The American Cancer Society states breast cancer is the second most common cancer and second leading cause of death among women in the United States, despite improvements in early detection, treatment, and survival. The preferred treatment involves targeted therapy, which uses selective antibodies and leaves normal cells relatively unharmed.

Conventional antibody-drug conjugate technology for breast cancer, however, is limited due to safety concerns about bonding that leads to low antibody concentration. A novel drug-delivery system combines cancer- specific targeting mechanisms with anti-cancer agents without chemical modifications. The conjugate is comprised of an ATP binding domain (ABD), an anti-cancer drug, and a scFv antibody that targets a specific receptor on the surface of a cancer cell. The fused protein captures an anti- cancer agent without creating a chemical bond and then delivers it to a cancer cell. The drug carrier also has intrinsic anti-proliferative properties that increase drug efficacy by depriving the cancer cell of ATP.