A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)

NCT ID: NCT06979596

Last Updated: 2025-11-10

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE2

Total Enrollment

250 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-08-11

Study Completion Date

2027-11-04

Brief Summary

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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.

Detailed Description

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Conditions

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Malignant Neoplasm

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

SINGLE

Outcome Assessors

Study Groups

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Treatment of Physician's Choice

Participants with endometrial cancer will receive the physician's choice of either 80 mg megestrol acetate/medroxyprogesterone acetate twice daily, or alternating between 80 mg megestrol acetate twice daily for three weeks and 20 mg tamoxifen twice daily for three weeks, or 2.5 mg letrozole once daily. Participants will receive treatment until one of the conditions for discontinuation of study intervention is met.

Group Type EXPERIMENTAL

Megestrol acetate/Medroxyprogesterone acetate

Intervention Type DRUG

Tablet for oral administration.

Tamoxifen

Intervention Type DRUG

Tablet for oral administration.

Letrozole

Intervention Type DRUG

Tablet for oral administration.

Fulvestrant or Exemestane

Participants with breast cancer receive endocrine therapy of the physician's choice: either 500 mg of fulvestrant on Day 1 and Day 15 of Cycle 1 and Day 1 of every cycle thereafter (cycles are 28 days in length) or 25 mg of exemestane once daily (QD). Participants will receive treatment until one of the conditions for discontinuation of study intervention is met.

Group Type EXPERIMENTAL

Fulvestrant

Intervention Type DRUG

Administered via intramuscular injection.

Exemestane

Intervention Type DRUG

Tablet for oral administration.

Observation (No Treatment)

Participants with ovarian cancer will be observed but will receive no treatment for the duration of the study.

Group Type NO_INTERVENTION

No interventions assigned to this group

MK-5684 and Supportive Adrenal Therapy (SAT)

Participants with breast cancer, ovarian cancer, or endometrial cancer will receive 5 mg of MK-5684 orally twice daily. Participants will also receive fludrocortisone/fludrocortisone acetate starting at 0.1 mg orally, and dexamethasone/dexamethasone acetate starting at 1 mg orally; both will be adjusted individually during the study. Participants will receive treatment until one of the conditions for discontinuation of study intervention is met.

Group Type EXPERIMENTAL

MK-5684

Intervention Type DRUG

Tablet for oral administration.

Fludrocortisone/ Fludrocortisone acetate

Intervention Type DRUG

Tablet for oral administration.

Dexamethasone/Dexamethasone acetate

Intervention Type DRUG

Tablet for oral administration.

Rescue Medications

Intervention Type DRUG

Hydrocortisone or hydrocortisone/hydrocortisone acetate administered via intramuscular injection as rescue medication.

Interventions

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MK-5684

Tablet for oral administration.

Intervention Type DRUG

Fludrocortisone/ Fludrocortisone acetate

Tablet for oral administration.

Intervention Type DRUG

Dexamethasone/Dexamethasone acetate

Tablet for oral administration.

Intervention Type DRUG

Rescue Medications

Hydrocortisone or hydrocortisone/hydrocortisone acetate administered via intramuscular injection as rescue medication.

Intervention Type DRUG

Fulvestrant

Administered via intramuscular injection.

Intervention Type DRUG

Exemestane

Tablet for oral administration.

Intervention Type DRUG

Megestrol acetate/Medroxyprogesterone acetate

Tablet for oral administration.

Intervention Type DRUG

Tamoxifen

Tablet for oral administration.

Intervention Type DRUG

Letrozole

Tablet for oral administration.

Intervention Type DRUG

Other Intervention Names

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Opevesostat

Eligibility Criteria

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Inclusion Criteria

* Cohort A:

* 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.
* Cohort B:

* 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.
* Cohort C:

* Histologically confirmed diagnosis of primary advanced or recurrent low-grade endometrioid carcinoma (eg, Federation of Gynecology and Obstetrics \[FIGO\] Grade 1/2, or well/moderately differentiated).
* Treatment naïve or has received up to 1 prior line of platinum-based therapy in either the advanced/metastatic OR adjuvant/neoadjuvant setting.
* All Cohorts :

* Participants who have AEs due to previous anticancer therapies must have recovered to ≤Grade 1 or baseline.
* Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy.
* Participants who are Hepatitis B surface antigen positive are eligible if they have received Hepatitis B virus (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

* Cohort A:

* Breast cancer amenable to treatment with curative intent.
* Has advanced/metastatic, symptomatic visceral spread at risk of rapidly evolving into life-threatening complications, such as lymphangitic lung metastases, radiographic evidence of intratumoral cavitation or invasion/infiltration of a major blood vessel, bone marrow replacement, carcinomatous meningitis, significant symptomatic liver metastases, symptomatic pericardial effusion, symptomatic peritoneal carcinomatosis, or the need to achieve rapid symptom control.
* Cohort B:

