Population-based study of real-world outcomes of pembrolizumab-chemotherapy for metastatic non-small cell lung cancer in Australia

A retrospective, population-based cohort study in Australia investigated real-world outcomes of adult patients with metastatic non-small cell lung cancer (mNSCLC) initiating first-line pembrolizumab plus chemotherapy between January 1, 2019, and June 30, 2023, consistent with KEYNOTE-189 and KEYNOTE-407 trial regimens. Among 4782 patients (KEYNOTE-189: n=3638; KEYNOTE-407; n=1144), median overall survival was 13.8 months in the KEYNOTE-189 cohort and 12.0 months in the KEYNOTE-407 cohort. Female patients had significantly longer OS than males in both cohorts. Median time to treatment discontinuation did not differ significantly by age or sex. Levothyroxine initiation, used as a proxy for thyroid-related immune-related adverse events (irAEs), was more frequent among female patients in both cohorts. The authors conclude that in this study, real-world survival was shorter than in clinical trials. The observed sex-based differences in survival and irAE proxies suggest potential biological variation in immune checkpoint inhibitor response and toxicity.