About 50% of all primary breast cancers exhibit low expression of human epidermal growth factor receptor 2 (HER2) (HER2-low). 1 Such tumors do not respond to traditional HER2 targeting agents like trastuzumab, T-DM1. 2,3 However, antibody–drug conjugates (ADCs) can target these low HER2 levels. The ADCs employ cleavable linkers and a higher drug-to-antibody ratio. 4 In addition, they exhibit a higher bystander killer effect in contrast to T-DM1. 4 One such ADC, trastuzumab deruxtecan, is currently under investigation in the DESTINY Breast04 trial.
5 The trial is being conducted to compare the efficacy of trastuzumab deruxtecan against the physician’s choice of chemotherapy in patients with HER2-low metastatic unresectable breast cancer. The trial is still ongoing, and the initial results with trastuzumab deruxtecan look promising. Table 1 summarizes the study details. Table 1. Details…
