A Novel Treatment for Triple-Negative Breast Cancer?

The introduction of ado-trastuzumab emtansine (T-DM1) as a targeted therapy for patients with HER2-positive breast cancer raised the possibility that fusion compounds could be developed to enhance antitumor activity and minimize toxicity in other subtypes of breast cancer. A key challenge is to identify a unique tumor-cell target for an antibody.

One potential target is glycoprotein NMB (gpNMB), a type I transmembrane protein expressed intracellularly and on the cell surface in breast cancer, melanoma, and other tumor types. Cell-surface gpNMB is cleaved to produce a biologically active molecule that mediates cell adhesion, cell growth/differentiation, and immune modulation. The gpNMB protein is overexpressed in more than one third of triple…