Tucanat 150mg Tablet contains tucatinib, a targeted anticancer medicine belonging to the tyrosine kinase inhibitor class. It is used in combination with trastuzumab and capecitabine to treat adults with HER2-positive locally advanced unresectable or metastatic breast cancer, including breast cancer that has spread to the brain.

Tucatinib selectively blocks HER2 signalling, a pathway that helps HER2-positive cancer cells grow and survive. Tucanat is an oral targeted therapy and should be used under the supervision of an oncologist.

Tucanat 150mg Tablet is used for:

• HER2-positive locally advanced unresectable or metastatic breast cancer: It is used in combination with trastuzumab and capecitabine after previous HER2-directed treatment.

• HER2-positive breast cancer with brain metastases: Tucatinib-containing treatment can be used when breast cancer has spread to the brain.

Tucanat is used as part of a combination treatment regimen and should not be used alone for these indications.

Tucanat 150mg Tablet contains tucatinib, a tyrosine kinase inhibitor that selectively targets the HER2 protein.

HER2 is a receptor involved in signals that promote cancer cell growth and survival. Tucatinib blocks HER2 signalling, which can slow the growth and spread of HER2-positive cancer cells.

Tucatinib can also reach the central nervous system and has demonstrated activity in patients with HER2-positive breast cancer that has spread to the brain. It is used together with trastuzumab and capecitabine as part of the recommended treatment regimen.

Tell your doctor about all prescription medicines, over-the-counter medicines, vitamins and herbal supplements you take.

• Strong CYP3A or CYP2C8 inducers: Medicines such as rifampicin can reduce tucatinib levels and may reduce its effectiveness. Concomitant use should generally be avoided.

• Strong CYP2C8 inhibitors: Medicines such as gemfibrozil can increase tucatinib levels and may increase the risk of side effects. Your doctor may avoid the combination or adjust the dose.

• CYP3A substrates: Tucatinib can increase the levels of some medicines metabolised by CYP3A and may increase their toxicity. Tell your doctor if you take medicines with a narrow therapeutic range.

• P-glycoprotein substrates: Tucatinib can increase the levels of certain P-gp substrate medicines, such as digoxin. Additional monitoring or dose adjustment may be required.

• Store Tucanat 150mg Tablet below 30°C.

• Keep the tablets in their original packaging and protect them from moisture.

• Keep the medicine out of the reach of children.

• Do not use the tablets after the expiry date printed on the packaging.

Take Tucanat 150mg Tablet exactly as prescribed by your oncologist.

The usual recommended dose of tucatinib is 300mg twice daily, equivalent to two 150mg tablets twice a day. It is taken approximately 12 hours apart and may be taken with or without food.

Swallow the tablets whole with water. Do not crush, chew or break them.

Tucatinib is given together with trastuzumab and capecitabine. Follow the dosing schedule provided by your oncologist for all three medicines.

If you vomit after taking a dose, do not take another dose to replace it. Take the next dose at the usual scheduled time.

If you miss a dose, take it when you remember if it is less than 6 hours late. If it has been more than 6 hours, skip the missed dose and take the next dose at the usual time. Do not take two doses at the same time.

Do not change the dose or stop treatment without medical advice.

Common side effects may include:

• Diarrhoea

• Nausea

• Vomiting

• Mouth sores or stomatitis

• Rash

• Joint pain

• Fatigue

• Decreased appetite

• Weight loss

• Nosebleeds

• Changes in liver enzymes or bilirubin

Some side effects can be caused by tucatinib or by the combination with trastuzumab and capecitabine.

Serious side effects

Contact your doctor promptly if you develop:

• Severe or persistent diarrhoea, particularly if accompanied by weakness, dizziness or reduced urination

• Liver problems, such as yellowing of the skin or eyes, dark urine, unusual tiredness or persistent nausea

• Severe or persistent vomiting

• Signs of a serious allergic reaction, such as swelling of the face or throat or difficulty breathing

Your doctor may temporarily stop treatment or reduce the dose if significant side effects occur.

• Tucanat should be taken exactly as prescribed by your oncologist and is normally used together with trastuzumab and capecitabine.

• Take the two daily doses approximately 12 hours apart and try to take them at the same times each day.

• Drink enough fluids if you develop diarrhoea and contact your doctor if it is severe or persistent.

• Do not take an extra dose if you vomit after taking Tucanat.

• Tell your doctor about every medicine, supplement and herbal product you use because tucatinib has clinically important medicine interactions.

• Your doctor will monitor liver function during treatment. Attend all scheduled blood tests.

• Tell your doctor promptly about yellowing of the skin or eyes, dark urine, severe diarrhoea or other concerning symptoms.

• Do not stop Tucanat, trastuzumab or capecitabine without discussing it with your oncology team.

• Tucatinib is prescription-only in India and should be used under the supervision of an oncologist.