Dr Sara Hurvitz speaks to ecancer about the subgroup analyses from the randomised phase 3 study DESTINY-Breast03. This study investigates the efficacy of trastuzumab deruxtecan (T-DXd; DS-8201a) vs. trastuzumab emtansine (T-DM1) in patients with HER2+ metastatic breast cancer (mBC).

Dr Hurvits initially talks about the background and the methodology of the study. She then discusses the key results obtained from this subgroup analyses.

Dr Hurvitz notes that there was consistent progression-free survival and overall response rate benefit observed across subgroups regardless of hormone receptor status, prior pertuzumab, number of prior lines of therapy, visceral disease, and brain metastases at baseline.

Over 67% of patients by each subgroup benefited or had objective response with T-DXd with most of them exceeding three-quarters of patients having an objective response.

Dr Hurvitz says that overall the safety profiles of T-DXd was manageable and comparable with its known safety profile. Although rates of any treatment-emergent adverse events (TEAEs) and TEAEs of grade 3 or worse were generally similar between arms, exposure-adjusted incident rate were lower with T-DXd compared with T-DM1.

She concludes by saying that the data obtained from this study support T-DXd becoming the standard of care for second-line HER2+ metastatic breast cancer.