Phase III KEYNOTE-604 trial of Keytruda plus chemo meets primary endpoint in small cell lung cancer.- Merck Inc

Merck Inc announced that the Phase III KEYNOTE-604 trial investigating Keytruda (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with chemotherapy met one of its dual primary endpoints of progression-free survival (PFS) in the first-line treatment of patients with extensive stage small cell lung cancer (ES-SCLC). In the study, treatment with Keytruda in combination with chemotherapy (etoposide plus cisplatin or carboplatin) resulted in a statistically significant improvement in PFS compared to chemotherapy alone (HR=0.75 [95% CI, 0.61-0.91]), which was observed at a prior interim analysis. At the final analysis of the study, there was also an improvement in overall survival (OS) for patients treated with Keytruda in combination with chemotherapy compared to chemotherapy alone; however, these OS results did not meet statistical significance per the pre-specified statistical plan (HR=0.80 [95% CI, 0.64-0.98]). The safety profile of Keytruda in this trial was consistent with that observed in previously reported studies. Results will be presented at an upcoming medical meeting and discussed with regulatory authorities. KEYNOTE-604 is a randomized, double-blind, placebo-controlled Phase III trial (ClinicalTrials.gov, NCT03066778) investigating Keytruda in combination with chemotherapy compared to chemotherapy alone in patients with newly diagnosed ES-SCLC. The dual primary endpoints were OS and PFS. Secondary endpoints included objective response rate (ORR), duration of response (DOR), safety and quality of life (QoL).