Merck and Daiichi Sankyo Withdraw Accelerated Approval Application for Small Cell Lung Cancer Drug

Pharmaceutical giants Merck & Co., Inc. (NYSEMRK) and Daiichi Sankyo (TYO4568) have withdrawn their joint accelerated approval application for ifinatamab deruxtecan, a small cell lung cancer drug.

The US Food and Drug Administration (FDA) had granted the application priority review in April with an action date of October 10, 2026. However, after discussions with the FDA, Merck and Daiichi Sankyo concluded that their supporting data did not meet the agency's requirements for accelerated approval.

The biologics license application was seeking treatment for adults whose extensive-stage small cell lung cancer had progressed on or after platinum-based chemotherapy. The companies are continuing to enroll patients in a Phase 3 trial, IDeate-Lung02, which compares ifinatamab deruxtecan with physicians' choice of amrubicin, lurbinectedin, or topotecan.

Merck and Daiichi Sankyo are also studying the drug in Phase 3 trials for prostate and esophageal cancers. Amgen Inc. (NASDAQAMGN) has already received full approval from the FDA for its Imdelltra treatment in the same setting.