Malignant NeoplasmPhase 2NCT06979596
A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)
A Phase 2 study testing Opevesostat, Fludrocortisone/ Fludrocortisone acetate and Dexamethasone/Dexamethasone acetate in people with Malignant Neoplasm, run by Merck Sharp & Dohme LLC at 60 sites in 13 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Malignant Neoplasm
- What is being tested?
- Opevesostat, Fludrocortisone/ Fludrocortisone acetate and Dexamethasone/Dexamethasone acetate
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 250 participants
- Where
- 60 sitesin 13 countries
- Study dates
- 11 Aug 2025to 4 Nov 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The main inclusion criteria include but are not limited to the following:
- 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 and received either, 1 line of an approved protocol-specified combination endocrine-based therapy, or 2 or more lines of protocol-specified 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.
Show all 15Show fewer
- 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.
Who cannot join
- The main exclusion criteria include but are not limited to the following:
- 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.
Show all 21Show fewer
- 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.
Trial locations and contacts
60 sites in 13 countries. Contact the study team or a site near you to ask about taking part.
60 sites in 13 countries
United States10 sites, 10 recruiting
- Recruiting
Alaska Womens Cancer Care ( Site 0037)
Anchorage, Alaska, 99508
Study Coordinator, 907-562-2211
- Recruiting
The James Cancer Hospital and Solove Research Institute at The Ohio State University Comprehensive C ( Site 0008)
Columbus, Ohio, 43210
Study Coordinator, (614) 293-8000
- Recruiting
John Theurer Cancer Center at Hackensack University Medical Center ( Site 0021)
Hackensack, New Jersey, 07601
Study Coordinator, 551-996-5855
- Recruiting
Mary Lanning Healthcare ( Site 0019)
Hastings, Nebraska, 68901
Study Coordinator, 402-463-4521
- Recruiting
Baylor College of Medicine Medical Center ( Site 0004)
Houston, Texas, 77030
Study Coordinator, 713-798-2000
- Recruiting
Harris Health System ( Site 0040)
Houston, Texas, 77054
Study Coordinator, 713-798-1694
- Recruiting
Mount Sinai Cancer Center ( Site 0009)
Miami Beach, Florida, 33140
Study Coordinator, 305-674-2625
- Recruiting
Rockefeller Outpatient Pavilion ( Site 0002)
New York, New York, 10022
Study Coordinator, 212-639-2000
- Recruiting
Mays Cancer Center ( Site 0039)
San Antonio, Texas, 78229
Study Coordinator, 210-450-1000
- Recruiting
TRIALS 365 ( Site 0022)
Shreveport, Louisiana, 71103
Study Coordinator, 318-408-1198
United Kingdom8 sites, 8 recruiting
- Recruiting
Queen Elizabeth Hospital ( Site 2305)
Birmingham, B15 2GW
Study Coordinator, +4401213718771
- Recruiting
University Hospitals Sussex NHS Foundation Trust ( Site 2301)
East Sussex, Brighton And Hove, BN2 1ES
Study Coordinator, 01273 696955
- Recruiting
Western General Hospital ( Site 2307)
Edinburgh, Midlothian, EH4 2XU
Study Coordinator, +441315371859
- Recruiting
St Bartholomew's Hospital ( Site 2302)
London, London, City of, EC1A 7BE
Study Coordinator, +4402044656670
- Recruiting
University College Hospital London ( Site 2303)
London, London, City of, NW1 2PG
Study Coordinator, 020 3456 7890
- Recruiting
Guy's & St Thomas' NHS Foundation Trust ( Site 2309)
