Prime Medicine reversed course and plans to seek FDA approval for PM359, a prime‑editing therapy for chronic granulomatous disease (CGD), based on outcomes in two treated patients. The company cited recent FDA dialogue and new pathways intended to accelerate individualized and rare‑disease therapies as the basis for pursuing a submission that would test the agency’s flexibility on small, highly selective datasets. Prime’s approach uses prime editing, a CRISPR‑based method that can precisely install small DNA changes; the filing will test how regulators weigh mechanistic plausibility and limited clinical data in ultrarare diseases.