A joint UCL–UCLA gene therapy program reported multi‑year follow‑up data showing a gene therapy for ADA‑SCID restored immune function in treated children with a 95% success rate and no major safety concerns, according to authors and coverage in The New England Journal of Medicine. The data support claims of a durable, potentially curative effect for this rare pediatric immune deficiency. Researchers involved in the Baby KJ bespoke CRISPR case have published interactions with the FDA to guide others pursuing individualized gene‑editing treatments. The documents outline regulatory considerations, clinical protocols, and safety monitoring for bespoke therapeutics, offering a template for navigating the agency’s emerging pathway for one‑off or highly personalized genetic medicines. Combined, the milestone and regulatory transparency mark a potential inflection point for rare‑disease gene editing—balancing accelerated clinical promise with complex safety and approval challenges.