Does pembrolizumab have an effect on prolonging overall survival in patients with non-small cell lung cancer expressing programmed death ligand-1 (PD-L1)?

Objective: The objective of this selective EBM review is to determine whether or not pembrolizumab has an effect on prolonging overall survival in patients with non-small cell lung cancer expressing programmed death ligand-1 (PD-L1). Study Design: Review of two randomized controlled trials and one cohort study published in English in peer review journals. Data Sources: Two randomized controlled trials and one cohort study, which evaluated the efficacy of pembrolizumab on non-small cell lung cancer with PD-L1 expression compared to chemotherapy. All studies were found in PubMed database. Outcomes Measured: Overall survival measured by Kaplan-Meier analysis of overall survival. Results: Both of the RCT (Reck 2016 and Herbst 2016) showed pembrolizumab to be statistically effective in prolonging overall survival in patients with NSCLC expressing PD-L1 (p=0.005 and p\u3c0.0001 respectively). Both studies showed a higher increase in overall survival in patients treated with pembrolizumab compared to those treated with traditional chemotherapy. In the cohort study conducted by Goldberg (2016), overall survival was measured to be 7.7 months (95% CI). Pembrolizumab also showed to have a positive effect on brain metastases as well. Conclusions: All studies included in this systematic review indicate that pembrolizumab is effective in prolonging overall survival in patients with NSCLC expressing PD-L1