Ahead of ASCO 2026, Merck and Kelun Biotech’s sacituzumab tirumotecan (sac-TMT) plus Keytruda delivered a statistically significant progression-free survival improvement in first-line, PD-L1–positive non-small cell lung cancer in China. The OptiTROP-Lung05 abstract reports a major risk reduction for disease progression or death versus Keytruda alone. The interim analysis showed median PFS not reached in the combination arm versus 5.7 months with Keytruda (P<0.0001). A preliminary 45% overall survival improvement trend was observed, with OS results expected later to support regulatory discussions. The data intensify competition among antibody-drug conjugate combinations and other next-generation IO strategies, with a key question now being whether OS will mature in a way that supports a practice-changing label.