PMV Pharmaceuticals published Phase I first‑in‑human data for rezatapopt in the New England Journal of Medicine showing objective responses in heavily pretreated patients with TP53 Y220C‑mutated advanced solid tumors. Seventy‑seven patients were treated across dose‑escalation cohorts; responses were observed across multiple tumor types and biomarker data supported selective binding to the Y220C pocket and restoration of p53 function. Rezatapopt was generally well tolerated, with infrequent dose‑limiting toxicities enabling a recommended Phase II dose. All responding patients carried the TP53 Y220C mutation and were KRAS wild‑type. PMV plans a registrational Phase II strategy and targets a New Drug Application filing in platinum‑resistant/refractory ovarian cancer in early 2027. The NEJM publication establishes clinical proof‑of‑concept for small‑molecule reactivation of a mutant p53 allele and frames rezatapopt as a potential first‑in‑class therapy for a genetically defined subpopulation.