Daiichi Sankyo (4568): Early approval scenario for I-DXd in the US no longer viable after voluntary withdrawal of BLA

On September 25 (US time), Daiichi Sankyo and Merck voluntarily withdrew the US Biologics License Application (BLA) for ifinatamab deruxtecan (I-DXd) for the treatment of extensive-stage small cell lung cancer (ES-SCLC) in patients with disease progression after platinum-based chemotherapy. This decision followed discussions with the FDA, which determined that the submitted data, including from the IDeate-Lung01 Phase 2 trial, did not meet the requirements for accelerated approval. The PDUFA date for I-DXd had been set for October 10, so the withdrawal came just before the approval decision. This was not a Complete Response Letter (CRL). This has negative implications for Daiichi Sankyo. Daiichi Sankyo's FY2026 guidance for I-DXd sales is ¥3.3 billion. The scenario for early US approval and launch of I-DXd in 2026 is no longer viable. Approval will likely be sought based on the results of the IDeate-Lung02 Phase 3 trial (SCLC, 2L, primary endpoint: OS, primary completion: January 30, 2