RecruitingPhase 3

A Clinical Study of Sacituzumab Tirumotecan (Sac-TMT, MK-2870) in People With Breast Cancer (MK-2870-032)

United States, Argentina, Australia2,400 participantsStarted 2025-06-30

Plain-language summary

Researchers are looking for new ways to treat types of breast cancer that are both: * High-risk, which means the cancer may have a higher chance of getting worse or coming back after treatment * Early-stage, which means the cancer is in the breast or the lymph nodes around the breast The 2 types of breast cancer in this study are triple-negative breast cancer (TNBC) and hormone receptor (HR)-low positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer. These cancers have zero or a low amount of a protein called HER2 and other proteins that attach to the hormones estrogen or progesterone. Sacituzumab tirumotecan (also known as sac-TMT or MK-2870), the study medicine, is a type of targeted therapy. A targeted therapy is a treatment that works to control how specific types of cancer cells grow and spread. The main goals of this study are to learn if people who receive sac-TMT, pembrolizumab, and chemotherapy: * Have fewer cancer cells found in the tumors and lymph nodes removed during surgery compared to those who receive only pembrolizumab and chemotherapy * Live longer without the cancer growing, spreading, or coming back compared to people who receive only pembrolizumab with chemotherapy

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Has previously untreated high-risk, early-stage, non-metastatic (M0) breast cancer (BC), defined as any of the following combined primary tumor (T) and regional lymph node (N) staging per AJCC 8th edition criteria as assessed by the physician investigator based on radiological and/or clinical assessment: * cT1c, N1-N2 * cT2, N0-N2 * cT3, N0-N2 * cT4a-d, N0-N2 * The participant must have a centrally confirmed diagnosis of BC that is triple-negative or HR-low+/HER2- (defined as estrogen receptor (ER)-low+ expression in 1% to 10% cells and HER2- as by the most recent American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. * Provides a core needle biopsy from the primary breast tumor at screening to the central laboratory. * Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 performed within 28 days before Cycle1 Day 1 (C1D1). * Demonstrates adequate organ function. Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Metastatic (Stage IV) breast cancer or clinical node stage 3 (cN3) nodal involvement * Has received any prior treatment, including radiation, systemic therapy,and/or definitive surgery for currently diagnosed breast cancer * Has undergone excisional biopsy of the primary tumor, axillary lymph node dissection, and/or axillary sentinel lymph node biopsy p…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Percentage of Participants with Pathological Complete Response (pCR) at the Time of Definitive Surgery

Timeframe: Up to approximately 30 weeks

Event-Free Survival (EFS)

Timeframe: Up to approximately 92 months

Trial details

NCT IDNCT06966700

SponsorMerck Sharp & Dohme LLC

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2033-03-23

Contact for this trial

Toll Free Number

1-888-577-8839 Trialsites@msd.com

View on ClinicalTrials.gov More Breast Neoplasms trials