Data presented at the 2017 American Society of Clinical Oncology Annual Meeting (ASCO; 2–6 June, IN, USA) has shown similarity in efficacy and safety between biosimilar trastuzumab candidate (CT-P6) and reference trastuzumab, in patients with early breast cancer and HER2 overexpression.
CT-P6 is the second of Celltrion’s (Yeonsu-gu, South Korea) oncological biosimilar product to be submitted to the EMA for approval in all indications of the reference trastuzumab, including HER2+ breast cancer and HER2+ metastatic stomach cancer.
The Phase III, double-blind, randomized, parallel-group study (NCT02162667) investigated the efficacy and safety of CT-P6, a biosimilar candidate of Herceptin, as neoadjuvant and adjuvant treatment in patients with HER2+ early breast cancer. After surgery, patients received CT-P6 or the reference trastuzumab to complete treatment for 1 year.
The primary endpoint was pathological complete response rate at surgery, which was 46.8% for CT-P6 and 50.4% for trastuzumab. The 95% confidence intervals for the risk ratio estimate were within the equivalence margin in both the pre-protocol set and intent to treat analyses. Secondary endpoints (overall response rate, pharmacokinetics, pharmacodynamics and safety), were shown to be similar between CT-P6 and trastuzumab. The serum concentrations of trastuzumab were similar between both groups during the neoadjuvant period.
Further details about the study are soon to be published in The Lancet Oncology.
Sources: Stebbing J, Baranau YV, Baryash V et al. Double-blind, randomized phase III study to compare the efficacy and safety of CT-P6, trastuzumab biosimilar candidate versus trastuzumab as neoadjuvant treatment in HER2 positive early breast cancer (EBC). Poster (510) Presented at: American Society of Clinical Oncology Annual Meeting (ASCO) (IN, USA, 2–6 June 2017); www.businesswire.com/news/home/20170604005015/en/Biosimilar-trastuzumab-candidate-CT-P6-shown-similar-efficacy