Lantheus resets FTC review clock for Curium merger without changing closing target

Lantheus is a radiopharmaceutical company centered on radiodiagnostics such as PYLARIFY, DEFINITY, Neuraceq and the newly approved TAUKLARIFY, while transitioning toward a Curium-owned structure. The filing changes the merger timetable mechanically, not economically. Curium withdrew its HSR filing on September 17 and resubmitted it on September 21, restarting a 30-day antitrust waiting period that expires October 21, 2026. 〔0〕

This is a procedural delay signal, not a disclosed regulatory setback. The companies explicitly describe withdrawal and refiling as routine and retain their expectation of closing in the first half of 2027, subject to FTC clearance, the shareholder vote and other closing conditions. 〔1〕 The important distinction is that the FTC review remains active; the filing does not say whether regulators have identified substantive concerns or will request additional information. 〔2〕

Bottom line: This mostly confirms the previously announced Curium acquisition while adding a fresh antitrust-review checkpoint. It matters for timing and execution risk, but the filing provides no new evidence that the transaction’s commercial terms or expected first-half 2027 closing window have changed.