Dr. Iwata Discusses DS-8201a in HER2+ Breast Cancer

Hiroji Iwata, MD, PhD, vice director and chief of Breast Oncology at Aichi Cancer Center Hospital, discusses DS-8201a in HER2-positive breast cancer.

Trastuzumab deruxtecan (DS-8201a) has a breakthrough therapy designation by the FDA for the treatment of patients with HER2-positive, locally advanced, or metastatic breast cancer who have been treated with trastuzumab (Herceptin) and pertuzumab (Perjeta) and have disease progression after ado-trastuzumab emtansine (T-DM1; Kadcyla). Long-term findings from a phase I study presented at the 2018 ASCO Annual meeting showed that this antibody-drug conjugate had antitumor activity in multiple tumor types that expressed varying levels of HER2.

The HER2-positive population is very sensitive to anti-HER2 therapies, says Iwata. Activity with these agents is particularly promising in metastatic breast cancer, however, the HER2-low breast cancer population does not show as impressive results. DS-8201a has a characteristic called the bystander effect, which permeates the membrane, resulting in benefit for both HER2-overexpressing and HER2-low tumors.