London, London, City of, SE1 9RT
Study Coordinator, +4402071881474
- Recruiting
The Christie NHS Foundation Trust ( Site 2300)
Manchester, M20 4BX
Study Coordinator, 01614463746
- Recruiting
The Royal Cornwall Hospital ( Site 2306)
Truro, Cornwall, TR1 3LJ
Study Coordinator, 01872 256424
Brazil6 sites, 6 recruiting
- Recruiting
Hospital Felicio Rocho ( Site 3105)
Belo Horizonte, Minas Gerais, 30110-934
Study Coordinator, +5531986622882
- Recruiting
Liga Norte Riograndense Contra o Cancer ( Site 3108)
Natal, Rio Grande do Norte, 59062-000
Study Coordinator, +5584991425228
- Recruiting
Hospital de Cancer de Pernambuco ( Site 3103)
Recife, Pernambuco, 50040-000
Study Coordinator, +558132178084
- Recruiting
Instituto Nacional de Câncer - INCA ( Site 3107)
Rio de Janeiro, 20230-130
Study Coordinator, +552132072964
- Recruiting
Obras Sociais Irma Dulce ( Site 3112)
Salvador, Estado de Bahia, 41680-430
Study Coordinator, +557134836649
- Recruiting
Hospital Santa Rita de Cassia ( Site 3104)
Vitória, Espírito Santo, 29043-260
Study Coordinator, +55 027 99846-9004
Canada5 sites, 5 recruiting
- Recruiting
Centre Hospitalier de l Universite de Montreal - CHUM ( Site 0200)
Montreal, Quebec, H2X 0C1
Study Coordinator, 514-890-8000
- Recruiting
Jewish General Hospital ( Site 0201)
Montreal, Quebec, H3T 1E2
Study Coordinator, 514-340-8222
- Recruiting
Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre Hospitalier Univer ( Site 0205)
Sherbrooke, Quebec, J1H 5N4
Study Coordinator, 819 346-1110
- Recruiting
Sunnybrook Research Institute ( Site 0203)
Toronto, Ontario, M4N 3M5
Study Coordinator, 4164807802
- Recruiting
Princess Margaret Cancer Centre ( Site 0202)
Toronto, Ontario, M5G 2M9
Study Coordinator, 4169462000
Spain5 sites, 5 recruiting
- Recruiting
CHUAC-Complejo Hospitalario Universitario A Coruña ( Site 2003)
A Coruña, La Coruna, 15006
Study Coordinator, 34981178353
- Recruiting
Institut Català d'Oncologia - L'Hospitalet-Medical Oncology ( Site 2000)
L'Hospitalet de Llobregat, Barcelona, 08908
Study Coordinator, 34932607744
- Recruiting
Clinica Universitaria Navarra - Madrid ( Site 2004)
Madrid, Madrid, Comunidad de, 28027
Study Coordinator, 34913531920/7513
- Recruiting
Hospital Universitario Ramón y Cajal-Medical Oncology ( Site 2002)
Madrid, Madrid, Comunidad de, 28034
Study Coordinator, 34913368263
- Recruiting
HOSPITAL UNIVERSITARIO QUIRONSALUD MADRID-ONCOLOGIA MEDICA ( Site 2001)
Madrid, 28223
Study Coordinator, +34 609378523
Turkey (Türkiye)5 sites, 5 recruiting
- Recruiting
Baskent Universitesi Adana Dr. Turgut Noyan Uygulama ve Arastirma Merkezi ( Site 2201)
Adana, 01240
Study Coordinator, +905446726040
- Recruiting
Hacettepe Universitesi ( Site 2200)
Ankara, 06230
Study Coordinator, +903122976000
- Recruiting
Trakya Üniversitesi Eğitim Araştırma Hastanesi ( Site 2204)
Edirne, 22030
Study Coordinator, +902842360909
- Recruiting
Istanbul Universitesi Cerrahpasa ( Site 2203)
Istanbul, 34098
Study Coordinator, 0090 212 414 30 00
- Recruiting
Koc University, School of Medicine ( Site 2202)
Istanbul, 34450
Study Coordinator, 0090 850 250 82 50
Chile4 sites, 4 recruiting
- Recruiting
Fundación Arturo López Pérez ( Site 3300)
Santiago, Region M. de Santiago, 7500921
Study Coordinator, +56227067543
- Recruiting
Pontificia Universidad Catolica de Chile ( Site 3307)
Santiago, Region M. de Santiago, 8330032
Study Coordinator, +56994945927
- Recruiting
Bradfordhill ( Site 3301)
