Tucatinib

Products

Tucatinib was approved in the United States and many countries in 2020 in film-coated tablet form (Tukysa).

Structure and properties

Tucatinib (C₂₆H₂₄N₈O₂, M_r = 480.5 g/mol)

Effects

Tucatinib has antitumor and antiproliferative properties. The effects are due to inhibition of HER2 tyrosine kinase. The half-life is approximately 8.5 hours.

Indications

In combination with trastuzumab and capecitabine for the treatment of patients with metastatic HER2-positive breast cancer who have previously received two or more anti-HER2 therapy regimens in any setting, including trastuzumab, pertuzumab, and trastuzumab emtansine (T-DM1).

Dosing

According to the SmPC. Tablets are taken in the morning and evening 12 hours apart, independent of meals.

Contraindications

• Hypersensitivity

For complete precautions, see the drug label.

Interactions

Tucatinib is metabolized predominantly by CYP2C8 and to a lesser extent by CYP3A. It is transported by P-glycoprotein and BCRP.

Adverse effects

The most common possible adverse effects include:

• Nausea, vomiting, decreased appetite, diarrhea, stomatitis, abdominal pain.
• Palmar-plantar erythrodysesthesia.
• Fatigue
• Liver toxicity
• Headache
• Anemia
• Rash