A Randomized, Double-Blind, Phase III Study in India for Comparing Efficacy, Safety, and PK of ZRC-3277 (Pertuzumab Biosimilar) With Perjeta® in Patients With HER2-Positive Metastatic Breast Cancer

Abstract

Introduction: To evaluate the efficacy, safety, pharmacokinetics (PK), and immunogenicity of ZRC-3277 (pertuzumab biosimilar) with Perjeta® (pertuzumab) in previously untreated patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC).

Patients and methods: This phase III, multicenter, double-blind study across 38 sites in India randomized (1:1) patients with HER2-positive MBC in either the ZRC-3277 or Perjeta® group. Both groups also received trastuzumab and docetaxel. Of 268 enrolled patients, mITT population had 243 patients (119 and 124 in the ZRC-3277 and Perjeta® groups, respectively). The primary objective was to compare the between-group objective response rate (ORR) after 6 cycles of treatment. ORR was determined by evaluating scans of computed tomography or magnetic resonance imaging following Response Evaluation Criteria in Solid Tumor (RECIST 1.1). Two-sided 95% confidence interval (95% CI) for the difference in ORR was determined to evaluate the noninferiority of ZRC-3277 to Perjeta®. The secondary outcomes included the assessment of PK, immunogenicity, and safety between the 2 groups.

Results: In the mITT population, 104 (87.39%) and 114 (91.94%) participants achieved the ORR in the ZRC-3277 and Perjeta® groups, respectively. For predefined -15% noninferiority margin, obtained 2-sided 95% CIs (-12.19%, 3.11%) for the difference in ORR (-4.55%) between the 2 groups demonstrated the noninferiority of ZRC-3277 to Perjeta®. PK, immunogenicity, and safety were not significantly different between the 2 groups.

Conclusion: Efficacy, PK, immunogenicity, and safety profiles of ZRC-3277 was found to be similar to those of Perjeta®.

Keywords: Clinical care; Drug accessibility; Drug affordability; Immunogenicity; Non-inferiority.