Santiago, Region M. de Santiago, 8420383
Study Coordinator, 56229490970
- Recruiting
ONCOCENTRO APYS ( Site 3302)
Viña del Mar, Valparaiso, 2520598
Study Coordinator, +56992369820
Peru4 sites, 4 recruiting
- Recruiting
Instituto Regional de Enfermedades Neoplasicas del Centro (IREN CENTRO) ( Site 3405)
Concepción, Departamento de Junín, 12125
Study Coordinator, +51983582526
- Recruiting
IPOR Instituto Peruano de Oncología & Radioterapia ( Site 3400)
Lima, 15036
Study Coordinator, +012241598
- Recruiting
Instituto Nacional de Enfermedades Neoplásicas ( Site 3401)
Lima, 15038
Study Coordinator, +5112016500
- Recruiting
Clínica San Antonio ( Site 3404)
Trujillo, La Libertad, 13008
Study Coordinator, +5144716018
Argentina3 sites, 3 recruiting
- Recruiting
Centro Medico Dr. Doreski - Fundación Respirar ( Site 0302)
Buenos Aires, Buenos Aires F.D., C1118AAT
Study Coordinator, +541147815331
- Recruiting
Instituto Alexander Fleming ( Site 0303)
Buenos Aires, Buenos Aires F.D., C1426ANZ
Study Coordinator, +541132218900
- Recruiting
Hospital Aleman ( Site 0301)
Ciudad Autonoma de Buenos Aires, Buenos Aires, C1118AAT
Study Coordinator, +5491148277000
Malaysia3 sites, 3 recruiting
- Recruiting
Pantai Hospital Kuala Lumpur ( Site 0603)
Kuala Lumpur, 59100
Study Coordinator, +60322960888
- Recruiting
University Malaya Medical Centre ( Site 0601)
Kuala Lumpur, 59100
Study Coordinator, +60379492495
- Recruiting
Sarawak General Hospital ( Site 0602)
Kuching, Sarawak, 93586
Study Coordinator, +6082276666
Taiwan3 sites, 3 recruiting
- Recruiting
Taichung Veterans General Hospital ( Site 1004)
Taichung, 407
Study Coordinator, 886423592525x5822
- Recruiting
National Cheng Kung University Hospital ( Site 1003)
Tainan, 704
Study Coordinator, 88662353535x6729
- Recruiting
Mackay Memorial Hospital ( Site 1002)
Taipei, 10449
Study Coordinator, +886225433535x3941
Thailand3 sites, 3 recruiting
- Recruiting
Faculty of Medicine Siriraj Hospital ( Site 1111)
Bangkok, Bangkok, 10700
Study Coordinator, +6624141895
- Recruiting
Chulalongkorn Hospital ( Site 1114)
Pathumwan, Bangkok, 10330
Study Coordinator, +6622516704
- Recruiting
Songklanagarind Hospital ( Site 1113)
Songkhla, 90110
Study Coordinator, +6674451469
Singapore1 site, 1 recruiting
- Recruiting
National Cancer Centre Singapore ( Site 0800)
Singapore, Central Singapore, 168583
Study Coordinator, +6564368000
About this study
Official title: A Multicenter, Open-label, Phase 2 Basket Study of MK-5684 in Participants With Selected Solid Tumors (OMAHA-015)
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.
- Conditions
- Malignant Neoplasm
- Being tested
- Opevesostat, Fludrocortisone/ Fludrocortisone acetate, Dexamethasone/Dexamethasone acetate, Rescue Medications, Fulvestrant
- Medical subject headings
- Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OpevesostatDrug
Also called MK-5684
Tablet for oral administration.
Fludrocortisone/ Fludrocortisone acetateDrug
Tablet for oral administration.
Dexamethasone/Dexamethasone acetateDrug
Tablet for oral administration.
Rescue MedicationsDrug
Hydrocortisone or hydrocortisone/hydrocortisone acetate administered via intramuscular injection as rescue medication.
FulvestrantDrug
Administered via intramuscular injection.
ExemestaneDrug
Tablet for oral administration.
Megestrol acetate/Medroxyprogesterone acetateDrug
Tablet for oral administration.
TamoxifenDrug
Tablet for oral administration.
