Tucatinib plus trastuzumab and capecitabine preserves health-related quality of life in patients with metastatic HER2-positive breast cancer.

This study evaluated the impact of tucatinib (Tukysa) in combination with trastuzumab (Herceptin) and capecitabine (Xeloda) on health-related quality of life (HR-QoL) in patients with metastatic human epidermal growth factor (HER2)-positive breast cancer (BC). The data showed that this combination preserved HR-QoL in these patients.

Breast cancer (BC) is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). HER2 is a protein that promotes the growth of some BC. This subtype of BC is called HER2+ BC. Patients with metastatic HER2+ BC that has spread to distant organs have limited treatment options. Trastuzumab and pertuzumab (Perjeta) are targeted therapy drugs used to treat metastatic HER2+ BC. Capecitabine is a chemotherapy drug used to treat BC.

Tucatinib is a type of targeted therapy known as a tyrosine kinase inhibitor (TKI). It is a new drug that targets HER2 and stops the cells from growing and spreading. Tucatinib in combination with trastuzumab and capecitabine significantly improved survival outcomes in patients with advanced HER2+ BC. However, the impact of tucatinib in combination with trastuzumab and capecitabine on HR-QoL in these patients is still unknown.

This study involved 331 women with metastatic HER2+ BC. Patients were randomly assigned to 2 groups. Group 1 included 218 patients who received tucatinib combined with trastuzumab and capecitabine. Group 2 included 113 patients who received a placebo combined with trastuzumab and capecitabine.

The quality of life related to the patients' health was measured by patient questionnaires. The questionnaires took into consideration different elements, such as a person's strength, ability to perform daily activities, sleeping and eating, depression and anxiety, and other medical conditions (pain, discomfort).

Overall, both groups had similar HRQoL scores. Tucatinib combined with trastuzumab and capecitabine reduced the risk of meaningful deterioration by 19% than placebo combined with trastuzumab and capecitabine. The average time to reach deterioration in HRQoL was not reached for patients in group 1 compared to 5.8 months for patients in group 2.

Among patients with brain metastasis, tucatinib combined with trastuzumab and capecitabine reduced the risk of meaningful deterioration by 49% than placebo combined with trastuzumab and capecitabine. In patients with brain metastasis, the average time taken to reach deterioration was not reached for patients in group 1 compared to 5.5 months for patients in group 2.

This study concluded that tucatinib in combination with trastuzumab and capecitabine preserved HRQoL in patients with metastatic HER2+ BC.

This study was sponsored by Seattle Genetics, the manufacturers of tucatinib.