Abstract 1306P
Background
PD-1 / PD-L1 inhibitors have shown efficacy for advanced NSCLC and are now standard therapies for patients(pts) with advanced NSCLC. It is unknown whether pembrolizumab monotherapy (MONO) or pembrolizumab plus chemotherapy (COMB) should be selected for pts exhibiting high PD-L1 expression (TPS of ≥50%). However, there are few reports on the current status of first-line treatment with pembrolizumab for highly PD-L1 expressing NSCLC in clinical practice.
Methods
This study was a retrospective, multicentre study of pts with NSCLC who received MONO or COMB as first-line treatment between December 2018 and January 2020. We reviewed the medical records of 300 pts with advanced-stage or recurrent NSCLC having PD-L1 TPS of ≥50% and no documented EGFR, ALK, or ROS1 aberrations. To control the unbalanced conditions between the two groups at baseline, we implemented a 1:1 propensity score-matched pairing method using age, PS, and PD-L1 status as adjustment factors, and the 1:1 matching yielded matched pairs of 80 pts each.
Results
One hundred and sixty-six pts (55%) received MONO and 134 pts (45%) received COMB. The median ages were 74 (52-89) and 68 (45-84) years (p < 0.01), and the pts of COMB had better PS (0–1) (p < 0.01). With a median follow-up time of 10.6 months (0.1–20.6), the median PFS was 7.1 months (95% CI, 5.4–11.1) and 13.1 months (95% CI, 10.2– NR) (hazard ratio, 0.64; 95% CI, 0.38–1.1). In selected subgroup analysis, the PFS benefit of COMB was observed in the population with PD-L1 TPS of ≥90% and age <75 years. Meanwhile, in the pts with PS 2, PFS was shorter in COMB than MONO. ORR were 42.2% (70/166) and 67.9% (91/134). Treatment discontinuation for any reason occurred in 78% (129/166) and 63% (84/134). Regarding severe adverse events, 21.7% (36/166) and 20.1% (28/134). After propensity score matching, the median PFS was 12.4 months (95% CI, 6.2–NR) and 13.0 months (95% CI, 6.6–17.1).
Conclusions
Based on this real-world cohort, we believe that COMB may be a suitable first-line treatment for highly PD-L1 expressing NSCLC considering that COMB was not inferior to MONO in the propensity score matching analysis, and MONO may be used depending on a patient's background, such as age and PS.
Clinical trial identification
UMIN00040223.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.