Regulatory shifts are impacting the rare disease and gene therapy sectors. The FDA has delayed its decision on Regenxbio’s gene therapy for Hunter syndrome by three months, prolonging uncertainty for this treatment candidate. Additionally, PTC Therapeutics faced a rejection from the FDA for its Friedreich's ataxia drug vatiquinone due to insufficient evidence of efficacy, even as Biogen's Skyclarys remains the sole approved therapy. Stealth BioTherapeutics disclosed an FDA rejection letter for its Barth syndrome drug but resubmitted the application, emphasizing patient reliance on the treatment. On gene therapy front, Kriya Therapeutics secured $313 million in funding to advance its diverse pipeline across neurology, metabolic health, and ophthalmology, underscoring investor confidence despite regulatory challenges. These developments highlight continuing hurdles and momentum in developing therapies for rare and genetic diseases.