Dr. Hope Rugo on Safety of Trastuzumab Biosimilar for HER2+ Breast Cancer

Hope Rugo, MD, a professor of Medicine and director of the Breast Oncology Clinical Trials Program at the UCSF Helen Diller Family Comprehensive Cancer Center, discusses MYL-1401O, a proposed biosimilar for trastuzumab (Herceptin), in patients with HER2-positive metastatic breast cancer.

While there were not enough patients in the trial to document safety without a shadow of a doubt, the biosimilar was shown to be very safe, says Hugo. The only toxicities that occurred were related to the chemotherapy andthere were none that could be directly attributed to the antibody. Population pharmacogenetics were also similar. The immunogenicity, or the ability to make anti-drug antibody, was about 2.5% in both arms, which is similar to what has been reported for Herceptin in the past, says Rugo.

Overall the study demonstrated that this proposed trastuzumab biosimilar is really similar and fits the regulatory guidelines. For that reason, Rugo is hopeful that the submission to the regulatory agencies will be successful. In the United States, however the biosimilar will not be used for a while because there is still patent life for Herceptin.