FDA Approves Tukysa to Treat Advanced or Metastatic HER2-Positive Breast Cancer

The Food and Drug Administration (FDA) approved the targeted drug Tukysa (tucatinib) in combination with other medications to treat adults with HER2-positive breast cancer that can’t be removed surgically, or has spread other parts of the body, and who have received one or more prior therapies for metastatic disease.

Tukysa inhibits the protein HER2, whose overexpression is a driver of this type of breast cancer. Under the approval, the drug will be given along with another HER2 inhibitor, Herceptin (trastuzumab), and the chemotherapy capecitabine. The Tukysa regimen is meant for use after patients have completed treatment with one or more therapies containing an anti-HER2 drug.

The approval was based on findings from a clinical trial that included 612 patients with advanced or metastatic HER2-positive breast cancer, including some whose disease had spread to the brain. Patients who took the Tukysa combination went a median 7.8 months before experiencing disease progression, compared with 5.6 months in patients in the two-drug group. In the Tukysa group, the median overall survival was 21.9 months compared with 17.4 months in the placebo/Herceptin/capecitabine group.

Common side effects associated with Tukysa were diarrhea, burning or tingling discomfort in the hands and feet, nausea, fatigue, liver damage, vomiting, inflammation of the mouth and lips, decreased appetite, abdominal pain, headache, anemia and rash. Tukysa can also cause serious side effects including severe diarrhea associated with dehydration, acute kidney injury and death.

The FDA nod was part of Project Orbis, which allows drug developers to seek approvals from the governments of multiple countries simultaneously. In this case, the FDA collaborated with drug authorities in Australia, Canada, Singapore and Switzerland. However, Tukysa was still under review in those countries as of April 17.

Tukysa was approved four months prior to the FDA’s goal date, according to Dr. Richard Pazdur, director of the agency’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in its Center for Drug Evaluation and Research. He said the early approval was an example of the FDA’s commitment to expediting oncology drug development despite challenges posed by the COVID-19 pandemic and showing how their work to approve cancer therapies was not being delayed.

Check back later for what you need to know about this approval.