What diseases is tucatinib used to treat? How effective is it?

Tucatinib, trade name: Tukysa, is an oral tyrosine kinase inhibitor (TKI ), mainly used to treat HER2-positive (human epidermal growth factor receptor 2-positive) advanced or metastatic tumors.

Tucatinib in combination with trastuzumab and capecitabine for the treatment of adult patients with advanced unresectable or metastaticHER2 positive breast cancer, including those with brain metastases. These patients had previously received one or more antiHER2-based treatment regimens in the metastatic setting. Tucatinib can penetrate the blood-brain barrier and also has a good effect on breast cancer that has metastasized to the brain. By targeting the HER2 receptor, tucatinib can inhibit the proliferation of tumor cells, promote cell apoptosis, and reduce the blood supply of tumors, thereby prolonging patients' survival and improving their quality of life.

Tucatinib in combination with trastuzumab is indicated for the treatment of adult patients with RASwild-type, HER2positive unresectable or metastatic colorectal cancer. These patients progressed after receiving fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy.

The addition of tucatinib provides a new treatment option for these patients who have poor response to chemotherapy.

Tucatinib performed well in clinical trials. In the HER2CLIMB trial, the treatment regimen of tucatinib combined with trastuzumab and capecitabine significantly prolonged the progression-free survival (PFS) and overall survival (OS) of patients. Especially for those patients with brain metastases, the addition of tucatinib significantly reduced the risk of disease progression or death.

Study data showed that the combination of tucatinib reduced the risk of death by 34% compared with trastuzumab and capecitabine alone. In addition, the addition of tucatinib also significantly improved the intracranial disease control rate in patients with brain metastases.

Tucatinib was relatively well tolerated, allowing patients to undergo long-term treatment. Common side effects include diarrhea, palmoplantar erythema syndrome (PPE), nausea, fatigue, liver toxicity, vomiting, stomatitis, decreased appetite, abdominal pain, headache, anemia and rash, but these side effects are usually mild and controllable.

In the MOUNTAINEER clinical trial, the combination of tucatinib and trastuzumab in HER2positive metastatic colorectal cancer demonstrated an overall response rate of 38%. The median overall survival of patients who received tucatinib combination therapy reached 24.1 months, which exceeded 2 years, providing patients with a significant survival benefit.

The addition of tucatinib provides these patients with poor response to chemotherapy with a new treatment option and significantly improves their quality of life.

Compared with traditional chemotherapy methods and other anti-HER2 drugs, tucatinib is a highly selective HER2 tyrosine kinase inhibitor that can precisely act on HER2-positive tumor cells and minimize the impact on healthy cells.

This allows tucatinib to prolong patient survival while maintaining a relatively good quality of life.

Tucatinib can penetrate the blood-brain barrier and has good efficacy in patients with breast cancer and colorectal cancer that have metastasized to the brain.

This provides new treatment hope for patients with brain metastases.

Common side effects of tucatinib include diarrhea, nausea, fatigue, etc., but these side effects are usually mild and controllable.

Compared with other antiHER2 drugs, tucatinib is less toxic to the gastrointestinal tract and skin, allowing patients to better tolerate the treatment.

References:

https://aacrjournals.org/cancerdiscovery/article/10/8/1090/2631/Tucatinib-Is-Active-Against-Brain-Metastases-in