A monoclonal antibody directed against the Notch receptor with potential antineoplastic activity. Tarextumab binds to Notch on the cell surface, thereby inhibiting Notch-mediated signaling and gene transcription, which may impede tumor angiogenesis. Notch receptors are important for cell-cell communication, which involves gene regulation mechanisms that control multiple cell differentiation processes during embryonic and adult life. Dysregulated Notch signaling is implicated in many diseases including T-ALL (T-cell acute lymphoblastic leukemia), CADASIL (cerebral autosomal dominant arteriopathy with sub-cortical infarcts and leukoencephalopathy), MS (multiple sclerosis), and many other disease states.