Ipsen voluntarily pulled the EZH2 inhibitor Tazverik (tazemetostat) from the U.S. market and halted ongoing clinical studies following independent monitoring that identified secondary hematologic malignancies in a confirmatory trial. The company said it will discontinue development and stop distribution while monitoring patient safety and ensuring standard‑of‑care for trial participants. Tazverik had regulatory approvals in epithelioid sarcoma and follicular lymphoma but faced underwhelming commercial performance. Ipsen’s action follows an independent data monitoring committee finding and represents a rare post‑approval market withdrawal driven by long‑term safety signals. The company has not disclosed the number of secondary malignancy cases but said withdrawal will not materially change near‑term financial guidance. The move will prompt scrutiny of post‑marketing surveillance, confirmatory trial design, and regulatory safety thresholds for oncology agents approved under accelerated pathways.