Background: PF-06439535 is a bevacizumab biosimilar. We aimed to compare the efficacy and safety of PF-06439535 with that of reference bevacizumab (Avastin®) sourced from the EU (bevacizumab-EU), each with paclitaxel and carboplatin, in the first-line treatment of advanced non-squamous non-small-cell lung cancer (NSCLC).
Methods: In this double-blind, parallel-group study, we recruited patients from 159 centers in 27 countries. Participants were randomized 1:1 to receive PF-06439535 plus paclitaxel and carboplatin or bevacizumab-EU plus paclitaxel and carboplatin on day 1 of each 21-day cycle for 4-6 cycles, followed by blinded monotherapy with PF-06439535 or bevacizumab-EU until disease progression, unacceptable toxicity, withdrawal of consent, or the end of the study. Randomization was stratified by region, sex, and smoking history. The primary endpoint was objective response rate (ORR) in accordance with RECIST 1.1, based on responses achieved by week 19 and confirmed by week 25.
Results: Between 21 May 2015 and 14 November 2016, 719 patients were randomized to the PF-06439535 group (n = 358) or the bevacizumab-EU group (n = 361). As of data cutoff for analysis of the primary endpoint (8 May 2017), 45.3% (95% confidence interval [CI] 40.01-50.57) of patients in the PF-06439535 group and 44.6% (95% CI 39.40-49.89) of patients in the bevacizumab-EU group achieved an objective response by week 19 that was confirmed by week 25. The unstratified ORR risk ratio was 1.015 (95% CI 0.863-1.193; 90% CI 0.886-1.163), and the unstratified ORR risk difference was 0.653% (95% CI - 6.608 to 7.908); all three CIs fell within pre-specified equivalence margins. Using final data after study completion (22 December 2017), no notable differences in progression-free survival or overall survival were observed between the groups. The most frequently reported grade 3 or higher treatment-emergent adverse events were hypertension, neutropenia, and anemia. There were no clinically meaningful differences in safety, pharmacokinetics, or immunogenicity across treatment groups.
Conclusion: Among patients with advanced non-squamous NSCLC, PF-06439535 demonstrated similarity to bevacizumab-EU in terms of efficacy. Safety profiles for the two treatments were comparable.
Trial registration: ClinicalTrials.gov, NCT02364999.