Tucatinib

Generic Details

Generic Name

Tucatinib

Other Names

  • ONT-380

Drug Class

  • Kinase inhibitor

Chemical Formula

C26H24ClFN4O4S

Molecular Weight

532.01 g/mol

Mechanism of Action

  • Tucatinib is a tyrosine kinase inhibitor that selectively targets HER2 (human epidermal growth factor receptor 2)

Indications

  • Tucatinib is indicated in combination with trastuzumab and capecitabine for the treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting.

Common Dosage Forms

  • Tablet - 300mg

Typical Dosage

  • 300mg orally twice daily with food until disease progression or unacceptable toxicity

Pediatric Dosage

  • Safety and efficacy have not been established in pediatric patients

Geriatric Dosage

  • No dosage adjustment is necessary based on age

Side Effects

  • Common side effects may include diarrhea, palmar-plantar erythrodysesthesia, nausea, fatigue, vomiting, and decreased appetite.

Contraindications

  • Hypersensitivity to tucatinib or any component of the formulation

Pregnancy Category

  • N/A - not recommended during pregnancy

Lactation Safety

  • Unknown if excreted in human milk; discontinue breastfeeding during treatment and for 1 week after the last dose

Drug Interactions

  • Avoid concurrent use with strong CYP3A4 inhibitors or inducers

Overdose Symptoms

  • Limited information available; manage overdose with supportive care

Antidote for Overdose

  • N/A

Storage Conditions

  • Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F)

Pharmacokinetics

  • Absorption: Tucatinib reaches peak plasma concentration in 2 to 4 hours
  • Distribution: Highly bound to plasma proteins (over 99%)
  • Metabolism: Metabolized primarily by CYP3A4
  • Excretion: Eliminated in feces (76%) and urine (19%)

Precautions

  • Monitor closely for diarrhea and hepatotoxicity; may require dose modifications or interruptions

Warnings

  • Hepatotoxicity, diarrhea, and interstitial lung disease/pneumonitis are the most common serious adverse reactions

Others

  • Consider dose reduction for severe diarrhea or elevated liver enzymes to manage adverse reactions