Daiichi Sankyo and Merck paused enrollment and the FDA placed a partial hold on the Phase III IDeate‑Lung02 study of the ADC ifinatamab deruxtecan following a higher‑than‑anticipated incidence of deaths tied to interstitial lung disease (ILD). Daiichi reported the pause and said regulators, the independent data monitoring committee and the companies will review accumulated safety data before deciding next steps. The hold affects multiple European countries and the U.S.; regulators will evaluate whether the safety signal requires protocol changes, additional monitoring, or trial termination. Antibody‑drug conjugates (ADCs) deliver cytotoxins to tumors; ILD has been a known risk classwide for certain ADCs. Sponsors will need to reconcile the risk‑benefit profile, given ADCs’ potency and prior safety precedents.