LetrozoleDrug
Tablet for oral administration.
| Study group | Role | What they receive |
|---|---|---|
| MK-5684 and Daily Corticosteroids | Experimental | 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. Receives: Drug: Opevesostat; Drug: Fludrocortisone/ Fludrocortisone acetate; Drug: Dexamethasone/Dexamethasone acetate; Drug: Rescue Medications |
| Fulvestrant or Exemestane | Experimental | 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. Receives: Drug: Fulvestrant; Drug: Exemestane |
| Observation (No Treatment) | No intervention | Participants with ovarian cancer will be observed but will receive no treatment for the duration of the study. |
| Treatment of Physician's Choice | Experimental | 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. Receives: Drug: Megestrol acetate/Medroxyprogesterone acetate; Drug: Tamoxifen; Drug: Letrozole |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression-Free Survival (PFS) - All Cohorts
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.
Measured: Up to approximately 2 years
Secondary outcomes (6)
Overall Survival (OS) - All Cohorts
For all cohorts, OS is defined the time from randomization to death due to any cause.
Measured: Up to approximately 2 years
Clinical Benefit Rate (CBR) - Cohort A
For cohort A (participants with breast cancer), CBR is defined as the percentage of participants who have complete response (CR): disappearance of all target lesions; partial response (PR): At least a 30% decrease in the sum of diameters of target lesions; or stable disease (SD): Neither sufficient decrease to qualify for PR nor sufficient increase to qualify for progressive disease (PD), with reference to the smallest sum diameters while on study) for ≥24 weeks per RECIST 1.1 as assessed by BICR.
Measured: Up to approximately 2 years
Objective Response Rate (ORR) - All Cohorts
For all cohorts, ORR is defined as the percentage of participants who have achieved confirmed Complete Response (CR: disappearance of all target lesions) or a Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 as assessed by BICR.
Measured: Up to approximately 2 years
Duration of Response (DOR) - All Cohorts
For all cohorts, for participants who demonstrate CR or PR, DOR is defined as the time from the first documented evidence of CR or PR until disease progression or death due to any cause, whichever occurs first.
Measured: Up to approximately 2 years
Number of Participants who Discontinue Study Intervention Due to an Adverse Event (AE) - All Cohorts
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Measured: Up to approximately 8 months
Number of Participants who Experience One or More Adverse Events (AEs) - All Cohorts
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Measured: Up to approximately 11 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 May 2025
- Study start11 Aug 2025
- Primary completion4 Nov 2027 (estimated)
- Study completion4 Nov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Malignant NeoplasmStudies of the same condition, open and under way.
- More trials run by Merck Sharp & Dohme LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 250 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Merck Sharp & Dohme LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06979596
- Sponsor's protocol ID
- 5684-015
- Other IDs
- 2024-519563-18-00, U1111-1315-5430, MK-5684-015, OMAHA-015
- Status last verified
- Oct 2026
- First submitted
- 13 May 2025
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Open-label, Phase 2 Basket Study of MK-5684 in Participants With Selected Solid Tumors (OMAHA-015)
- ClinicalTrials.gov ID
- NCT06979596
- Acronym / sponsor ID
- 5684-015
- Conditions
- Malignant Neoplasm
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 250 participants (estimated)
- Lead sponsor
- Merck Sharp & Dohme LLCIndustry (pharma, biotech, devices)
- Study start
- 11 Aug 2025 (actual)
- Primary completion
- 4 Nov 2027 (estimated)
- Study completion
- 4 Nov 2027 (estimated)
- First posted
- 20 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| MK-5684 and Daily Corticosteroids | Experimental | Drug: Opevesostat, Drug: Fludrocortisone/ Fludrocortisone acetate, Drug: Dexamethasone/Dexamethasone acetate, Drug: Rescue MedicationsParticipants 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. |
