Tucatinib (Tukysa) — HER2-Positive Breast Cancer | GLT

Generic Info

Tucatinib, marketed under the brand name Tukysa, is an oral tyrosine kinase inhibitor (TKI) that selectively targets the human epidermal growth factor receptor 2 (HER2). It is developed by Seagen Inc. (now part of Pfizer). The U.S. FDA approved Tukysa in April 2020 for adults with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, in combination with trastuzumab and capecitabine. It is supplied as 50 mg and 150 mg film-coated tablets for oral use.

What Is Tucatinib Used For?

Tucatinib is used to treat adults with HER2-positive metastatic breast cancer that has spread to other parts of the body (including the brain) or cannot be removed by surgery, after at least one prior anti-HER2-based treatment. In 2023, the indication was expanded to include RAS wild-type, HER2-positive metastatic colorectal cancer in combination with trastuzumab. Tucatinib is always given together with other anti-HER2 medicines, never as a monotherapy.

How Does Tucatinib Work?

In HER2-positive cancers, the HER2 protein is overexpressed and acts as a growth signal, driving uncontrolled tumor cell division. Tucatinib is a highly selective HER2 kinase inhibitor: it binds the HER2 receptor and blocks phosphorylation of HER2 and HER3, which shuts down the downstream MAPK and AKT signaling pathways and inhibits tumor cell proliferation. Unlike antibody-based HER2 therapies, tucatinib is a small molecule that crosses the blood-brain barrier, making it effective against brain metastases — a key advantage for patients with central nervous system involvement.

Indications

• HER2-positive advanced unresectable or metastatic breast cancer (in combination with trastuzumab and capecitabine)
• HER2-positive metastatic breast cancer with brain metastases
• RAS wild-type, HER2-positive metastatic colorectal cancer (in combination with trastuzumab)

Dosage

The recommended dose of tucatinib is 300 mg orally twice daily (600 mg total per day), taken in combination with trastuzumab and capecitabine, until disease progression or unacceptable toxicity. Tablets should be taken with or without food, approximately 12 hours apart, and swallowed whole. Dose reductions or interruptions may be required for adverse reactions. Tucatinib is available in 50 mg and 150 mg tablet strengths.

Side Effects

The most common side effects of tucatinib in combination with trastuzumab and capecitabine include:

• Diarrhea (can be severe — may require dose modification)
• Palmar-plantar erythrodysesthesia (hand-foot syndrome)
• Nausea and vomiting
• Stomatitis (mouth sores)
• Fatigue
• Decreased appetite
• Anemia and elevated liver function tests

Serious side effects include severe diarrhea (with risk of dehydration and kidney problems) and hepatotoxicity. Liver function should be monitored before starting treatment and every 3 weeks during therapy.

Storage

Store tucatinib tablets at room temperature (20°C to 25°C / 68°F to 77°F). Keep in the original container, tightly closed, and out of reach of children. Do not use after the expiration date printed on the package.

Why Choose the GLT?

GIVE LIFE TIME LIMITED (GLT) sources genuine, manufacturer-sealed Tukysa (tucatinib) tablets and ships internationally with reliable logistics. We support both institutional buyers (hospitals, pharmacies, distributors) and individual patients, with responsive customer service and clear ordering guidance throughout the process.

How to Order

Contact our team via WhatsApp or email to confirm current availability, pricing, and shipping options for your region. Provide the required strength and quantity, and we will guide you through the ordering and delivery process.

FAQ

Q: Is Tukysa a chemotherapy?
No. Tucatinib is a targeted therapy (a tyrosine kinase inhibitor) that blocks the HER2 growth signal, not a conventional chemotherapy.

Q: Can Tukysa treat brain metastases?
Yes. Tucatinib crosses the blood-brain barrier and has demonstrated activity against HER2-positive brain metastases, an important advantage over antibody-based HER2 therapies.

Q: How is Tukysa taken?
It is taken orally, 300 mg twice daily, together with trastuzumab and capecitabine.