The following is a summary of “Pembrolizumab Plus Pemetrexed and Platinum in Nonsquamous Non–Small-Cell Lung Cancer: 5-Year Outcomes From the Phase 3 KEYNOTE-189 Study,” published in the April 2023 issue of Oncology by Garassino, et al.
For a study, researchers presented the 5-year results of the phase III KEYNOTE-189 trial. The trial enrolled untreated patients with metastatic nonsquamous non-small-cell lung cancer without EGFR/ALK alterations, who were randomly assigned 2:1 to receive either pembrolizumab 200 mg or placebo once every 3 weeks for up to 35 cycles, with pemetrexed and investigator’s choice of carboplatin/cisplatin for four cycles, followed by maintenance pemetrexed until disease progression or unacceptable toxicity. The primary endpoints were overall survival (OS) and progression-free survival (PFS).
Among the 616 randomized patients, the median follow-up time from random assignment to data cutoff (March 8, 2022) was 64.6 (range, 60.1-72.4) months. The hazard ratios (95% CI) for OS and PFS were 0.60 (0.50 to 0.72) and 0.50 (0.42 to 0.60), respectively, for pembrolizumab plus platinum-pemetrexed versus placebo plus platinum-pemetrexed. The 5-year OS rates were 19.4% versus 11.3%. The toxicity was manageable. Among 57 patients who completed 35 cycles of pembrolizumab, the objective response rate was 86.0%, and the 3-year OS rate after completing 35 cycles (approximately 5 years after random assignment) was 71.9%.
The results suggested that pembrolizumab plus pemetrexed-platinum continues to be a standard of care in untreated metastatic non-small-cell lung cancer without EGFR/ALK alterations, irrespective of programmed cell death ligand-1 expression.