Jan. 21, 2025 -- The FDA has approved a new treatment for patients with a common form of breast cancer that has spread to other parts of the body or cannot be surgically removed.
The drug, known as datopotamab deruxtecan but marketed under the brand name Datroway, is intended to treat hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative tumors that have already been treated with hormone therapy and chemotherapy.
Breast cancer is the most common cancer (after skin cancer) and the second leading cause of cancer death among women in the United States. Each year about 300,000 cases of breast cancer are diagnosed, with about 70% being HR-positive and HER2-negative. While early-stage cases often respond well to treatment, only about 1 in 3 people with metastatic breast cancer survive more than 5 years, highlighting the urgent need for improved tumor-targeted therapies.
Datroway belongs to a class of medicines called antibody-drug conjugates and is designed to target cancer cells while sparing the healthy ones. It combines a monoclonal antibody, datopotamab, that targets trophoblast cell surface antigen 2 (TROP2), a protein commonly found in high levels on breast cancer cells, with the chemotherapy drug deruxtecan. Once attached to cancer cells, it releases the drug directly inside, disrupting the cells’ DNA and stopping their growth. Developed by AstraZeneca and Daiichi Sankyo, Datroway is given as an IV every 3 weeks.
The effectiveness of the drug was evaluated in a clinical trial involving 732 patients whose disease had worsened, were unsuitable to receive more hormonal therapy, and had already received one or two rounds of chemotherapy for advanced or metastatic cancer. Patients were randomly assigned to receive either Datroway or standard chemotherapy. Results showed that patients treated with Datroway lived for about 6.9 months on average without their cancer worsening, compared to 4.9 months for the standard chemotherapy group. Cancer improved in 36% of patients in the Datroway group, compared to 23% in the standard chemotherapy group, with responses lasting for an average of 6.7 months versus 5.7 months seen in the group receiving standard chemotherapy.
The most common side effects included mouth sores, nausea, vomiting, constipation, tiredness, hair loss, dry eyes, eye inflammation (keratitis), and certain abnormalities in blood cell counts, hemoglobin levels, and liver enzymes.
