Prime Medicine reversed a prior deprioritization and said it will pursue FDA approval for PM359, a prime‑editing therapy for chronic granulomatous disease (CGD), based on data from just two treated patients. The company expects that recent FDA initiatives around bespoke and small‑cohort pathways could allow a two‑patient dataset, paired with mechanistic rationale, to support accelerated approval. Prime’s move follows agency outreach and new regulatory programs designed to expand options for ultra‑rare and heavily personalized therapies. Company executives said they are working to align final study design and evidence expectations with FDA reviewers before filing. The program’s small eligible population—Prime estimates roughly 50 eligible patients in the U.S.—crystallizes the economic and clinical tradeoffs inherent in developing curative gene‑editing medicines for very rare diseases. The submission will test statutory and policy boundaries around evidentiary standards for gene editing and could set a precedent for other firms with small‑N data packages relying on mechanistic plausibility, natural‑history comparators, and biomarker endpoints.