- The US Food and Drug Administration (FDA) has approved tucatinib for the treatment of HER2-positive metastatic breast cancer.
- The recommended dose is 300 mg taken orally twice daily with or without food.
Why this matters
- Tucatinib is the first new drug approved under Project Orbis, an international collaboration.
- The approval was based on the phase 3 HER2CLIMB trial.
- Previously treated patients with HER2-positive metastatic breast cancer (n=612) were randomly assigned to either tucatinib or placebo in combination with trastuzumab and capecitabine.
- Median PFS was 7.8 months in the tucatinib group vs 5.6 months in the placebo group.
- PFS outcomes in the brain metastases subgroup followed a similar pattern.
- Median OS was 21.9 months in the tucatinib group vs 17.4 months in the placebo group.
- The most common adverse events associated with tucatinib were diarrhea, palmar-plantar erythrodysesthesia syndrome, nausea, fatigue, hepatotoxicity, vomiting, stomatitis, decreased appetite, abdominal pain, headache, anemia, and rash.
- Tucatinib can cause diarrhea associated with dehydration, acute kidney injury, and death.
- Tucatinib can also cause severe hepatotoxicity; liver function tests are warranted.
For Prescribing Information, click here.