Merck and Daiichi Sankyo's Lung Cancer Filing Halted by FDA

Daiichi Sankyo and Merck & Co. have withdrawn their filing for accelerated approval of ifinatamab deruxtecan (I-DXd) in extensive-stage small cell lung cancer (ES-SCLC) after the FDA expressed concerns over the data supporting the application.

The partners had filed for accelerated approval based on results from the phase 2 IDeate-Lung01 study, which enrolled 187 participants with ES-SCLC who were previously treated with at least one prior line of platinum-based chemotherapy.

While the FDA acknowledged the 'promising' efficacy data, they deemed it insufficient to meet the requirements for accelerated approval. In response, Daiichi and Merck voluntarily pulled their filing.

The withdrawal deals another blow to the $4 billion partnership between the two companies, which has disappointed investors so far. The deal was struck in 2023 with Merck paying Daiichi $4 billion upfront to partner on three antibody-drug conjugates (ADCs).