* Has nonepithelial cancers (germ cell tumors and sex cord-stromal tumors), borderline tumors (low malignant potential), mucinous, seromucinous that is predominantly mucinous, malignant Brenner's tumor, low-grade serous, low-grade endometrioid, and undifferentiated carcinoma.
* Has platinum-resistant ovarian cancer (defined as disease that has progressed per radiographic imaging within 180 days after the last dose of first-line \[1L\] platinum-based therapy) or platinum-refractory ovarian cancer (defined as disease that has progressed per radiographic imaging while receiving or within 28 days of the last dose of 1L platinum based therapy).
* Is a candidate for curative-intent surgery or curative-intent radiotherapy for ovarian cancer.
* Cohort C:

* Has high-grade (FIGO Grade 3 or poorly differentiated) endometrioid carcinoma and nonendometrioid histologies of any type (including serous, clear cell, mixed, carcinosarcoma), and neuroendocrine tumors are not eligible. Uterine mesenchymal tumors such as an endometrial stromal sarcoma, leiomyosarcoma, or other types of pure sarcomas, and adenosarcomas are not eligible.
* Is a candidate for curative-intent surgery or curative-intent radiotherapy.
* All Cohorts:

* Has confirmed or suspected adrenal metastases.
* Has known difficulty in tolerating oral medications, unable to swallow orally administered medication, or conditions which would impair absorption of oral medications.
* Has any prior history or current condition of adrenal insufficiency.
* HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease.
* Has received a live or live-attenuated vaccine within 30 days before the first dose of study intervention. Administration of killed vaccines is allowed.
* Has a known additional malignancy that is progressing or has required active treatment within the past 3 years.
* Has known active central nervous system metastases and/or carcinomatous meningitis.
* Has a history of stem cell/solid organ transplant.
* Has not adequately recovered from major surgery or has ongoing surgical complications.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Merck Sharp & Dohme LLC

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Medical Director

Role: STUDY_DIRECTOR

Merck Sharp & Dohme LLC

Locations

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Alaska Womens Cancer Care ( Site 0037)

Anchorage, Alaska, United States

Site Status RECRUITING

Mount Sinai Cancer Center ( Site 0009)

Miami Beach, Florida, United States

Site Status RECRUITING

TRIALS 365 ( Site 0022)

Shreveport, Louisiana, United States

Site Status RECRUITING

Mary Lanning Healthcare ( Site 0019)

Hastings, Nebraska, United States

Site Status RECRUITING

Hospital Aleman ( Site 0301)

Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina

Site Status RECRUITING

Centro Medico Dr. Doreski - Fundación Respirar ( Site 0302)

Buenos Aires, Buenos Aires F.D., Argentina

Site Status RECRUITING

Institut Català d'Oncologia - L'Hospitalet-Medical Oncology ( Site 2000)

L'Hospitalet de Llobregat, Barcelona, Spain

Site Status RECRUITING

CHUAC-Complejo Hospitalario Universitario A Coruña ( Site 2003)

A Coruña, La Coruna, Spain

Site Status RECRUITING

Clinica Universitaria Navarra - Madrid ( Site 2004)

Madrid, Madrid, Comunidad de, Spain

Site Status RECRUITING

Hospital Universitario Ramón y Cajal-Medical Oncology ( Site 2002)

Madrid, Madrid, Comunidad de, Spain

Site Status RECRUITING

HOSPITAL UNIVERSITARIO QUIRONSALUD MADRID-ONCOLOGIA MEDICA ( Site 2001)

Madrid, , Spain

Site Status RECRUITING

Taichung Veterans General Hospital ( Site 1004)

Taichung, , Taiwan

Site Status RECRUITING

National Cheng Kung University Hospital ( Site 1003)

Tainan, , Taiwan

Site Status RECRUITING

Mackay Memorial Hospital ( Site 1002)

Taipei, , Taiwan

Site Status RECRUITING

University Hospitals Sussex NHS Foundation Trust ( Site 2301)

East Sussex, Brighton And Hove, United Kingdom

Site Status RECRUITING

The Royal Cornwall Hospital ( Site 2306)

Truro, Cornwall, United Kingdom

Site Status RECRUITING

The Christie NHS Foundation Trust ( Site 2300)

Manchester, , United Kingdom

Site Status RECRUITING

Countries

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United States Argentina Spain Taiwan United Kingdom

Central Contacts

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Toll Free Number

Role: CONTACT

Phone: 1-888-577-8839

Email: [email protected]

Facility Contacts

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Study Coordinator

Role: primary

Study Coordinator

Role: primary

Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

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Study Coordinator

Role: primary

Related Links

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https://www.merckclinicaltrials.com/

Merck Clinical Trials Information

Other Identifiers

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2024-519563-18-00

Identifier Type: REGISTRY

Identifier Source: secondary_id

U1111-1315-5430

Identifier Type: REGISTRY

Identifier Source: secondary_id

MK-5684-015

Identifier Type: OTHER

Identifier Source: secondary_id

OMAHA-015

Identifier Type: OTHER

Identifier Source: secondary_id

5684-015

Identifier Type: -

Identifier Source: org_study_id