Researchers at the University of California San Diego School of Medicine have identified a promising new therapy for triple-negative breast cancer (TNBC), which is among the most aggressive and difficult-to-treat forms of the disease. Their approach employs an antibody-drug conjugate -- a delivery system that uses an antibody to identify cancer cells and deliver a highly potent chemotherapy directly into those cells without harming surrounding healthy tissue. Antibody-drug conjugates make it possible to use chemotherapy drugs that are too toxic to deliver on their own, offering a promising avenue for treating the most difficult cancers.

In 2025, an estimated 316,950 women and 2,800 men will be diagnosed with invasive breast cancer. TNBC accounts for about 10-15% of all breast cancer cases, and it is widely considered the most difficult breast cancer subtype to treat. This is because TNBC tends to grow and spread more quickly than other forms of breast cancer, and it typically fails to respond to therapies that work in other subtypes, such as hormonal therapies. As a result, survival rates for TNBC tend to be lower than for other breast cancers. Additionally, TNBC disproportionately affects younger women, Black women and those with certain genetic mutations.