Key clinical point: In patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer, CT-P6, a trastuzumab biosimilar shows 3-year survival comparable with trastuzumab.
Major finding: Median disease-free survival (DFS), overall survival (OS), and progression-free survival (PFS) were not reached in either group. In the CT-P6 vs trastuzumab group, the 3-year DFS, PFS, and OS rates were 83% vs 83%, 81% vs 87%, and 93% vs 94%, respectively.
Study details: A randomized, double-blind, active-controlled, phase 3 equivalence trial of 549 patients with HER2 ‑positive early breast cancer who received neoadjuvant treatment with CT-P6 or trastuzumab with chemotherapy, followed by surgery. Patients were followed up for 3 years (n=528) after receiving adjuvant CT-P6 or trastuzumab.
Disclosures: The study was funded by Celltrion, Inc. The authors received grants and consulting/advisory fees from various sources. Dr. SJ Lee and Dr. S Kim were employees of and/or stockholders in Celltrion.
Source: Stebbing J et al. Breast Cancer Res Treat. 2021 Jun 20. doi: 10.1007/s10549-021-06240-5 .