ClinicalTrials.gov record NCT07138274

Metyrapone Study for Patients Diagnosed With Mild Autonomous Cortisol Secretion - MACS

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 17, 2026

A Phase II, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Safety and Efficacy of Metyrapone in Subjects Diagnosed With Mild Autonomous Cortisol Secretion (MACS)

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 2A study that tests whether a treatment has the intended effect and continues to check safety, usually in a larger group than phase 1.
Age18 years old and older
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Phase II, randomized, double-blind, placebo-controlled trial testing oral metyrapone in people diagnosed with MACS. Participants are randomized 2:1 to metyrapone or matching placebo for a 6-month main study, with remote screening and consent. After 6 months, there are options for an open-label treatment arm or an observational arm through month 12.

What it is studying. The study is testing the safety and biological effects of metyrapone in people with MACS. It measures changes in steroid metabolism (including a glucocorticoid-to-androgen ratio and waking/bedtime salivary cortisone) and tracks clinical measures such as adrenal function markers, body mass index, blood sugar, blood pressure, and quality of life.

What the researchers hope to learn. To evaluate metyrapone's safety and its effects on steroid metabolism in people with MACS. To measure biochemical changes (glucocorticoid-to-androgen ratio, salivary cortisone) and collect data on adrenal insufficiency markers, adverse events, BMI, blood sugar, blood pressure, and quality of life over 3 and 6 months.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

single-center, randomized, double-blind, placebo-controlled Phase 2 study to evaluate safety and efficacy of overnight metyrapone in patients with MACS.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • Metyrapone 250 mg Oral Tablets
  • Placebo

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Provide written informed consent.
  • Stated willingness to comply with all study procedures and availability for the duration of the study.
  • Age ≥ 18 years
  • Diagnosed with MACS i. at least 2 abnormal post-dexamethasone cortisol results1 mg post-dexamethasone cortisol >1.8 mcg/dL or ii. 8 mg post-dexamethasone cortisol >1 mcg/dL b. Historical dexamethasone suppression test results can be used if performed within 24 months prior to enrollment.
  • Adrenal imaging phenotype consistent with benign disease (adrenal adenoma/s, macronodular or micronodular adrenal hyperplasia)
  • At least one of the following comorbidities:
  • obesity (BMI>30 kg/m2)
  • dysglycemia
  • dyslipidemia
  • hypertension
  • osteopenia
  • osteoporosis
  • fragility fractures
  • Ability to take oral medication and be willing to adhere to the study intervention regimen.
  • For persons of childbearing potential: : agreement to remain abstinent (refrain from heterosexual intercourse) or use a contraceptive method with a failure rate of ≤ 5% per year during the treatment period and for 1 month after the last dose of study treatment.
  • Stable timing for bedtime for at least one week prior to on-site study visits.
  • History of difficulty providing blood via standard blood draw methods

Exclusion criteria

  • Planned alternative therapy for MACS within 12 months after joining the study.
  • Current use of oral exogenous glucocorticoid therapy
  • Current use of opioid therapy >20 MME/day
  • Planned use of oral exogenous glucocorticoid therapy
  • Planned use of opioid therapy >20 MME/day
  • Use of injectable glucocorticoid within 6 weeks prior to Day 1
  • Investigator's judgement based on history/physical examination that a comorbidity or concomitant medication may impact the hypothalamic-pituitary-adrenal axis or steroid metabolome
  • Uncontrolled intercurrent illness including, but not limited to:
  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia
  • Psychiatric illness/social situations that would limit compliance with study requirements
  • Pregnancy or lactation
  • Known allergic reactions to metyrapone
  • Suspected false positive post-dexamethasone cortisol results due to increased metabolism, poor absorption, or noncompliance with dexamethasone
  • Treatment with another investigational drug or other intervention within lower than specific therapy washout period

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

This study is a double blind, placebo-controlled phase II trial of the safety and efficacy of Metyrapone, in the treatment of MACS. Subjects will be remotely screened and interested qualified subjects will be remotely consented. Subjects will be randomized 2:1 for 6 months of the main study. At 6 months, two options will be available for subjects for months 6-12: open-label arm, observational arm.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants will be remotely screened and consented, then randomized 2:1 to oral metyrapone (titrated from 500 mg up to 1000 mg) or matching placebo for 6 months; after 6 months they may enter an open‑label arm or an observational arm. Study activities include blood draws, urine 25‑steroid profiling, waking and bedtime salivary cortisone samples, morning ACTH and cortisol tests, weight/BMI checks, and questionnaires (AddiQoL and SF‑36); adverse events will be monitored continuously. The AddiQoL survey is given at baseline, one week after each dose titration, and at 3 and 6 months. The registry does not list exact visit counts or every test that will be done.

How the study is structured. Randomized (2:1), double-blind, placebo-controlled drug trial. Participants take oral metyrapone (starting around 500 mg and titrated up to 1000 mg) or matching placebo for the 6-month main study. Key measurements occur at baseline, 3 months, and 6 months and include urine steroid profiling, salivary cortisone, morning ACTH/cortisol, questionnaires (AddiQoL, SF-36), and safety monitoring. After month 6, participants may enter an open-label treatment arm or an observational follow-up through month 12.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The registry lists this study under Mild Autonomous Cortisol Secretion (MACS); Autonomous Cortisol Secretion (ACS). Does it apply to my diagnosis?
  • Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on congenital adrenal hyperplasia

Clinical trials43 trials listed for congenital adrenal hyperplasiaEvery trial the registry lists for congenital adrenal hyperplasia, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in congenital adrenal hyperplasia researchLatest monthly update: September 2026. Includes: Bedtime hydrocortisone. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
October 2026 (estimated)
Primary completion
June 2031 (estimated)
Study completion
December 2031 (estimated)
Target enrollment
90 participants (estimated)
Last updated on registry
Sep 25, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Mayo Clinic
Principal investigator
Irina Bancos, Principal Investigator
Mayo Clinic

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

Terms used on this page · explanations by MedicalUpdates.ai

randomized
Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
double-blind
Two types of people involved in the study do not know which intervention a participant is receiving. The ClinicalTrials.gov record specifies who is masked, for example participants, care providers, investigators or outcome assessors.
placebo-controlled
A study design in which one group receives a placebo so that the study treatment's effects can be compared with no active treatment.
written informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
childbearing potential
Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
glucocorticoid
Steroid medicines, such as prednisone, that reduce inflammation. Studies often require a stable dose at entry or measure whether the study treatment allows the dose to be reduced.
concomitant medication
Other medicines a participant takes during the study. Some must be reported; some are restricted.
investigational drug
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
washout period
A period during which a participant stops a previous treatment before starting the study treatment, so the earlier treatment does not affect the results.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
2:1
How many participants go to each group. In a 2:1 ratio, two are assigned to the first group for every one assigned to the second.
open-label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
observational
A study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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