Bevacizumab biosimilar and reference bevacizumab in subjects with stage IIIB/IV no squamous non-small cell lung cancer (NSCLC) (STELLA study): Results for the primary endpoint in a confirmatory, double-blind, randomized, controlled study.

Abstract

e21542 Background: MB02 is a proposed biosimilar of the reference bevacizumab. A multinational, double-blind, randomized, parallel group clinical study (STELLA) is undergoing to confirm clinical similarity between MB02 and bevacizumab in patients with stage IIIB/IV no squamous NSCLC. Methods: Subjects were randomized 1:1 to MB02 or bevacizumab (15 mg/kg) plus chemotherapy (paclitaxel [P] 200 mg/m2 and carboplatin [C] AUC6) on Day 1 of every 3-week cycle for 6 cycles (Week 18) followed by MB02/bevacizumab in blinded monotherapy until disease progression, treatment intolerance, death, patient withdrawal or end of study (Week 52). As primary study endpoint, the efficacy by means of the objective response rate (ORR) evaluated by an independent radiological committee (IRC) was compared between arms at Week 18. Secondary endpoints were Progression Free Survival (PFS) and Overall Survival (OS), safety and immunogenicity (assessed at 18 and 52 weeks). Results: 627 patients were randomized: MB02 (n = 315) and bevacizumab (n = 312). Demographic and baseline characteristics were well balanced between arms. The ORR results were comparable for subjects receiving MB02 or bevacizumab plus P/C. A Risk Ratio (RR) of 1.013 (90% CI: -0.037% to 0.059) and a Risk Difference (RD) of 0.011 (90% CI: -0.037% to 0.059), were within the similarity margin predefined by FDA (0.73, 1.36) and EMA (-12%, +12%) respectively. This ORR assessed by IRC was consistent with the investigator assessment criteria. There was no significant difference between arms for secondary efficacy endpoints (PFS/OS) at week 18. Up to primary endpoint cut-off point, the safety assessment showed no significant differences between MB02 and bevacizumab arms (including the immunogenicity assessment) in terms of nature, frequency and severity of the adverse events (AE), being anaemia and hypertension the most common IMP-related AEs, with a RD between treatment groups < 5%. New signals or observable trends were no reported for MB02-treated subjects. Additional information on the secondary endpoints will be available at week 52 (end of monotherapy period). Conclusions: The statistical analysis executed for ORRs confirm the equivalence of MB02 and bevacizumab, supporting the clinical activity of MB02 treatment. MB02 was well tolerated with manageable AEs in patients with Stage IIIB/IV NSCLC. Clinical trial information: NCT03296163.