FP12.02 Pembrolizumab as a Monotherapy or in Combination With Platinum-Based Chemotherapy in NSCLC: Correlation With Blood Biomarkers

Both pembrolizumab as a monotherapy (P) and a combination with platinum-based chemotherapy (PCT) represent standard 1st-line treatment (Tx) options for advanced NSCLC (aNSCLC) with PD-L1 tumor proportion score (TPS)≥50%. No predictive biomarkers exist to guide Tx decisions. 423 consecutive patients (pts) with EGFR/ALK/ROS1-wild-type PD-L1 TPS≥50% aNSCLC receiving P (group P, n=302) or PCT (group PCT, n=121) as a 1st-line Tx were identified in the electronic databases of 5 Israeli cancer centers. Overall survival (OS) was assessed in correlation with blood biomarkers (BB): NLR, dNLR, PLR, SII, LIPI, ALI. Baseline characteristics were well balanced, except for age (p=0.0001) and ECOG PS (p=0.01) in favor of group PCT. Median OS was 13.8 months (mo) (95% CI, 11.0-18.2) and 21.3 mo (95% CI, 14.8-NR) in groups P and PCT, respectively (p=0.04). In the propensity score matching analysis (n=236; 118 pts in each group matched for age, sex and ECOG PS), mOS was 17.2 mo (95% CI, 13.2-36.5) and 21.3 mo (95% CI, 14.8-NR) in groups P and PCT, respectively (p=0.44). In group P, NLR, dNLR, PLR, LIPI, and ALI, along with age and ECOG PS significantly correlated with OS in uni- and multivariate COX regression analysis, whereas in group PCT, none of the BB demonstrated a significant correlation (a separate multivariate analysis was done for each of the BB; the model included sex, age, histology and ECOG PS - Table). In the whole cohort, OS favored PCT over P in pts≥65 years (p=0.008), females (p=0.008), NLR≥5 (p=0.02), dNLR≥3 (p=0.009), PLR≥169 (p=0.002), SII≥400 (p=0.03), ALI < 18 (p=0.03) and LIPI 1+2 (p=0.001) (Figure).View Large Image Figure ViewerDownload Hi-res image Download (PPT) With the limitations of the retrospective analysis, the selected BB appear to predict outcomes with P and PCT. In order to guide Tx decisions, the results need to be validated prospectively.