Differences between tucatinib/tucatinib and trastuzumab in the treatment of HER2-positive breast cancer

Tucatinib/Tucatinib and trastuzumab (formerly known as 8201, now also known as Fam-trastuzumab deruxtecan-nxki) are two important therapeutic drugs for HER2-positive breast cancer, but their mechanisms of action and efficacy are different.

Tucatinib is an oral tyrosine kinase inhibitor that is mainly used in combination with trastuzumab and capecitabine to treat patients with advanced or metastatic breast cancerHER2-positive breast cancer, especially those who have developed brain metastases. In the clinical trial of HER2CLIMB, the tucatinib combination treatment regimen significantly improved the progression-free survival (PFS) and overall survival (OS) of patients, and reduced the risk of disease progression or death. It is worth mentioning that tucatinib can cross the blood-brain barrier and has a therapeutic effect on brain metastases, which brings new treatment hope to HER2-positive breast cancer patients, especially those facing the challenge of brain metastases.

In contrast, trastuzumab is an innovative antibody-drug conjugate, which combines anti-HER2 antibodies with chemotherapy drugs and can directly deliver chemotherapy drugs to cancer cells that overexpress the HER2 protein. In the phase II clinical trial of DESTINY-Breast01, detrastuzumab demonstrated significant efficacy in patients with HER2-positive metastatic breast cancer. For patients who had received two or more anti-HER2 treatment regimens, it significantly improved the PFS and OS of patients. In addition, trastuzumab led to robust objective response rates (ORR), with a significant number of patients achieving complete responses, and durability of response is an important treatment outcome.

In general, both tucatinib and trastuzumab play an important role in the treatment of HER2-positive breast cancer The selection of specific drugs should be based on the patient's individual situation, including the presence of metastases, previous treatment history, specific medical history and other factors, and detailed discussion and evaluation with the doctor to determine the most appropriate treatment plan.