e20708 Background: ABP 215 (MVASI™ [bevacizumab]) is the first biosimilar to Avastin (bevacizumab) approved in the US and EU. This phase 3, double-blind study compared efficacy of ABP 215 with bevacizumab reference product (RP) in patients with advanced non-squamous NSCLC. Here we report the totality of evidence supporting similarity between ABP 215 and RP, including preclinical VEGF-A isoform binding relevant to the mechanism of action across indications, and clinical results of central and investigator evaluation of tumor response. Methods: VEGF-A kinetic parameters were compared for common isoforms 121, 165 and 189. Patients were randomized 1:1 to ABP 215 or RP 15 mg/kg Q3Wx6 cycles. All patients received carboplatin and paclitaxel Q3W for up to 6 cycles. Disease assessments (CT/MRI) were performed at screening, weeks 7, 13, 19, and Q9W thereafter by the investigator and, independently, by central, blinded radiologists. Efficacy was based on objective tumor assessments according to RECIST 1.1. Copies of all radiographs were submitted for central analysis. The primary efficacy endpoint was risk ratio of objective response rate (ORR); clinical equivalence was confirmed if the 2-sided 90% CI of the risk ratio was within the margin of 0.67-1.5. Additional efficacy analyses included duration of response (DOR) and progression-free survival (PFS). Results: Binding to all 3 isoforms was similar for ABP 215 and RP. In the MAPLE study, 642 patients (ABP 215, 328; RP, 314) were randomized. Based on central analysis, ORR was achieved in 128 (39.0%) patients in the ABP 215 and 131 (41.7%) in the RP groups, (ORR risk ratio: 0.93 [90% CI: 0.80, 1.09]). Based on investigator analysis, ORR was achieved in 157 (47.9%) patients in the ABP 215 and 151 (48.1%) in the RP groups (ORR risk ratio: 1.01 [90% CI: 0.88, 1.16]). Hazard ratio (HR, ABP 215 vs RP) for DOR was 1.08 (95% CI, 0.76, 1.54) and 0.76 (95% CI, 0.48, 1.23) per investigator and central assessment. PFS HR was 1.10 (90% CI, 0.92, 1.33) and 1.03 (90% CI, 0.83, 1.29) per investigator and central assessment. Conclusions: These results further confirm the similarity of ABP 215 and RP and support extrapolation to all available bevacizumab indications. Clinical trial information: NCT01966003.