Merck announced results from KEYNOTE-189, a pivotal phase III trial evaluating Keytruda (pembrolizumab) in combination with pemetrexed (Alimta) and cisplatin or carboplatin for the first-line treatment of metastatic nonsquamous non-small cell lung cancer.
Findings showed that the Keytruda-pemetrexed-platinum chemotherapy combination significantly improved overall survival (OS), reducing the risk of death by half compared with chemotherapy alone (HR=0.49 [95% CI, 0.38-0.64]; p<0.00001). In pre-specified exploratory analyses, an OS benefit was observed regardless of PD-L1 expression in the three PD-L1 categories that were evaluated, including: patients whose tumors were negative for PD-L1 (HR=0.59 [95% CI, 0.38-0.92]); patients whose tumors had PD-L1 tumor proportion scores (TPS) of 1-49 percent (HR=0.55 [95% CI, 0.34-0.90]); and patients who had a TPS of greater than or equal to 50 percent (HR=0.42 [95% CI, 0.26-0.68]).
The addition of Keytruda to pemetrexed plus platinum chemotherapy also achieved a significant improvement in progression-free survival (PFS), with a reduction in the risk of progression or death of nearly half for patients in the Keytruda combination arm, compared with chemotherapy alone (HR=0.52 [95% CI, 0.43-0.64]; p<0.00001). A PFS improvement in the Keytruda combination group was observed in patients whose tumors were negative for PD-L1 (HR=0.75 [95% CI, 0.53-1.05]); patients with a TPS of 1-49 percent (HR=0.55 [95% CI, 0.37-0.81]); and patients with a TPS greater than or equal to 50 percent (HR=0.36 [95% CI, 0.25-0.52]).
These results are being presented today in a plenary session at the American Association for Cancer Research Annual Meeting, with simultaneous publication in The New England Journal of Medicine.
“In this trial, Keytruda in combination with pemetrexed and platinum chemotherapy, compared with chemotherapy alone, prolonged overall survival and progression-free survival in patients with advanced nonsquamous non-small cell lung cancer regardless of PD-L1 expression,” said Leena Gandhi, director of thoracic medical oncology at NYU Langone’s Perlmutter Cancer Center and lead author of The New England Journal of Medicine paper. “There is good scientific rationale for combining Keytruda with pemetrexed and platinum chemotherapy, and these clinical data now suggest this combination as a new standard of care for the first-line treatment of these nonsquamous non-small cell lung cancer patients.”