Dr. Westbrook on Combatting Tumor Heterogeneity in HER2+ Breast Cancer

Kelly E. Westbrook, MD, assistant professor, Duke University School of Medicine, discusses combatting tumor heterogeneity in patients with HER2-positive breast cancer.

Ado-trastuzumab emtansine (T-DM1; Kadcyla) is one antibody-drug conjugate currently in clinical trials with a high affinity for the HER2 receptor that treats HER2-positive cells with minimal toxicity because of low levels of T-DM1 systemically, explains Westbrook. However, it does not have the ability to target patients with low expression of HER2 cells, says Westbrook.

There are many interesting transitions in the antibody-drug conjugate world, including trying to create antibody-drug conjugates that will have an affinity for low levels of HER2 cells or a bystander effect, according to Westbrook. Traditional therapy is not affected by tumor heterogeneity because most HER2-targeted therapies are coupled with a chemotherapy backbone, which helps navigate the tumor heterogeneity, concludes Westbrook.