The FDA approved trastuzumab-dkst (Ogivri, Mylan-Biocon) as a biosimilar to trastuzumab (Herceptin, Genentech) for the treatment of patients with breast or metastatic breast, gastric or gastroesophageal junction adenocarcinoma whose tumors overexpress the HER2 gene. 

Trastuzumab-dkst is the first biosimilar approved in the United States for the treatment of breast cancer or stomach cancer, and the second biosimilar approved for the treatment of cancer. Ogivri has been approved as a biosimilar, not an interchangeable product.

The approval for trastuzumab-dkst is based on a review of evidence that included extensive structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamic data, clinical immunogenicity data, and other clinical safety and effectiveness data that demonstrated trastuzumab-dkst was biosimilar to trastuzumab. The data showed that trastuzumab-dkst is highly similar to trastuzumab and that no clinically meaningful differences exist between the biosimilar product and trastuzumab in terms of safety, purity and potency. The FDA’s decision follows the unanimous vote by the agency’s Oncologic Drugs Advisory Committee in July 2017, recommending approval for trastuzumab-dkst.

Common side effects of trastuzumab-dkst for the treatment of HER2-positive breast cancer include headache, diarrhea, nausea, chills, fever, infection, congestive heart failure, insomnia, cough and rash. Common side effects of trastuzumab-dkst for the treatment of HER2-positive metastatic stomach cancer include low neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis and dysgeusia. Serious side effects of trastuzumab-dkst include worsening of chemotherapy-induced neutropenia.

Like trastuzumab, the labeling for trastuzumab-dkst contains a boxed warning to alert health care professionals and patients about increased risks for cardiomyopathy, infusion reactions, pulmonary toxicity and embryofetal toxicity. Patients should be told to stop taking trastuzumab-dkst if cardiomyopathy, anaphylaxis, angioedema, interstitial pneumonitis or acute respiratory distress syndrome occur. Patients should be advised of the biosimilar’s potential risk to a developing fetus and to use effective contraception. Click here for prescribing information.

Biological products are generally derived from a living organism and can come from many sources, such as humans, animals, microorganisms or yeast, according to the FDA. A biosimilar is a biological product that is approved based on data showing that it is highly similar to a biological product already approved by the FDA (reference product) and has no clinically meaningful differences in terms of safety, purity and potency (i.e., safety and effectiveness) from the reference product, in addition to meeting other criteria specified by law.

Mylan and Biocon’s biosimilar of trastuzumab also is under review by regulatory authorities in Australia, Canada, Europe and several other markets. It is already approved in 19 countries, including India.

—Marie Rosenthal