HERTHENA-Breast04 Phase 3 trial of Patritumab deruxtecan initiated in patients with metastatic hormone receptor positive, HER2 negative breast cancer previously treated with endocrine therapy

CAR-T Digest - August 2020

Weekly Digest - August 2025

27 August 2025: HERTHENA-Breast04 Phase 3 trial of Patritumab deruxtecan initiated in patients with metastatic hormone receptor positive, HER2 negative breast cancer previously treated with endocrine therapy

Daiichi Sankyo and Merck have started the HERTHENA-Breast04 Phase 3 trial, marking the first patient treated with patritumab deruxtecan for HR-positive, HER2-negative metastatic breast cancer
This type of breast cancer is particularly challenging, as patients progressing after endocrine and CDK4/6 therapies often face poor survival outcomes, with only about 30% of patients initially diagnosed with advanced disease or having metastatic progression are expected to live five years following diagnosis
Earlier studies, including ICARUS-Breast01 and a Phase 1/2 trials, already showed encouraging results, suggesting real potential for this therapy
Building on that promise, the new trial reflects the companies’ commitment to offering fresh hope and innovative treatments for patients battling one of the toughest forms of breast cancer