Datopotamab Deruxtecan: New antibody-drug conjugate for breast cancer

Each year, approximately 74,500 women and 700 men in Germany are newly diagnosed with breast cancer . In 75 percent of cases, the tumor is hormone receptor-positive. About 15 percent of tumors express the receptor for the growth factor HER2. If the tumor has hormone receptors but no HER2 receptors, it is referred to as HR ⁺ / ^HER2- breast cancer.

Datopotamab deruxtecan (Datroway® 100 mg powder for concentrate for solution for infusion, Daiichi Sankyo) is intended for the treatment of patients with this type of cancer. The tumor must be inoperable or metastatic, and patients must have previously received endocrine therapy and at least one line of chemotherapy in advanced stages. The new drug is administered as monotherapy at a dose of 6 mg/kg body weight. Patients weighing more than 90 kg receive a maximum of 540 mg.

As an antibody-drug conjugate, datopotamab deruxtecan binds to trophoblast cell surface antigen 2 (Trop-2) on tumor cells, is internalized, and broken down intracellularly into its components. The active ingredient, deruxtecan (DXd), is a topoisomerase I inhibitor that causes DNA damage and ultimately apoptotic cell death. Sacituzumab govitecan (Trodelvy®) has an identical mechanism of action. When the latter drug came onto the market in 2021, it was a novel approach, which is why the Federal Joint Committee (G-BA) attested to its significant added benefit .

Treatment with datopotamab deruxtecan is administered intravenously every three weeks and continued until disease progression or unacceptable toxicity occurs. Various side effects may require an extension of the dosing interval and a dose reduction to initially 4 mg/kg (maximum 360 mg) and ultimately 3 mg/kg (maximum 270 mg). Once the dose has been reduced, it should not be increased again.