Ultragenyx has received an FDA rejection for its experimental gene therapy targeting Sanfilippo syndrome, a rare and fatal pediatric neurodegenerative disorder. The FDA cited concerns over efficacy data, delaying approval for the treatment. The decision is a major setback for families awaiting a one-time gene therapy option to address the root cause of this rare disease. Ultragenyx plans to work with regulators to resolve the issues and continue advancing its gene therapy pip

Sarepta Therapeutics has paused its Duchenne muscular dystrophy (DMD) gene therapy, Elevidys, after a second patient death due to acute liver failure. The pause affects ongoing trials and therapy shipments, raising safety concerns—especially for non-ambulatory patients. Approved under the FDA’s accelerated pathway, Elevidys aimed to slow DMD progression, but recent events have sparked debate over gene therapy risks, regulatory oversight, and treatment decisions for affected f