Clinical Efficacy and Safety of the BAT1706 (proposed Bevacizumab Biosimilar) Compared with Reference Bevacizumab in Patients with Advanced Nonsquamous NSCLC: A Randomized, Double-Blind, Phase III Study.

9041 Background: A Randomized, Double-blind, Phase III Study was conducted to confirm clinical similarity between BAT1706, a proposed biosimilar to reference bevacizumab, and EU-bevacizumab in patients with advanced non-squamous non-small cell lung cancer (NSCLC). Methods: Patients were randomized 1:1 to BAT1706 plus paclitaxel and carboplatin (Arm A) or EU-bevacizumab plus paclitaxel and carboplatin (Arm B) given three weeks for 6 cycles, followed by maintenance therapy with BAT1706 or EU- bevacizumab. The primary endpoint was overall response rate at Week 18 (ORR18). Secondary endpoints included ORR at Week 6 and 12, best ORR, duration of response (DoR), progression-free survival (PFS), and overall survival (OS). Results: A total of 651 patients were randomized: BAT1706 (n = 325) or EU- bevacizumab (n = 326). In total, 649 randomized patients (BAT1706 (n = 325) or EU- bevacizumab (n = 324)) received at least one cycle of combination treatment. The median duration of therapy was 29.1 weeks (ranging from 3.0 to 62.1 weeks) in the Arm A and 27.0 weeks (ranging from 3.0 to 53.9 weeks) in the Arm B. The extent of exposure to BAT1706 and EU- bevacizumab was similar between these two arms. Overall, the proportion of patients achieving an ORR by Week 18 was comparable across Arm A and B (48.0% and 44.5%). The ORR risk ratio of 1.08 with 90% CI (0.94, 1.24) and the ORR risk difference of 0.03, with 95% CI (-0.04, 0.11) were within pre-specified equivalence margin. In addition, the multivariate-adjusted risk ratio was 1.07, with a 90% CI (0.93, 1.22). The ORR18 risk difference between BAT1706 and EU- bevacizumab was 0.03, with the 2-sided 95% CI (-0.04, 0.11) that fell entirely within pre-specified equivalence margin. In addition, the multivariate-adjusted risk difference was 0.03, with a 95% CI (-0.04, 0.11). The hazard ratio stratified for time to PFS was 0.915 and the PFS rate at 12 months was 20.7% versus 21.8%. At the end of the study, there were no significant differences between both the treatments. The incidence of treatment-emergent adverse events (TEAEs) and study drug-related TEAEs was similar between these two arms. Overall, the safety profiles of BAT1706 were consistent with that of EU- bevacizumab, no new safety signals or noticeable trends were observed. The mean serum concentrations were comparable between BAT1706 and EU- bevacizumab over the entire sampling interval both in pre-dose and post-dose. The incidence of positive anti-drug antibodies results was low (≤5%) and decreased over time in both treatment arms. No patient was detected to have positive neutralizing anti-drug antibody result during the study. Conclusions: BAT1706 demonstrated clinical equivalence to reference EU-bevacizumab in terms of efficacy, safety, pharmacokinetics, and immunogenicity. Clinical trial information: NCT03329911.