Efficacy and safety of IBI305 compared with bevacizumab in advanced non-squamous NSCLC patients as first-line treatment in a randomized, double-blind, phase III study.

9095 Background: IBI305 is a recombinant humanized anti-VEGF monoclonal antibody, a biosimilar candidate to bevacizumab in analytical and functional comparisons. Pharmacokinetic similarity has been demonstrated in healthy males. Here we present primary efficacy and safety results from a phase 3 comparative study in non-small cell lung cancer (NSCLC). Methods: In this double-blind, active-controlled study, subjects with advanced non-squamous NSCLC on first-line treatment with carboplatin and paclitaxel were randomized (1:1) to IBI305 or bevacizumab (15 mg/kg IV Q3W). After six cycles, patients were on maintenance treatment with IBI305 or bevacizumab (7.5 mg/kg IV Q3W) till progression. Clinical equivalence of the primary endpoint, confirmed objective response rate (ORR) was evaluated by comparing the 2-sided 90% confidence interval (CI) of the risk ratio (RR) between study arms with the prespecified margin (0.75, 1.33). Results: A total of 450 subjects were randomized (IBI305: n = 224; bevacizumab: n = 226). Baseline characteristics were well balanced between treatment arms. ORR evaluated by Independent Radiological Review Committee (IRRC) in full analysis set (FAS) was 44.3% (98/221) for IBI305 and 46.4% (102/220) for bevacizumab; the RR for ORR was 0.95 (90% CI: 0.803, 1.135). Sensitive analysis result on RRs of ORR in Intention to Treat (ITT) population (IBI305: n = 224; bevacizumab: n = 226) and other analysis set were consistent and all within the prespecified equivalence margin. The medium PFS were 8.4 months for IBI305 and 8.3 months for bevacizumab and duration of response (DOR) was also similar in both arms. Treatment-emergent adverse events (TEAEs) were well balanced between treatment arms and consistent with the known adverse event profile of bevacizumab. Patients developing binding antibodies were 0.5% in the IBI305 arm vs 0% in the bevacizumab arm; no subject tested positive for neutralizing antibodies. Conclusions: This is the first released phase 3 clinical study with maintenance treatment for bevacizumab biosimilar in NSCLC patients till now. The comparative study met its predefined primary endpoint that the RR for confirmed ORR was within the prespecified equivalence margin. There was no significant difference between the two arms in safety profile and immunogenicity. Clinical trial information: NCT02954172.