterogeneity of LGMD will shape regulatory and post‑approval evidence requirements. Sponsors and regulators will debate endpoints and durable benefit measures for ultra‑rare neuromuscular diseases. LGMD refers to a group of genetic muscle disorders that cause progressive weakness; LGMD2E is one subtype caused by mutations that lead to loss of a specific structural protein in muscle tissue.