NCT06979596 · Merck Sharp & Dohme LLC
A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)
What this study is about
Researchers want to learn if MK-5684 (the study medicine) can treat breast cancer, ovarian cancer, and endometrial cancer. MK-5684, the study medicine, is designed to treat cancer by blocking the body from making steroid hormones. Researchers will compare MK-5684 to the standard treatments for each cancer type in this study.
View original scientific description
Researchers want to learn if MK-5684 (the study medicine) can treat breast cancer, ovarian cancer, and endometrial cancer. MK-5684, the study medicine, is designed to treat cancer by blocking the body from making steroid hormones. Researchers will compare MK-5684 to the standard treatments for each cancer type in this study. The goal of this study is to learn if people who receive MK-5684 live longer without the cancer growing or spreading compared to people who receive a standard treatment.
Interventions
DRUG
Opevesostat
Tablet for oral administration.
DRUG
Fludrocortisone/ Fludrocortisone acetate
Tablet for oral administration.
DRUG
Dexamethasone/Dexamethasone acetate
Tablet for oral administration.
DRUG
Rescue Medications
Hydrocortisone or hydrocortisone/hydrocortisone acetate administered via intramuscular injection as rescue medication.
DRUG
Fulvestrant
Administered via intramuscular injection.
DRUG
Exemestane
Tablet for oral administration.
DRUG
Megestrol acetate/Medroxyprogesterone acetate
Tablet for oral administration.
DRUG
Tamoxifen
Tablet for oral administration.
DRUG
Letrozole
Tablet for oral administration.
Primary outcome measures
Progression-Free Survival (PFS) - All Cohorts
Time frame: Up to approximately 2 years
For all cohorts, PFS is defined as the time from randomization to the first documented progressive disease (PD) or death due to any cause, whichever occurs first as assessed by Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1). PD is defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions is also considered PD. PFS as assessed by blinded independent central review (BICR) will be presented.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The main inclusion criteria include but are not limited to the following:
- Has a diagnosis of hormone receptor positive/Human Epidermal Growth Factor Receptor 2 negative (HR+/HER2-) invasive breast carcinoma that is either locally advanced disease not amenable to resection with curative intent (herein called unresectable) or metastatic disease not treatable with curative intent.
- Has experienced disease progression on or after at least 1 prior endocrine-based therapy in the metastatic setting.
- Has histologically confirmed high-grade epithelial (including high-grade serous or predominantly serous, high-grade endometrioid, malignant mixed Müllerian tumors \[carcinosarcoma\], or clear cell) ovarian, fallopian tube, or primary peritoneal carcinoma.
- Has received between 4 to 8 cycles of platinum-based doublet chemotherapy in third-line (3L) setting for ovarian cancer.
- Histologically confirmed diagnosis of primary
Where
- Anchorage, Alaska
- Miami Beach, Florida
- Shreveport, Louisiana
- Hastings, Nebraska
- Hackensack, New Jersey
- New York, New York
- Columbus, Ohio
- Houston, Texas
- San Antonio, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 17, 2026 · Source of record for eligibility and locations