Top FDA officials outlined a new regulatory approach—often called the “plausible mechanism” pathway—intended to accelerate approvals for highly individualized gene‑editing therapies. In a perspective published by senior FDA leaders, the agency described criteria under which mechanistic laboratory data, tightly controlled manufacturing and safety monitoring could support authorization for one‑off treatments for ultra‑rare, life‑threatening conditions. The framework builds on the case study of a personalized edit given to a child known as “Baby KJ” and aims to provide a replicable pathway for bespoke edits. Industry and patient groups hailed the clarity, while some experts cautioned about the operational and ethical burdens of scaling bespoke manufacturing and long‑term follow‑up.