First Biosimilar Approved for Breast, Stomach Cancers

Today, the FDA approved trastuzumab-dkst (Ogivri) for breast cancer or metastatic gastric or gastroesophageal junction adenocarcinoma in patients whose tumors are HER2+, according to a press release.

The trastuzumab (Herceptin) biosimilar is the first to be approved for breast or stomach cancer, according to the FDA. Trastuzumab-dkst is also the second biosimilar approved for cancer.

The FDA advises health care professionals to review the prescribing information before starting patients on the biosimilar.

“The FDA continues to grow the number of biosimilar approvals, helping to promote competition that can lower health care costs. This is especially important when it comes to diseases like cancer, that have a high cost burden for patients,” said FDA Commissioner Scott Gottlieb, MD. “We’re committed to taking new policy steps to advance our biosimilar pathway and promote more competition for biological drugs.”

The new approval of trastuzumab-dkst was based on structural and functional characterization, animal studies, human pharmacokinetic and pharmacodynamics studies, clinical immunogenicity data, and other safety and efficacy data, according to the release. The analysis of these data showed that trastuzumab-dkst is a biosimilar to reference trastuzumab.

However, the FDA has not approved trastuzumab-dkst as an interchangeable drug.

For patients with HER2+ breast cancer, common adverse effects of the biosimilar include headache, diarrhea, nausea, chills, fever, infection, congestive heart failure, insomnia, cough, and rash. For patients with HER2+ metastatic stomach cancer, adverse effects include neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia, according to the release.

The FDA warns that serious side effects of trastuzumab-dkst include worsening of chemotherapy-induced neutropenia.

For both the biosimilar and the reference product, there is a Boxed Warning that alerts providers and patients to the potential for increased risks of cardiomyopathy, infusion reactions, pulmonary toxicity, and embryo-fetal toxicity.

The FDA cautions that patients should stop treatment with trastuzumab-dkst if they experience cardiomyopathy, anaphylaxis, angioedema, interstitial pneumonitis, or acute respiratory distress syndrome.

Providers should also educate patients about the potential risk trastuzumab-dkst poses to developing fetuses and the importance of contraceptive use while taking the cancer drug, according to the release.