A Phase 3 interventional study of Atumelnant and Placebo in Congenital Adrenal Hyperplasia and Classic Congenital Adrenal Hyperplasia, sponsored by Crinetics Pharmaceuticals Inc.. Recruiting at 82 sites in 15 countries. Open to participants aged 18 Years to 74 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Crinetics Pharmaceuticals Inc. (part of Vertex Pharmaceuticals Incorporated) · Phase 3, Interventional, and Treatment
The purpose of this study is to evaluate the efficacy, safety, PK, and PD of atumelnant in adults with classic CAH due to 21-OHD.
This is a Phase 3, global, multicenter, randomized, double-blind, placebo-controlled study in adult participants (male or female age ≥18 to \<75 years) with classic CAH due to 21-OHD who have been on a stable regimen of GCs for at least 2 months to evaluate efficacy, safety, PK, and PD of atumelnant administered once per day. Following a 3- to 6-week Screening Period, eligible participants will enter the Treatment Period where they will be randomly assigned in a 2:1 ratio to receive either atumelnant 80 mg once daily (with an option for dose escalation to 120 mg once daily at Week 20) or placebo.
A total of approximately 150 participants may be enrolled in the study.
101 studies on the registry are indexed under Adrenal Hyperplasia, Congenital; 28 are open to participants now.
This study's planned enrollment of 150 is above the median of 37 across 50 interventional studies indexed under Adrenal Hyperplasia, Congenital.
Browse Adrenal Hyperplasia, Congenital studies →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.
Counted across the registry records on this site, refreshed daily.
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.
Participants with Visit 2 levels of morning serum A4 as follows:
Exclusion Criteria:
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.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Atumelnant tablet, administered orally, once daily for 32 weeks.
Drug: Atumelnant
Matching placebo, administered orally, once daily for 32 weeks.
Drug: Placebo
Atumelnant, tablets, once daily by mouth
Also known as: CRN04894
Placebo, tablets, once daily by mouth
Proportion of participants with morning post-GC A4 ≤ ULN who are on physiologic GC replacement.
Time frame: Week 32
Percent change from baseline of morning pre-GC A4
Time frame: Week 2
Percent change from baseline of morning pre-GC 17-OHP
Time frame: Week 32
Proportion of participants with morning pre-GC A4 ≤ ULN who are on physiologic GC replacement
Time frame: Week 32
Percent change from baseline in GC daily dose when morning post-GC A4 ≤ ULN
Time frame: Week 32
Plan to share: No
No publications or documents are linked to this record.
Started Dec 2025 (actual). Primary completion is estimated for May 2027, 17 months after the start.
How these figures are worked out, and which studies are left out of them.
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 ↗
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Studies of the drug tested here: Atumelnant
Adrenal Hyperplasia, Congenital →
Crinetics Pharmaceuticals Inc. →