Phase III KEYNOTE-091 trial of Keytruda improved survival in non-small cell lung cancer.- Merck Inc

The study found that adjuvant treatment with Keytruda (pembrolizumab) significantly improved disease-free survival (DFS), one of the dual primary endpoints, reducing the risk of disease recurrence or death by 24% compared to placebo (hazard ratio [HR]=0.76 [95% CI, 0.63-0.91]; p=0.0014) in patients with stage IB (at least 4 centimeters) to IIIA non-small cell lung cancer (NSCLC) following surgical resection regardless of PD-L1 expression. Median DFS was 53.6 months for Keytruda versus 42.0 months for placebo, an improvement of nearly one year.

There was also an improvement in DFS for patients whose tumors express PD-L1 (tumor proportion score [TPS] at least 50%) treated with Keytruda compared to placebo, the other dual primary endpoint; these results did not reach statistical significance per the pre-specified statistical plan (HR=0.82 [95% CI, 0.57-1.18]; p=0.14). Among these patients, median DFS was not reached in either arm.

Additionally, a favorable trend in overall survival (OS), a key secondary endpoint, was observed for Keytruda versus placebo regardless of PD-L1 expression (HR=0.87 [95% CI, 0.67-1.15]; p=0.17); these OS data are not mature and did not reach statistical significance at the time of this interim analysis. The trial will continue to evaluate DFS in patients whose tumors express high levels of PD-L1 (TPS at least 50%) and OS. The safety profile of Keytruda in this study was consistent with that observed in previously reported studies. These data are being presented during a European Society for Medical Oncology (ESMO) Virtual Plenary and will be shared with regulatory authorities worldwide.