Merck & Co. Inc. Initiates Phase 3 HERTHENA-Breast04 Trial for Patritumab Deruxtecan in Treating Advanced HR Positive, HER2 Negative Breast Cancer
Merck & Co. Inc. has initiated the HERTHENA-Breast04 phase 3 trial to evaluate the efficacy and safety of patritumab deruxtecan in patients with advanced HR positive, HER2 negative breast cancer. This trial follows promising results from previous studies and aims to provide new treatment options for patients who have not responded to existing therapies. The drug, developed jointly with Daiichi Sankyo, targets HER3 and addresses an unmet medical need in this challenging cancer type. Results from the trial are pending.
Merck & Co. Inc. has announced the initiation of the HERTHENA-Breast04 phase 3 trial, investigating the efficacy and safety of patritumab deruxtecan (HER3-DXd) in patients with unresectable locally advanced or metastatic hormone receptor (HR) positive, HER2 negative breast cancer who have experienced disease progression following endocrine and CDK4/6 inhibitor therapy. The trial follows promising results from the ICARUS-Breast01 study and a phase 1⁄2 trial previously published in the Journal of Clinical Oncology in June 2022. Patritumab deruxtecan, an antibody drug conjugate (ADC) targeting HER3, was discovered by Daiichi Sankyo and is being developed jointly by Daiichi Sankyo and Merck. The study aims to address the unmet need for new treatment options for this challenging type of breast cancer. Results from this phase 3 trial are not yet available. Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Merck & Co. Inc. published the original content used to generate this news brief via Business Wire (Ref. ID: 20250827189567) on August 27, 2025, and is solely responsible for the information contained therein. © Copyright 2025 - Public Technologies (PUBT)
