Key clinical point: Trastuzumab deruxtecan demonstrated superior efficacy over trastuzumab emtansine as second-line treatment in patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) with or without brain metastases.
Major finding: Trastuzumab deruxtecan led to significantly longer median progression-free survival (15.0 vs 3.0 months; hazard ratio 0.25; 95% CI 0.13-0.45) and higher systemic (67.4% vs 20.5%) and intracranial (65.7% vs 34.3%) objective response rates than trastuzumab emtansine in patients with brain metastases. Outcomes were similar in patients without brain metastases.
Study details: This exploratory analysis of the phase 3 DESTINY-Breast03 trial included 524 patients with HER2+ metastatic BC with or without brain metastases who were randomly assigned to receive trastuzumab deruxtecan or trastuzumab emtansine after their disease progressed with trastuzumab and taxane treatment.
Disclosures: This study was supported by Daiichi Sankyo and AstraZeneca. Six authors declared being current or former employees or holding stock or stock options of Daiichi Sankyo or AstraZeneca. Several authors declared having ties to various sources, including Daiichi Sankyo and AstraZeneca.
Source: Hurvitz SA, Kim SB, Chung WP, et al. Trastuzumab deruxtecan versus trastuzumab emtansine in HER2-positive metastatic breast cancer patients with brain metastases from the randomized DESTINY-Breast03 trial . ESMO Open. 2024;109294 (Apr 24). doi: 10.1016/j.esmoop.2024.102924 Source