Metyrapone for Mild Autonomous Cortisol Secretion (MACS)

September 16, 2025 updated by: Irina Bancos, Mayo Clinic

Metyrapone Intervention in Patients With Mild Autonomous Cortisol Secretion (MACS)

The purpose of this study is to find out whether the study drug, metyrapone, is safe and effective in treating participants with Mild Autonomous Cortisol Secretion (MACS).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study will look at how well metyrapone controls blood pressure, blood glucose, blood lipids and weight.

Metyrapone is approved in the United States of America (USA) by the Federal Drug Administration (FDA) for use in the diagnosis of adrenal insufficiency. It is not approved in the USA for the treatment of MACS. It is approved in Europe for the treatment of ACTH dependent Cushing's Syndrome.

Metyrapone is currently being tested to evaluate the safety (side effects/risks) and efficacy (benefits), so its use for the treatment of MACS is experimental in the USA. Its effectiveness is unproven in the USA and metyrapone is considered an investigational study drug in the USA. The Mayo Clinic IRB has given approval for this drug to be used in this setting.

Patients diagnosed with MACS have abnormal cortisol levels above the normal range. Cortisol acts by binding with the cortisol receptors in many tissues of the body. Metyrapone works by reducing cortisol production, thereby decreasing the effects of too much cortisol. Metyrapone doesn't affect levels of other hormones in your body.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic Minnesota

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Provide written informed consent.
  • Stated willingness to comply with all study procedures and availability for the duration of the study.
  • Diagnosed with MACS: at least 2 abnormal post-dexamethasone cortisol results (1 mg post-dexamethasone cortisol > 1.8 mcg/d; or 8 mg post-dexamethasone cortisol > 1 mcg/dL) and 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/m^2); dysglycemia; dyslipidemia; hypertension; osteopenia; osteoporosis; fragility fractures.
  • Ability to take oral medication and be willing to adhere to the study intervention regimen.
  • For females of reproductive potential: use of highly effective contraception initiated prior to baseline visit and for 1 month after completing metyrapone study.
  • 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 6 months after the last dose of study treatment.
  • Stable timing for bedtime for at least one week prior to on-site study visits

Exclusion Criteria:

  • Planned alternative therapy for MACS within 6 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 the last 6 weeks.
  • 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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Mild Autonomous Cortisol Secretion (MACS) Open Label Phase and Optional Extension Phase
Subjects diagnosed with Mild Autonomous Cortisol Secretion (MACS) will receive metyrapone for a 6 month treatment period (Open Label Phase) with the option to continue for an additional 30 months of metyrapone therapy. If a patient chooses to participate in the Optional Extension Phase they will continue to receive metyrapone therapy until Month 36. This is an additional 30 months of therapy after completion of the Open Label Phase.
Drug: Metyrapone
250 to 1000 milligram (mg) orally in one or two doses in the evening (administered 4 and 2 hours prior to bed)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Adverse Events
Time Frame: 50 months
Number of participants to experience adverse events
50 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Irina Bancos, MD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 19, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 24, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 24, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 30, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 22, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 23-008085

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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