The FDA has approved a new treatment for patients with advanced breast cancer that has spread to other parts of the body or cannot be surgically removed. This treatment, marketed under the brand name Datroway, offers hope to individuals with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative tumors who have already undergone hormone therapy and chemotherapy.
Breast cancer remains one of the most common cancers and a leading cause of cancer-related deaths among women in the United States. Approximately 300,000 cases are diagnosed annually, with about 70% classified as HR-positive and HER2-negative. While early-stage breast cancer often responds well to treatment, the prognosis for metastatic cases is significantly poorer, with only about one in three patients surviving beyond five years. This highlights the pressing need for more effective therapies tailored to combat advanced stages of the disease.
Datroway belongs to a class of medications known as antibody-drug conjugates, which are designed to selectively target cancer cells while minimizing damage to healthy tissues. The drug combines a monoclonal antibody, datopotamab, which targets trophoblast cell surface antigen 2 (TROP2)—a protein commonly found in high levels on breast cancer cells—with the chemotherapy agent deruxtecan. This combination allows the drug to attach to cancer cells, delivering the chemotherapy directly inside the cells. The mechanism disrupts the DNA of cancer cells, effectively halting their growth. Datroway is administered intravenously every three weeks.
The effectiveness of Datroway was evaluated in a clinical trial involving 732 patients whose disease had progressed despite previous treatments. These patients were unsuitable for further hormonal therapy and had already undergone one or two rounds of chemotherapy for advanced or metastatic breast cancer. Participants were randomly assigned to receive either Datroway or standard chemotherapy. The results demonstrated that patients treated with Datroway experienced an average progression-free survival of 6.9 months, compared to 4.9 months in the standard chemotherapy group. Additionally, 36% of patients in the Datroway group showed significant improvement in their cancer, compared to 23% in the standard chemotherapy group. The duration of response was also longer for those treated with Datroway, averaging 6.7 months versus 5.7 months in the standard chemotherapy group.
While the drug represents a promising advance in the treatment of advanced breast cancer, it is not without side effects. The most commonly reported adverse effects include mouth sores, nausea, vomiting, constipation, fatigue, hair loss, dry eyes, and eye inflammation (keratitis). Additionally, certain abnormalities in blood cell counts, hemoglobin levels, and liver enzymes were observed in some patients.
Despite these side effects, Datroway offers a significant improvement in outcomes for patients with limited treatment options. Its ability to selectively target cancer cells while sparing healthy tissue represents an important step forward in cancer therapy. By improving progression-free survival and response rates, the drug provides new hope for individuals facing the challenges of advanced HR-positive and HER2-negative breast cancer.