| Fulvestrant or Exemestane | Experimental | Drug: Fulvestrant, Drug: ExemestaneParticipants 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. |
| Observation (No Treatment) | No intervention | –Participants with ovarian cancer will be observed but will receive no treatment for the duration of the study. |
| Treatment of Physician's Choice | Experimental | Drug: Megestrol acetate/Medroxyprogesterone acetate, Drug: Tamoxifen, Drug: LetrozoleParticipants 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (15 listed)
- Cohort A:
- Cohort B:
- Cohort C:
- All Cohorts :
Key exclusion criteria (21 listed)
- Cohort A:
- Cohort B:
- Cohort C:
- All Cohorts:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OpevesostatAlso: MK-5684Tablet for oral administration. | Drug | MK-5684 and Daily Corticosteroids |
| Fludrocortisone/ Fludrocortisone acetateTablet for oral administration. | Drug | MK-5684 and Daily Corticosteroids |
| Dexamethasone/Dexamethasone acetateTablet for oral administration. | Drug | MK-5684 and Daily Corticosteroids |
| Rescue MedicationsHydrocortisone or hydrocortisone/hydrocortisone acetate administered via intramuscular injection as rescue medication. | Drug | MK-5684 and Daily Corticosteroids |
| FulvestrantAdministered via intramuscular injection. | Drug | Fulvestrant or Exemestane |
| ExemestaneTablet for oral administration. | Drug | Fulvestrant or Exemestane |
| Megestrol acetate/Medroxyprogesterone acetateTablet for oral administration. | Drug | Treatment of Physician's Choice |
| TamoxifenTablet for oral administration. | Drug | Treatment of Physician's Choice |
| LetrozoleTablet for oral administration. | Drug | Treatment of Physician's Choice |
Primary outcome
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.
6 secondary outcomes
Overall Survival (OS) - All Cohorts
Time frame: Up to approximately 2 years
Clinical Benefit Rate (CBR) - Cohort A
Time frame: Up to approximately 2 years
Objective Response Rate (ORR) - All Cohorts
Time frame: Up to approximately 2 years
Duration of Response (DOR) - All Cohorts
Time frame: Up to approximately 2 years
Number of Participants who Discontinue Study Intervention Due to an Adverse Event (AE) - All Cohorts
Time frame: Up to approximately 8 months
Number of Participants who Experience One or More Adverse Events (AEs) - All Cohorts
Time frame: Up to approximately 11 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Oct 2026.
- Merck Clinical Trials InformationLink provided by the sponsor.
- Plain Language SummaryLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Related trials for Malignant Neoplasm
Not yet recruitingPhase 1
Hepatic Artery Infusion of Carfilzomib in Participants With Liver Metastatic Disease Previously Treated With Hepatic Artery Infusion Pump Therapy
Colorectal Neoplasms, Neoplasms
RecruitingPhase 2
Engaging T-cells to Eliminate MRD in Newly Diagnosed Myeloma Optimizing Response With Talquetmab and Teclistamab (ROTATE)
Multiple Myeloma
Not yet recruiting
Augmented-Reality ICG Fluorescence Second-Look for Residual Nodal Disease After Axillary Dissection in Breast Cancer
Breast Cancer, Breast Neoplasms
RecruitingPhase 2
Testing New Therapies for Patients With Acute Myeloid Leukemia Who Are Newly Diagnosed and Have Not Yet Started Treatment (A MyeloMATCH Treatment Trial)
Acute Myeloid Leukemia, Acute Myeloid Leukemia Arising From Previous Myelodysplastic/Myeloproliferative Neoplasm
RecruitingPhase 3
Somatostatin Analogues vs. Observation After Peptide Receptor Radionuclide Therapy (PRRT) in Nonfunctional Neuroendocrine Neoplasms
Neuroendocrine Neoplasm, Gastroenteropancreatic Neuroendocrine Neoplasm
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director study director
Merck Sharp & Dohme LLC
60 sites in 13 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Opevesostat, Fludrocortisone/ Fludrocortisone acetate and Dexamethasone/Dexamethasone acetate in people with Malignant Neoplasm, run by Merck Sharp & Dohme LLC at 60 sites in 13 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 15 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 60 sites in United States, United Kingdom, Brazil, Canada, Spain and 8 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Toll Free Number (1-888-577-8839, Trialsites@msd.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Progression-Free Survival (PFS) - All Cohorts (time frame: Up to approximately 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Oct 2026.