Key clinical point: Trastuzumab deruxtecan was superior to trastuzumab emtansine in reducing the risk for disease progression or death in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer who had been previously treated with trastuzumab and a taxane.
Major finding: At 12 months, 75.8% of patients in the trastuzumab deruxtecan group vs. 34.1% patients in the trastuzumab emtansine group achieved progression-free survival (hazard ratio for disease progression/death from any cause 0.28; P < .001). The incidence of drug-related adverse events of any grade was 98.1% with trastuzumab deruxtecan and 86.6% with trastuzumab emtansine.
Study details: This interim analysis of the phase 3 DESTINY-Breast03 trial included 524 patients with HER2+ metastatic breast cancer who were randomly assigned to receive trastuzumab deruxtecan or trastuzumab emtansine after their disease progressed having taken trastuzumab and a taxane.
Disclosures: This study was supported by Daiichi Sankyo and AstraZeneca. Four authors declared being employees or stockholders of Daichi Sankyo and one author declared being an employee of AstraZeneca. The other authors reported ties with various sources.
Source: Cortés J et al. Trastuzumab deruxtecan versus trastuzumab emtansine for breast cancer. N Engl J Med. 2022;386:1143-1154 (Mar 24). Doi: 10.1056/NEJMoa2115022