A closely watched phase 3 trial in PD-L1–high metastatic lung cancer delivered a setback for an antibody-drug combination strategy. Sacituzumab govitecan, an antibody-drug conjugate, failed to show a statistically significant improvement in progression-free survival when added to pembrolizumab versus the trial’s comparator approach. The outcome is significant because A(DC) + checkpoint inhibitor combinations have been a central hypothesis for improving depth and durability of responses in non-small cell lung cancer. The negative PFS signal also highlights the difficulty of converting multi-tumor ADC signals into consistent benefit in specific biomarker-defined subsets. Developers will likely reassess patient selection, sequencing, and endpoints beyond PFS in similar future efforts. For clinicians, the data restrict the use-case for this regimen in PD-L1 high disease based on this trial’s results. (Story coverage source: clinical trial report.)