Dr Oselin on a Subgroup Analysis of the PEARLS/KEYNOTE-091 Trial in NSCLC

Kersti Oselin, MD, PhD, medical oncologist, North-Estonian Regional Hospital Cancer Center, discusses a subgroup analysis from the phase 3 PEARLS/KEYNOTE-091 study (NCT02504372) of pembrolizumab (Keytruda) in patients with early-stage non‒small-cell lung cancer (NSCLC) following resection.

The randomized, triple-blind phase 3 study evaluated adjuvant pembrolizumab vs placebo in patients with completely resected stage IB to stage IIIA NSCLC. Patients were allowed to receive adjuvant chemotherapy prior to randomization, and the subgroup analysis examined outcomes of those patients who underwent adjuvant chemotherapy. Of the 1177 in the intent-to-treat population, 1010 patients received adjuvant chemotherapy, including 506 in the pembrolizumab arm and 504 in the placebo arm.

The median disease-free survival (DFS) was 58.7 months (95% CI, 39.2–not reached [NR]) for patients who received pembrolizumab vs 34.9 months (95% CI, 28.6-NR) for those who received placebo (HR, 0.73; 95% CI, 0.60-0.89). The DFS benefit was observed for pembrolizumab vs placebo across different subgroups of patients who received adjuvant chemotherapy, including PD-L1 expression level, stage, age, gender, and histology, Oselin says.

Oselin points out that the study was initiated in 2015, and testing for EGFR mutations was conducted only on a small subset of patients. Although the subgroup analysis showed that this small subset of EGFR-positive patients experienced a benefit with pembrolizumab vs placebo, Oselin concludes that she would not suggest that patients harboring EGFR mutations should receive immunotherapy.