*MK-5684 in Participants With Selected Solid Tumours

• Research type

  Research Study

• Full title

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

• IRAS ID

  1011696

• Contact name

  - -

• Contact email

  N/A

• Sponsor organisation

  Merck Sharp & Dohme LLC

• Research summary

  Researchers are looking for new ways to treat certain solid tumours (breast cancer [BC], ovarian cancer [OC] and endometrial cancer [EC]) that need steroid hormones to grow or spread.

  The standard treatments for these cancers may not work for some people and may stop working to treat the cancer over time.

  Researchers want to learn if the trial medicine, opevesostat (also called MK-5684), can treat BC, OC, and EC. Opevesostat is designed to treat cancer by blocking the body from making steroid hormones.

  The goal is to learn if people who receive opevesostat live longer without the cancer growing or spreading compared to people who receive standard treatment.

  About 250 people will be in this trial. They must meet certain criteria, including if they:
  • Are 18 years or older
  • Have:
  o BC that was previously treated and cannot be removed with surgery
  o OC that was previously treated
  o A specific type of EC and may have been previously treated
  • Do not have cancer that has spread to the adrenal glands
  • Do not have other certain adrenal gland conditions

  People will be placed in a group based on the type of cancer they have:
  • Group A (BC) – Opevesostat with supportive adrenal therapy (SAT) or endocrine therapy (fulvestrant or exemestane)
  • Group B (OC) – Opevesostat with SAT or observation to see if the cancer grows or spreads without further treatment
  • Group C (EC) – Opevesostat with SAT or standard hormonal treatment (megestrol acetate, switching every 3 weeks between megestrol acetate and tamoxifen or letrozole)

  People will receive treatment for about 8 months or until the cancer gets worse or the treatments are not tolerated.

  People may give blood, urine, and tumour samples, have imaging tests, physical examinations, and ECGs. People may be in the trial for about 3 years.

• REC name

  London - London Bridge Research Ethics Committee

• REC reference

  25/LO/0348

• Date of REC Opinion

  5 Aug 2025

• REC opinion

  Further Information Favourable Opinion