ESMO 2016: Pembrolizumab Bests Chemotherapy for First-Line Lung Cancer Treatment

Adding pembrolizumab (Keytruda) to first-line chemotherapy improves response and survival rates among patients with previously-untreated advanced PD-L1-positive non-small cell lung cancer (NSCLC), according to findings from the phase III KEYNOTE-024 trial. The findings were presented at the European Society for Medical Oncology (ESMO) Congress, held October 7-11, 2016, in Copenhagen, Denmark, and were published in TheNew England Journal of Medicine.

The findings set the stage for pembrolizumab’s use as a first-line treatment for this patient population. It is currently approved by the US Food and Drug Administration as a second-line therapy.

“In patients with advanced NSCLC and PD-L1 expression on at least 50% of tumor cells, pembrolizumab was associated with significantly longer progression-free and overall survival and with fewer adverse events than was platinum-based chemotherapy,” reported lead study author Martin Reck, MD, PhD, chief oncology physician at the German Center of Lung Research in Grosshansdorf, Germany, and coauthors.

Between 27% and 30% of patients with NSCLC harbor tumors expressing high levels of the programmed cell death ligand 1 (PD-L1), Dr. Reck noted. Pembrolizumab is a humanized antibody immune checkpoint blockade immunotherapy.

A total of 305 patients in 16 countries were randomly assigned (1:1) to receive either a platinum-based chemotherapy or pembrolizumab at the fixed dose of 200 mg every 3 weeks. Patients in the pembrolizumab group had a median progression-free survival (PFS) of 10.3 months, compared to 6.0 months for the chemotherapy group (hazard ratio [HR] for death, 0.50; 95% CI, 0.37-0.68, P < .001).

“The estimated rate of overall survival [OS] at 6 months was 80.2% in the pembrolizumab group versus 72.4% in the chemotherapy group” (HR, 0.60; 95% CI, 0.41-0.89; P = .005),” the coauthors reported.

Response rates were higher among patients administered pembrolizumab than chemotherapy (44.8% vs 27.8%), and median duration of response was longer (not reached vs 6.3 months).

Treatment-related adverse events occurred in 73.4% of pembrolizumab-group patients (grade 3+: 26.6%), and 90% of patients receiving chemotherapy (grade 3+: 53.3%).

The findings “may establish a new standard of care for previously untreated patients with NSCLC and a PD-L1 tumor proportion score of 50% or greater,” noted authors of an editorial by Bruce E. Johnson, MD, published alongside the study.

KEYNOTE-024 was funded by Merck.