The biosimilar ABP 980 may not be inferior to trastuzumab for treatment of patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer, according to results announced by Amgen and Allergan.1

ABP 980 may not, however, be superior for achieving pathologic complete response in these patients.

In a randomized, multicenter, double-blinded phase 3 study, which evaluated the efficacy and safety of ABP 980 compared to trastuzumab, researchers observed 725 adult female patients with HER2+ breast cancer.

Upon completion of run-in chemotherapy that consisted of epirubicin and cyclophosphamide every 3 weeks for 4 cycles in the neoadjuvant phase, 364 patients received ABP 980, while 361 received trastuzumab along with paclitaxel.

Surgery was completed 3 to 7 weeks after the last dose of treatment in the neoadjuvant phase; pathologic response was then analyzed.

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It was found that the primary endpoint had a prespecified equivalence margin of +/- 13%; the observed upper end of the confidence interval was 13.4%.

Adverse events were comparable between ABP 980 and trastuzumab in the adjuvant phase of the study. While there were more serious adverse events found to be reported in the ABP 980 group in the neoadjuvant phase of the study, it was found that the majority of these events were not likely to be related to the investigational product.

Reference

  1. Amgen and allergan announce top-line results from phase 3 study evaluating ABP 980 compared with trastuzumab in patients with human epidermal growth factor receptor 2-positive early breast cancer. PRNewswire. http://www.prnewswire.com/news-releases/amgen-and-allergan-announce-top-line-results-from-phase-3-study-evaluating-abp-980-compared-with-trastuzumab-in-patients-with-human-epidermal-growth-factor-receptor-2-positive-early-breast-cancer-300301923.html. Updated July 21, 2016. Accessed: July 25, 2016.