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MK-5684 for breast, ovarian, and endometrial cancer

A Multicenter, Open-label, Phase 2 Basket Study of MK-5684 in Participants With Selected Solid Tumors (OMAHA-015)

Phase 2 Interventional Merck Sharp & Dohme LLC · NCT06979596

This trial will test whether MK-5684 helps people with certain breast, ovarian, or endometrial cancers live longer without the disease growing or spreading.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment250 (estimated)
Ages18 Years and up
SexAll
SponsorMerck Sharp & Dohme LLC Industry-sponsored
Drugs / interventionschemotherapy
Locations55 sites (Anchorage, Alaska and 54 other locations)
Trial IDNCT06979596 on ClinicalTrials.gov

What this trial studies

MK-5684 is an experimental drug designed to block the body's production of steroid hormones that can fuel some cancers. In this Phase 2 study, people with hormone receptor–positive metastatic or unresectable breast cancer and people with high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer are assigned to receive MK-5684 or a standard treatment for their cancer type and monitored for tumor growth and survival. The primary goal is to determine whether MK-5684 prolongs progression-free survival compared with standard therapy. Supportive medications such as fludrocortisone, dexamethasone, and fulvestrant may be given per protocol as needed.

Who should consider this trial

Good fit: Ideal participants are adults with HR+/HER2‑ metastatic or unresectable breast cancer after prior endocrine therapy, or adults with high‑grade epithelial ovarian, fallopian tube, or primary peritoneal carcinoma who meet the trial's other medical criteria.

Not a fit: Patients with tumors not driven by steroid hormones, early-stage disease that can be cured by surgery, or those unable to tolerate steroid-suppression medications are unlikely to benefit.

Why it matters

Potential benefit: If successful, MK-5684 could extend the time patients live without their cancer getting worse compared with current standard treatments.

How similar studies have performed: Other drugs that block steroid hormone synthesis have shown benefit in some hormone-driven cancers, but MK-5684 is a newer agent with limited prior clinical data.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

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.
  * 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:

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.
  * 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.

Where this trial is running

Anchorage, Alaska and 54 other locations

+5 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
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Conditions Malignant Neoplasm
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.