HD201 Comparable to Referent Trastuzumab for HER2-Positive Breast Cancer

According to results from a multicenter phase 3 randomized clinical trial, potential trastuzumab biosimilar HD201 and referent trastuzumab had comparable efficacy in the neoadjuvant treatment of patients with HER2-positive breast cancer.

"The high cost of referent trastuzumab therapy is a burden for health care systems, and in many countries, patients have only limited access because of the high costs,” explained Xavier Pivot, MD, PhD, Institute of Cancer Strasbourg, France, and colleagues, adding, “the need for less expensive alternatives to referent trastuzumab can potentially be met by introducing new biosimilars."

The TROIKA trial enrolled 300 patients with HER2-positive breast cancer. Patients were randomly assigned to receive either HD201 or referent trastuzumab in combination with standard chemotherapy for a duration of 12 weeks. The primary endpoints of the trial were total pathological complete response (tpCR) and progression-free survival (PFS).

The trial results demonstrated no statistically significant difference in efficacy between HD201 and referent trastuzumab. The tpCR rate in the HD201 group was 45% vs 48.7% in the referent trastuzumab group. The ratio of the tpCR rates between the HD201 and referent trastuzumab arms was 0.92. At the 2-year follow-up, the PFS rate was 85% in the HD201 group and 83% in the referent trastuzumab group. Overall survival rates were similar between the 2 treatment groups.

Both HD201 and referent trastuzumab exhibited a manageable safety profile, with no significant differences observed in treatment-related adverse events. Fatigue, nausea, and neutropenia were among the most reported adverse events, and their incidence and severity were comparable in both treatment groups.

Serious treatment-related adverse events occurred in 24 (9.6%) and 17 (6.7%) participants in the HD201 and referent trastuzumab treatment arms, respectively. There were 16 participants (6.4%) in the HD201 group and 12 (4.8%) in the referent trastuzumab group who discontinued treatment due to treatment-related adverse events.

“These results support the application submitted for registration of HD201 as a biosimilar of trastuzumab,” concluded Dr Pivot, et al.

Source:

Pivot X, Georgievich MA, Shamrai V, et al. Efficacy of HD201 vs referent trastuzumab in patients with ERBB2-positive breast cancer treated in the neoadjuvant setting: a multicenter phase 3 randomized clinical trial [published correction appears in JAMA Oncol. 2022 May 1;8(5):784]. JAMA Oncol. 2022;8(5):698-705. DOI: 10.1001/jamaoncol.2021.8171