Tucatinib/Tucatinib: Leading a new generation of targeted therapy for HER2-positive breast cancer

Tucatinib/Tucatinib has successfully become a third-generation targeted treatment drug for HER2-positive breast cancer due to its excellent therapeutic effect and innovative mechanism. With the continuous advancement of targeted therapy technology, the treatment of HER2-positive breast cancer has undergone earth-shaking changes. From early dual blockade with the monoclonal antibodies trastuzumab and pertuzumab, to first-line taxane chemotherapy, to second-line treatment with the antibody drug conjugate T-DM1, each step marked a medical breakthrough.

However, for patients with advanced stageHER2-positive breast cancer, third-line and above treatment options have always been a problem, and the results are often unsatisfactory and accompanied by greater toxicity. Tucatinib stands out for its highly selective and ATP-competitive small molecule TKI properties. It is extremely potent at the HER2 receptor and works at the nanomolar level. Cell experiments have proven that tucatinib is 1,000 times more specific for HER2 than EGFR, demonstrating its excellent targeting ability. As a third-generation HER2 tyrosine kinase inhibitor (TKI), tucatinib not only inherits the efficacy of the second-generation drug neratinib, but also makes significant progress in toxicity control. When used in combination with capecitabine and trastuzumab, it is expected to become a new treatment benchmark after T-DM1.

In in vitro models, tucatinib strongly blocks the phosphorylation of HER2 and its downstream effector AKT3 in cell lines overexpressing HER2, thereby effectively inhibiting the proliferation of cancer cells. Even in EGFR-amplified cell lines, it exerts some inhibitory effects on phosphorylation and proliferation. What is more worth mentioning is that tucatinib can also basically inhibit the truncated form of HER2 for the p95/p110 mutation that causes trastuzumab resistance.

To sum up, tucatinib/tucatinib, as a third-generation targeted drug, has demonstrated excellent efficacy and innovative mechanism in the treatment of HER2-positive breast cancer, bringing new hope to patients.