Updated findings from the phase 3 KEYNOTE-024 trial show that pembrolizumab (Keytruda, Merck) lowered the risk of death by 37% compared with chemotherapy after two years as first-line monotherapy in patients with non–small-cell lung cancer (NSCLC) whose tumors express high levels of PD-L1. Pembrolizumab increased overall survival (OS) by more than one year.
The results apply to patients with a PD-L1 tumor proportion score [TPS] of 50% or more. The study included patients with squamous and nonsquamous NSCLC with no EGFR or ALK genomic tumor aberrations. Findings based on more than two years of follow-up showed an OS of 30.0 months for pembrolizumab versus 14.2 months for chemotherapy.
“The significant overall survival findings observed in KEYNOTE-024, which includes patients who have a poor prognosis, reinforce the use of Keytruda in appropriate patients in the first-line treatment of this disease,” said Professor Martin Reck, head of the department of thoracic oncology at LungenClinic Grosshansdorf, Germany.
KEYNOTE-024 studied 305 patients with metastatic NSCLC who were assigned either pembrolizumab as monotherapy (n = 154) or standard of care platinum-based chemotherapy (n = 151). Enrollment criteria included: having no prior systemic chemotherapy treatment for their advanced disease, tumors without an EGFR sensitizing mutation or ALK translocation, and tumors expressing high levels of PD-L1 (TPS of 50% or more) as determined by a central laboratory FDA-approved test. The primary endpoint was progression-free survival (PFS) and the key secondary endpoint was OS. Other secondary endpoints include overall response rate (ORR) and safety. Exploratory endpoints include duration of response.
The new data are based on a median follow-up of 25.2 months in 305 patients and include findings from 82 patients who crossed over from the chemotherapy group to receive pembrolizumab, per study protocol, and 12 patients who received anti-PD-1 therapy outside of study crossover, totaling a 62.3% effective crossover rate.
The 24-month OS rate was 51.5% in the pembrolizumab group compared to 34.5% in the chemotherapy group; at 12 months, the OS rate was 70.3% in the pembrolizumab group compared to 54.8% in the chemotherapy group.
The safety of pembrolizumab was consistent with what has been seen in previous trials among patients with metastatic NSCLC.
Source: Merck; October 18, 2017.