Dr. Stinchcombe on the KEYNOTE-189 Trial in Lung Cancer

Thomas E. Stinchcombe, MD, professor of medicine, Duke Cancer Institute, discusses the KEYNOTE-189 trial in patients with lung cancer.

The KEYNOTE-189 trial builds upon cohort G of the KEYNOTE-21 trial, which was a phase II trial that randomized patients to carboplatin/pemetrexed alone or carboplatin/pemetrexed with pembrolizumab (Keytruda). The phase II trial showed a robust response rate, progression-free survival (PFS), and a trend toward overall survival (OS). According to Stinchcombe, the phase III trial met the statistically significant improvement in PFS and OS. This serves as a confirmatory study to the promising results observed in the phase II trial.

In the experimental arm, patients received pembrolizumab at a 200 mg fixed dose every 3 weeks plus 500 mg/m² of pemetrexed plus either 75 mg/m² of cisplatin or carboplatin on day 1 every 3 weeks for 4 cycles, followed by 200 mg of pembrolizumab plus 500 mg/m² of pemetrexed every 3 weeks. The regimen administered to the control group was identical, except that pembrolizumab was replaced with placebo.

As for other combinations being developed with immunotherapy, the one that is furthest in development is the trial of carboplatin, paclitaxel, and bevacizumab (Avastin) alone or with atezolizumab (Tecentriq). This comparison was seen in a 3-arm trial showing promising improvement in response and a statistically significant improvement in PFS. The OS data are immature at this time.