Phase II/III results demonstrate impact of PD-L1 expression on efficacy of Keytruda (pembrolizumab) in non small cell lung cancer- Merck Inc

Merck Inc has announced new data, including updated response rates, progression-free survival (PFS) and overall survival (OS) with Keytruda (pembrolizumab), as a monotherapy in patients with advanced non-small cell lung cancer (NSCLC) whose tumors express PD-L1. A sub-analysis from the phase II/III KEYNOTE-010 trial includes OS data with Keytruda compared to chemotherapy in previously treated patients with advanced NSCLC based on varying levels of PD-L1 expression; other data from KEYNOTE-010 are currently under review by the FDA and are intended to serve as the basis for the full approval of Keytruda in lung cancer in patients whose tumors express PD-L1.

Results showed that the OS, PFS, and overall response rate (ORR) generally increased with increasing levels of PD-L1 expression in those patients treated with Keytruda, but not chemotherapy (docetaxel) – with the longest OS and PFS and highest ORR observed in patients who were in the highest PD-L1 TPS category. In patients treated with Keytruda , median OS was 16.6 months in patients in the highest PD-L1 TPS category and 9.7 months in patients in the lowest PD-L1 TPS category; median PFS was 6.2 months in patients in the highest PD-L1 TPS category and 2.6 months in the lowest PD-L1 TPS category; ORR was 33.7 percent in patients in the highest PD-L1 TPS category and 8.6 percent in the lowest PD-L1 TPS category.

In patients treated with chemotherapy, median OS was 8.2 months in patients in the highest PD-L1 TPS category and 8.5 months in patients in the lowest PD-L1 TPS category median PFS was 4.0 months in patients in the highest PD-L1 TPS category and 4.0 months in the lowest PD-L1 TPS category ORR was 7.0 percent in patients in the highest PD-L1 TPS category and 10.9 percent in the lowest PD-L1 TPS category. The safety profile of Keytruda was consistent with that observed in previously reported studies. The findings are being presented at ASCO.

Comment: Keytruda is currently indicated in the U.S. for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 as determined by an FDA-approved test with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving Keytruda (pembrolizumab).