1138P Alternate pembrolizumab dosing interval in advanced NSCLC with PD-L1 >/= 50%: 3 weekly compared to 6 weekly dosing

Pembrolizumab 200mg every 3 week (Q3W) is the standard of care for patients with advanced non-small cell lung cancer (NSCLC) and PDL1 ≥ 50%. In April 2020, the FDA approved 400 mg every 6 weeks (Q6W) based on pharmacokinetic modeling without formal comparative studies. Pharmacokinetic studies also suggested that weight-based and flat dosing for the respective schedules have comparable target engagement. The objective of this study was to evaluate the overall survival (OS) based on the Q3W versus Q6W pembrolizumab dosing schedule.