NCT06797635

Study of Patritumab Deruxtecan Plus Pembrolizumab With Other Anticancer Agents in Participants With High-Risk Early-Stage Triple-Negative or Hormone Receptor-Low Positive/HER-2 Negative Breast Cancer (MK-1022-010, HERTHENA-Breast-03)

An Open-label Randomized Phase 2 Study to Evaluate Safety and Efficacy of Patritumab Deruxtecan Plus Pembrolizumab Administered Either Before or After Carboplatin/Paclitaxel Plus Pembrolizumab Compared With Pembrolizumab in Combination With Chemotherapy Followed by Surgery and Adjuvant Pembrolizumab for High-Risk Early-Stage Triple-Negative or Hormone Receptor-Low Positive/Human Epidermal Growth Factor Receptor-2 Negative Breast Cancer (HERTHENA-Breast03)

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 372 (estimated)
• Sponsor: Merck Sharp & Dohme LLC · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Researchers are looking for new ways to treat triple-negative breast cancer (TNBC) and hormone receptor (HR) low positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer. The main goals of this study are to learn: * About the safety of the study treatments and if people tolerate them * If people who receive patritumab deruxtecan, pembrolizumab, and chemotherapy before surgery have fewer cancer cells removed during surgery compared to those who receive only pembrolizumab (pembro) and chemotherapy.

Conditions

• Breast Neoplasms
• Breast Cancer

Interventions

Type	Name	Description
BIOLOGICAL	Patritumab deruxtecan	Administered via IV infusion as neoadjuvant treatment
BIOLOGICAL	Pembrolizumab	Administered via IV infusion as neoadjuvant treatment in Part 1 and via IV infusion as neoadjuvant and adjuvant treatment in Part 2
DRUG	Paclitaxel	Administered via IV infusion as neoadjuvant treatment
DRUG	Carboplatin	Administered via IV infusion as neoadjuvant treatment
DRUG	Doxorubicin hydrochloride	Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2
DRUG	Epirubicin hydrochloride	Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2
DRUG	Cyclophosphamide	Administered via IV infusion as neoadjuvant treatment in Arm C and an option for adjuvant treatment for participants with residual disease in Arms A and B in Part 2
DRUG	Capecitabine	Administered via oral tablets as an option for adjuvant treatment for participants with residual disease in Part 2
DRUG	Olaparib	Administered via oral tablets as an option for adjuvant treatment for participants with germline BRCA mutations and residual disease in Part 2

Timeline

• Start date: 2025-03-20
• Primary completion: 2029-12-31
• Completion: 2034-12-31
• First posted: 2025-01-28
• Last updated: 2026-03-13

Locations

17 sites across 4 countries: United States, South Korea, Spain, Taiwan

Regulatory

• FDA-regulated drug study