What should I do if I become resistant to tucatinib?

When a patient develops resistance to tucatinib (tucatinib), doctors will conduct a comprehensive examination and evaluation to confirm whether resistance indeed exists. Based on the evaluation results, your doctor may adjust your treatment plan. This may include switching to other targeted drugs or chemotherapy drugs to find new treatment strategies to inhibit tumor growth. In some cases, a combination of medications may also be considered to increase the effectiveness of treatment.

Tucatinib is an investigational oral tyrosine kinase inhibitor that is highly selective for the kinase domain of HER2 and has minimal inhibitory effects on the epidermal growth factor receptor, which may alter the toxicity profile. In a Phase 1 dose-escalation trial, tucatinib in combination with trastuzumab and capecitabine showed encouraging anti-tumor activity in patients with HER2-positive metastatic breast cancer, including those with brain metastases. The regimen was also associated with diarrhea, nausea, palmar-plantar dysesthesia syndrome, fatigue, and vomiting; however, no more than 10% of patients experienced grade 3 or higher treatment-related toxicities.

It is understood that the original drug Tucatinib has not yet been launched in China, so it has not entered the scope of domestic medical insurance. Patients in need cannot yet purchase this drug in pharmacies or hospitals. The price of the European version of tucatinib original drug sold overseas is around RMB 72,000 (the price may fluctuate due to exchange rates), which is expensive. There are also generic drugs of tucatinib produced in other countries. The price of Tucatinib produced by a Lao pharmaceutical factory is around 6,400 yuan (the price may fluctuate due to the exchange rate). The price is much cheaper than the original drug, and the ingredients of foreign generic drugs are basically the same as the original drug.