Real-world survival outcomes of patients with high PD-L1 advanced NSCLC who received chemoimmunotherapy versus immunotherapy

Background: Randomized studies have demonstrated superior overall survival (OS) of pembrolizumab (pembro), both alone and in combination with chemotherapy (chemo) over chemo alone in patients with programmed cell death ligand-1 (PD-L1) ≥ 50% advanced non–small cell lung cancer (NSCLC). We reviewed the real-world outcomes of patients who received pembro-chemo versus pembro only.

Methods: This Australian-based retrospective cohort study used data from patients with advanced NSCLC PD-L1 ≥ 50%, diagnosed between January 2016 and July 2021 and had received first-line pembro-chemo or pembro only. Patients with an EGFR/ALK/ROS1 sensitizing mutation were excluded. Cox proportional-hazards model and Kaplan–Meier methods were used to estimate OS and progression-free survival (PFS).

Results: Of 111 eligible patients, 25 received pembro-chemo and 86 received pembro only. After a median follow-up of 15.7 months, median (95% CI) OS was not reached in the pembro-chemo group versus 15.6 (9.5–21.7) months in the pembro-only group (HR 0.57, 95% CI 0.28–1.16, p = 0.12). Median PFS was 12.4 (6.5–18.3) versus 9.5 (6.3–12.6) months in pembro-chemo versus pembro-only groups, respectively (HR 0.62, 95% CI 0.32–1.18, p = 0.18). Objective response rate (ORR) was higher in the pembro-chemo group (60% vs. 30.3%). There were more hospitalizations in the pembro-chemo group versus pembro-only group, 28% versus 18.6%, but immune-related adverse events were similar (32% vs. 32.6%).

Conclusion: In patients with PD-L1 ≥ 50% advanced NSCLC, addition of chemo to first-line pembro yielded a higher ORR but no additional benefit in PFS or OS, supporting a shared-decision approach. However, higher rates of hospitalizations seen in the pembro-chemo group should warrant caution in use.