A Study of Sacituzumab Tirumotecan (MK-2870) as a Single Agent and in Combination With Pembrolizumab (MK-3475) Versus Treatment of Physician's Choice in Participants With HR+/HER2- Unresectable Locally Advanced or Metastatic Breast Cancer (MK-2870-010)

Purpose

The purpose of this study is to compare sacituzumab tirumotecan as a single agent, and in combination with pembrolizumab, versus Treatment of Physician's Choice (TPC) in participants with hormone receptor positive/human epidermal growth factor receptor-2 negative (HR+/HER2-) unresectable locally advanced, or metastatic, breast cancer. The primary hypotheses are that sacituzumab tirumotecan as a single agent and sacituzumab tirumotecan plus pembrolizumab are superior to TPC with respect to progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) by blinded independent central review (BICR) in all participants.

Condition

  • Breast Neoplasms

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • Has unresectable locally advanced or metastatic centrally-confirmed hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer - Has radiographic disease progression on one or more lines of endocrine therapy for unresectable locally advanced/metastatic HR+/HER2- breast cancer, with one in combination with a CDK4/6 inhibitor - Is a chemotherapy candidate - Has an eastern cooperative oncology group (ECOG) performance status of 0 to 1 assessed within 7 days before randomization - Has adequate organ function - Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy - Participants who are Hepatitis B surface antigen (HBsAg) positive are eligible if they have received HBV antiviral therapy for at least 4 weeks, and have undetectable HBV viral load - Participants with a history of Hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable

Exclusion Criteria

  • Has breast cancer amenable to treatment with curative intent - Has experienced an early recurrence (<6 months after completing adjuvant/neoadjuvant chemotherapy) and therefore is eligible to receive second-line (2L) treatment - Has symptomatic advanced/metastatic visceral spread at risk of rapidly evolving into life-threatening complications - Has received prior chemotherapy for unresectable locally advanced or metastatic breast cancer - Active autoimmune disease that has required systemic treatment in the past 2 years - History of (noninfectious) pneumonitis/interstitial lung disease that requires steroids, or has current pneumonitis/interstitial lung disease - Has an active infection requiring systemic therapy

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Arm A: Sacituzumab tirumotecan 		Participants receive 4 mg/kg of sacituzumab tirumotecan once every 2 weeks (Q2W) via intravenous (IV) infusion until progressive disease or discontinuation.
  • Drug: Sacituzumab tirumotecan
    IV infusion
    Other names:
    • MK-2870
Experimental
Arm B:Pembrolizumab + Sacituzumab tirumotecan 		Participants receive 4 mg/kg of sacituzumab tirumotecan Q2W via IV infusion until progressive disease or discontinuation PLUS 400 mg of pembrolizumab once every 6 weeks (Q6W) via IV infusion for up to 18 administrations (up to ~2 years).
  • Drug: Sacituzumab tirumotecan
    IV infusion
    Other names:
    • MK-2870
  • Biological: Pembrolizumab
    IV infusion
    Other names:
    • MK-3475
    • KEYTRUDA®
Active Comparator
Arm C: Treatment of Physician's Choice (TPC) 		At the physician's discretion, participants receive chemotherapy of 80 mg/m^2 of paclitaxel once every week (Q1W) via IV infusion OR 90 mg/m^2 of paclitaxel once every 4 weeks (Q4W) via IV infusion OR 100 mg/m^2 of nab-paclitaxel Q4W via IV infusion OR 1000 mg/m^2 of capecitabine every 3 weeks (Q3W) orally OR 50 mg/m^2 of liposomal doxorubicin once every 4 weeks (Q4W) via IV infusion, until progressive disease or discontinuation.
  • Drug: Paclitaxel
    IV infusion
    Other names:
    • TAXOL®
  • Drug: Nab-paclitaxel
    IV infusion
    Other names:
    • ABRAXANE®
  • Drug: Capecitabine
    oral tablet
    Other names:
    • XELODA®
  • Drug: Liposomal doxorubicin
    IV infusion
    Other names:
    • DOXIL®

Recruiting Locations

Washington University in St. Louis and nearby locations

Washington University School of Medicine ( Site 0076)
St Louis 4407066, Missouri 4398678 63110
Contact:
Study Coordinator
314-454-8313

More Details

NCT ID
NCT06312176
Status
Recruiting
Sponsor
Merck Sharp & Dohme LLC

Study Contact

Toll Free Number
1-888-577-8839
Trialsites@msd.com