FDA approves tucatinib combination for HER2-positive breast cancer

The FDA has approved tucatinib (Tukysa) in combination with trastuzumab (Herceptin) and pertuzumab (Perjeta) as a maintenance therapy for adults with unresectable locally advanced or metastatic HER2-positive breast cancer. This treatment is administered following induction therapy to help prevent cancer progression.

The approval is supported by data from the phase 3 HER2CLIMB-05 trial involving 654 adults. The study found that patients receiving the tucatinib triplet achieved a median progression-free survival of 24.9 months, compared to 16.3 months for those in the placebo arm. This represents a 36% reduction in the risk of cancer progression or death. While progression-free survival data was significant, overall survival data was not yet mature at the time of analysis.

The prescribed regimen involves 300 mg of tucatinib taken orally twice daily, alongside trastuzumab and pertuzumab, until the disease progresses or unacceptable toxicity occurs. The FDA-mandated prescribing information includes a boxed warning for hepatotoxicity, as well as precautions regarding diarrhea, embryo-fetal toxicity, and increased serum creatinine.