ClinicalTrials.gg
Sign In
CompletedNCT05804669Updated Oct 14, 2026

A Study to Evaluate the Safety and PK of CRN04894 for the Treatment of Cushing's Syndrome

A Phase 1/2 interventional study of atumelnant in Cushing Syndrome, Cushing Disease and Ectopic ACTH Syndrome, sponsored by Crinetics Pharmaceuticals Inc.. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-14.

Sponsored by Crinetics Pharmaceuticals Inc. (part of Vertex Pharmaceuticals Incorporated) · Phase 1/2, Interventional, and Treatment

Updated Oct 14, 2026Now CompletedPrimary completion moved+1 moreGo to Updates ↓
Phase
Phase 1/2
Study type
Interventional
Enrollment
19
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

A Phase 1b/2a, first-in-disease, open-label, multiple-ascending dose exploratory study to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamic biomarker responses associated with CRN04894 (an adrenocorticotropic hormone [ACTH] receptor antagonist) in participants with ACTH-dependent Cushing's syndrome (Cushing's disease or Ectopic ACTH Syndrome [EAS])

Read the detailed description

This is a Phase 1b/2a, first-in-disease, open-label, multiple-ascending dose exploratory study to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamic biomarker responses associated with atumelnant (also known as CRN04894) (an adrenocorticotropic hormone [ACTH] receptor antagonist) over a 10-day or 14-day treatment period in participants with ACTH-dependent Cushing's syndrome (Cushing's disease or Ectopic ACTH Syndrome [EAS]). Participants will receive oral atumelnant once daily for 10 days followed by monitoring during 4 'wash-out' days, or for 14 days.

02

Conditions studied

  • Cushing Syndrome
  • Cushing Disease
  • Ectopic ACTH Syndrome

Keywords

  • Cushing Syndrome
  • Cushing Disease
  • Ectopic ACTH Syndrome
  • CRN04894
  • atumelnant
03

In context

Cushing Syndrome

123 studies on the registry are indexed under Cushing Syndrome; 42 are open to participants now.

This study's enrollment of 19 is below the median of 44 across 58 interventional studies indexed under Cushing Syndrome.

Browse Cushing Syndrome studies →

Lead sponsor

Crinetics Pharmaceuticals Inc. is the lead sponsor of 19 studies on the registry; 3 are open to participants now.

Of its 12 completed or terminated interventional studies of FDA-regulated products, 6 (50%) have results posted.

First submitted before Crinetics Pharmaceuticals Inc. became part of Vertex Pharmaceuticals Incorporated.

Browse Crinetics Pharmaceuticals Inc. studies →All Vertex Pharmaceuticals Incorporated studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Adult male or female, aged 18 years or more
  2. Evidence of chronic 'active' ACTH-dependent Cushing's syndrome
  3. Evidence of acutely 'active' ACTH-dependent Cushing's syndrome within 10 days of Day 1
  4. Participants with documented ACTH-dependent Cushing's syndrome taking short-acting steroidogenesis inhibitors (ketoconazole, levoketoconazole, osilodrostat, or metyrapone) may participate after a of at least 5 days, if they meet other study inclusion criteria, relative to Investigator's judgment. Participants with documented ACTH-dependent Cushing's syndrome taking cabergoline may participate after a washout period of at least 14 days, if they meet other study inclusion criteria

Exclusion criteria

Exclusion Criteria:

  1. Women who are pregnant or lactating
  2. History of bilateral adrenalectomy
  3. Previous pituitary MRI findings of a putative ACTH-secreting lesion within 3 mm of the optic chiasm
  4. Presence of any known
  5. Use of mitotane
  6. Previous unsuccessful surgery for Cushing's syndrome within 6 weeks
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
19 participants (actual)

Study arms

  • Experimental
    Multiple Ascending Doses

    Sequential, open-label, 10-day or 14-day fixed-dose cohorts.

    Drug: atumelnant

Interventions

  • Drugatumelnant

    Atumelnant is an orally active investigational agent which antagonizes the action of ACTH at its receptor administered as oral tablets.

06

What researchers measure

Primary outcomes

  1. Proportion of participants with treatment emergent adverse events (TEAEs)

    Time frame: Up to Day 15

  2. Proportion of participants with adrenal insufficiency

    Time frame: Up to Day 15

  3. Proportion of participants with safety findings determined by laboratory testing

    Time frame: Up to Day 15

  4. Assessment of the maximum observed plasma concentration of CRN04894

    Time frame: Up to Day 15

  5. Assessment of the time to achieve maximum observed plasma concentration of CRN04894

    Time frame: Up to Day 15

  6. Assessment of the plasma area under the curve of CRN04894

    Time frame: Up to Day 15

Secondary outcomes

  1. Change from baseline in early morning serum cortisol

    Time frame: Up to Day 15

07

Study locations

1 site
  • National Institutes of Health (NIH) - National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
    Bethesda, Maryland 20892, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedDate before it movedWhere the date was before it moved

Ran from Oct 2023 to primary completion in Aug 2026, 34 months.

Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 14, 2026: primary completion Oct 2026 → Aug 2026 and completion Oct 2026 → Sep 2026.

Earlier changes are on the record history on ClinicalTrials.gov ↗

How these figures are worked out, and which studies are left out of them.

Registered
Mar 27, 2023
First posted
Apr 7, 2023
StartActual
Oct 12, 2023
Primary completionActual
Aug 25, 2026was Oct 2026
CompletionActual
Sep 8, 2026was Oct 2026
Last update
Oct 14, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Status
Active, not recruiting→Completed
changed Oct 14, 2026
Primary completion
Oct 2026→Aug 25, 2026 (actual)
Oct 14, 2026
Study completion
Oct 2026→Sep 8, 2026 (actual)
Oct 14, 2026
Show all 1 update
  1. Oct 14, 2026
    Active, not recruiting→Completed
    Primary completion Oct 2026→Aug 25, 2026 (now actual)
    Study completion Oct 2026→Sep 8, 2026 (now actual)
    + 1 other change: verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT05804669
Lead sponsor
Crinetics Pharmaceuticals Inc.
Responsible party
Sponsor
First posted
Apr 7, 2023
Start date
Oct 12, 2023
Primary completion
Aug 25, 2026
Completion
Sep 8, 2026
Last update
Oct 14, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Studies of the drug tested here: Atumelnant

Other studies in this condition

Cushing Syndrome →

Other studies from this sponsor

Crinetics Pharmaceuticals Inc. →

Start the discussion