Clinical activity, safety and predictive biomarkers of the engineered antibody MPDL3280A (anti-PDL1) in non-small cell lung cancer (NSCLC): update from a phase Ia study.

8029 Background: NSCLC exhibits mutational complexity, which is associated with increased tumor immunogenicity. PD-L1 expression in the tumor microenvironment can inhibit antitumor immunity. MPDL3280A blocks PD-L1 and can restore tumor-specific T-cell immunity. Methods: In this dose-escalation and -expansion study, pts with NSCLC were enrolled from Oct 25, 2011 to Sep 24, 2013 and received MPDL3280A IV ≤ 20 mg/kg q3w (data cutoff Sep 2, 2014). ORRs were assessed by RECIST v1.1. PD-L1 expression on tumor-infiltrating immune cells (ICs) and tumor cells (TCs) was centrally evaluated by an IHC assay based on the SP142 antibody with pts scored as IC 0, 1, 2 or 3 and TC 0, 1, 2 or 3. Results: 88 NSCLC pts were safety- and efficacy-evaluable: 57% of pts were male, 28% were ECOG PS 0 and 72% were ECOG PS 1. The median age was 61 y (range, 24-84 y), and the majority of pts had 3 lines of therapy. Pts received MPDL3280A for a median duration of 15 wks (range, 0-129 wks). Treatment-related all grade AEs occurred in ...