The FDA accepted and granted priority review to Daiichi Sankyo and Merck for ifinatamab deruxtecan, a B7-H3-directed antibody-drug conjugate being evaluated for advanced extensive-stage small-cell lung cancer. The decision moves the program faster through the review pathway as the agencies assess safety and efficacy data. For oncology development teams, priority review status often signals strong alignment on clinical endpoints and increases the odds of earlier market access for therapies in fast-progressing disease settings. The milestone also adds momentum to the B7-H3 ADC space as regulators evaluate antigen-directed strategies aimed at difficult-to-treat lung cancer subtypes.