Efficacy and Safety of Biosimilar SCT510 Compared with Bevacizumab for the First-Line Treatment of Advanced Non-Squamous Non-Small Cell Lung Cancer: A Randomized, Double-Blind, Phase III Study

Introduction SCT510 is a biosimilar to bevacizumab (Avastin) reference product (RP) that is approved for various metastatic cancers. In this study, we aimed to demonstrate the equivalence of SCT510 and bevacizumab in terms of efficacy, safety, immunogenicity and pharmacokinetics (PK) in patients with advanced non-squamous non-small cell lung cancer (NSCLC). Methods Patients with non-squamous NSCLC were randomized equally to the SCT510 group (comprising SCT510, paclitaxel, and carboplatin) and the bevacizumab group (comprising bevacizumab, paclitaxel, and carboplatin) for 4–6 cycles, followed by maintenance monotherapy with SCT510. The primary endpoint was the objective response rate (ORR) at week 12. Secondary endpoints included 18-week ORR, disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and 1-year survival rate, as well as assessments of safety, immunogenicity, and multi-dose PK analysis. Results Between March 29, 2019, and April 27, 2021, 989 patients were screened and 567 eligible patients were randomly assigned to the SCT510 group (285 patients) and the bevacizumab group (282 patients). The ORR at week 12 was 52.6% [95% confidence interval (CI) 46.66–58.55%] in the SCT510 group and 52.5% (95% CI 46.47–58.47%) in the bevacizumab group. The ORR at week 18 was 55.4% (95% CI 49.46–61.30%) for SCT510 and 55.7% (95% CI 49.68–61.62%) for bevacizumab. The ORR risk ratio (RR) at weeks 12 and 18 was 0.99 (90% CI 0.873–1.133) and 0.99 (90% CI 0.872–1.114), respectively, both within the pre-specified equivalence margin of 0.75–1.33. There were no differences between the two groups in relation to other secondary endpoints, specifically DCR, DOR, PFS, OS, and 1-year survival rate. The overall safety findings were similar between the two treatment groups, and both SCT510 and bevacizumab RP exhibited low immunogenicity. Conclusions SCT510 is similar to bevacizumab in clinical efficacy, safety, immunogenicity, and PK in patients with advanced non-squamous NSCLC. The totality of the evidence supports the clinical equivalence of SCT510 and bevacizumab. Trial Registration NCT03792074.