DESTINY-Breast03: Improving Outcomes in Metastatic HER2-Positive Breast Cancer

The treatment of metastatic, HER2-positive breast cancer has improved dramatically in recent years as more effective therapies have been introduced. The standard first-line therapy remains a taxane combined with dual HER2 targeting with trastuzumab and pertuzumab, the so-called Cleopatra regimen. On disease progression, most patients would receive the antibody-drug conjugate trastuzumab-emtansine (T-DM1). Thereafter, a variety of HER2 therapies could be considered, including recently approved trastuzumab deruxtecan (T-DXd) and the triplet of trastuzumab, tucatinib, and capecitabine.

The DESTINY-Breast03 study is an industry-sponsored, phase 3, multicenter randomized trial comparing T-DXd to T-DM1 in patients with HER2-positive metastatic bre…