Adam M. Brufsky, MD, PhD
In December 2017, the FDA approved the trastuzumab (Herceptin) biosimilar MYL-1401O (Ogivri; trastuzumab-dkst) for patients with HER2-positive breast cancer, as well as metastatic gastric or gastroesophageal junction adenocarcinoma.
However, the adoption of biosimilars has been slow for some physicians, as there has not been a compelling enough reason to choose them over the originator drug, says Adam Brufsky, MD, PhD. If payers can demonstrate that using a biosimilar will result in a significant reduction in cost, then biosimilars may become more appealing, he adds.
The biologics license application for MYL-1401O, submitted in November 2016, cited phase III results from the HERiTAge study. This was a 2-part, multicenter, double-blind, randomized, parallel-group study of patients with measurable HER2-positive metastatic breast cancer who had not received prior chemotherapy or trastuzumab. MYL-1401O demonstrated an overall response rate (ORR) of 69.6% after 24 weeks among women who received MYL-1401O in combination with a taxane compared with a 64% ORR for patients who took trastuzumab plus a taxane. Additionally, the progression-free survival (PFS) was similar in the 2 groups (stratified HR, 0.95; 95% CI, 0.71-1.25).
Codeveloped by Mylan and Biocon, MYL-1401O is approved for the same indications as trastuzumab; however, Genentech, the manufacturer of trastuzumab, holds an exclusive license at this time for the metastatic gastric cancer indication.
In an interview with OncLive,
Brufsky, professor of medicine, associate chief, Division of Hematology/Oncology, co-director, Comprehensive Breast Cancer Center, associate director, Clinical Investigation, University of Pittsburgh, commented on the FDA approval of MYL-1401O and discussed the adoption of biosimilars in oncology.
OncLive: Can you provide some background on the HERiTAge study?
The idea behind a biosimilar is that is it similar; it is not superior and it is not inferior. It is very important to understand that. That means, before a biosimilar even gets to a clinical trial, there has to be protein assays, protein electrophoreses, and glycosylation assays that show similarity to the originator compound. All of that has to be done before it gets to human beings. Once you get to human beings, within a confidence interval, it has to show that it is similar—it cannot be inferior or superior. In fact, one biosimilar did not get an approval because it was superior. It is very important to be within the confidence interval.