NCT07060807

A Clinical Study of Patritumab Deruxtecan to Treat Breast Cancer (MK-1022-016)

An Open-label, Randomized, Phase 3 Study to Evaluate Patritumab Deruxtecan Monotherapy Versus Treatment of Physician's Choice in Hormone Receptor-positive, HER2-negative Unresectable Locally Advanced or Metastatic Breast Cancer (HERTHENA-Breast04)

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 1,000 (estimated)
• Sponsor: Merck Sharp & Dohme LLC · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Researchers are looking for other ways to treat breast cancer (BC) that is hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) and either unresectable locally advanced or metastatic. * HR positive (HR+) means the cancer cells have proteins that attach to estrogen or progesterone (hormones) which help the cancer to grow and spread * HER2 negative (HER2-) means the cancer cells have a low amount of a protein called HER2 * Unresectable locally advanced means the cancer cannot be completely removed by surgery and has spread into nearby tissue or muscles * Metastatic means the cancer has spread to other parts of the body Treatment for this type of breast cancer usually includes endocrine therapy (ET) and sometimes a second treatment. The main goal of this study is to learn if people who receive patritumab deruxtecan (also known as HER3-DXd and MK-1022) live longer overall or without the cancer growing/spreading, compared to people who receive chemotherapy or a different drug called trastuzumab deruxtecan.

Conditions

• Breast Neoplasms

Interventions

Type	Name	Description
BIOLOGICAL	Patritumab deruxtecan	Administered via intravenous (IV) infusion
DRUG	Paclitaxel	Administered via IV infusion
DRUG	Nab-paclitaxel	Administered via IV infusion
DRUG	Capecitabine	Administered via oral tablets
DRUG	Liposomal doxorubicin	Administered via IV infusion
BIOLOGICAL	Trastuzumab deruxtecan	Administered via IV infusion

Timeline

• Start date: 2025-07-21
• Primary completion: 2033-07-14
• Completion: 2033-07-14
• First posted: 2025-07-11
• Last updated: 2026-04-16

Locations

168 sites across 24 countries: United States, Argentina, Australia, Brazil, Canada, Chile, China, Colombia, France, Germany, Greece, Hong Kong, Hungary, Israel, Italy, Japan, Mexico, Poland, South Korea, Spain, Taiwan, Thailand, Turkey (Türkiye), United Kingdom

Regulatory

• FDA-regulated drug study