Perioperative Pembrolizumab in Japanese Participants With Early-Stage NSCLC: Subgroup Analysis From KEYNOTE-671

The global KEYNOTE-671 (clinicaltrials.gov: NCT03425643) study demonstrated significantly improved survival with perioperative pembrolizumab plus neoadjuvant chemotherapy versus neoadjuvant chemotherapy alone in early-stage non-small-cell lung cancer (NSCLC). We present findings from Japanese participants from KEYNOTE-671.

Eligible participants (≥18 y) with previously untreated stage II, IIIA, or IIIB (N2) NSCLC were randomized 1:1 to neoadjuvant pembrolizumab 200 mg or placebo plus cisplatin-based chemotherapy every 3 weeks for up to 4 cycles followed by surgery and adjuvant pembrolizumab or placebo for up to 13 cycles (approximately 9 mo). Primary endpoints were event-free survival (EFS) and overall survival (OS).

Among 82 participants enrolled in Japan, 39 were randomized to pembrolizumab and 43 to placebo. Median time from randomization to database cutoff (August 19, 2024) was 52.7 (range, 32.7-74.9) months. The 48-month EFS rates (95% confidence intervals [CIs]) were 60.3% (42.8%-74.0%) and 39.2% (24.8%-53.4%), respectively, and the EFS hazard ratio was 0.54 (95% CI: 0.29-1.02). For OS, 48-month rates (95% CIs) were 79.5% (63.1%-89.2%) and 68.9% (52.4%-80.7%), and the OS hazard ratio was 0.76 (95% CI: 0.33-1.78). Grade 3 or higher treatment-related adverse events occurred in 23 participants (59%) treated with pembrolizumab and 20 participants (47%) with placebo; there were no deaths due to treatment-related adverse events.

Perioperative pembrolizumab plus neoadjuvant chemotherapy improved efficacy versus neoadjuvant chemotherapy alone and had manageable safety in Japanese participants enrolled in KEYNOTE-671, supporting the use of perioperative pembrolizumab in Japanese patients with early-stage NSCLC.