An intravenous HER2-targeted monoclonal antibody–drug conjugate (ADC) dosed 5.4 mg/kg every 3 weeks; binds HER2 (ERBB2) on tumor cells, is internalized, and releases a DNA-damaging cytotoxic payload that inhibits proliferation, leading to tumor cell death; designed for HER2-expressing and HER2-low solid tumors.