Daiichi Sankyo and Merck voluntarily withdrew their BLA for ifinatamab deruxtecan (i-dxd) targeting B7-H3 in extensive-stage small-cell lung cancer after FDA pushback on the evidentiary basis for accelerated approval. The decision removes a regulatory path they pursued with competing ADCs in an oncology segment marked by fast-moving trial readouts. The withdrawal signals a pause in development momentum for the program in the requested population and highlights how FDA evidence thresholds can shift after data review. The setback may also affect resource allocation across the companies’ ADC portfolios.