A Study in Pediatric Participants With Congenital Adrenal Hyperplasia (Balance-CAH)

Not Applicable

Not yet recruiting

• Conditions: Congenital Adrenal Hyperplasia; Classic Congenital Adrenal Hyperplasia
• Interventions: Drug: Atumelnant; Drug: Placebo

• Registration Number: NCT07159841
• Lead Sponsor: Crinetics Pharmaceuticals Inc.

Brief Summary

The purpose of this study is to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of atumelnant treatment in pediatric participants with classic congenital adrenal hyperplasia (CAH).

Detailed Description

This Phase 2/3 plus open-label extension study is designed to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of atumelnant treatment in pediatric participants with classic CAH. Part A is a Phase 2, open-label, semi-sequential cohorts portion of the study. Part B is the Phase 3, double-blind, randomized, placebo controlled confirmatory portion of the study. Part C is the open-label extension (OLE) portion of the study. Participants in Part A and B are eligible to enroll in Part C (OLE).

A total of approximately 153 participants may be enrolled in the study (planned and optional cohorts) ages 1 to \< 18 years old.

The first 3 cohorts in Part A are for ages 12 to \<18 years and will be sequential, and Safety Review Committee (SRC) review of data and approval to proceed is required prior to enrolling each subsequent cohort. The fourth cohort in Part A is for ages 1 to 11 years old and will begin after Cohorts 1 and 2 have been completed, additional requirements are fulfilled, and following SRC review of Cohorts 1 and 2 data.

Study Timeline

• Status Verified: 2025-08
• Study First Submitted: 2025-08-29
• Study First Submitted QC: 2025-08-29
• Last Update Submitted: 2025-08-29
• Study Start: 2025-09-01
• Study First Posted: 2025-09-08
• Last Update Posted: 2025-09-08
• Primary Completion: 2030-03
• Study Completion: 2030-03-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 153

Inclusion Criteria

Part A and B participants are eligible to be included in the study only if all of the following criteria apply:

1. Male or female at birth, between 1 to <18 years of chronological age at the time of signing the Informed Consent Form (ICF).
2. Have a medically confirmed diagnosis of classic CAH due to 21-hydroxylase deficiency (21-OHD) based on standard medically accepted criteria such as elevated 17-OHP level, confirmed CYP21A2 genetic testing, positive newborn screening with confirmatory second tier testing, or cosyntropin stimulation.
3. Participants must have an elevated morning serum A4 level >ULN during Screening obtained prior to morning glucocorticoid (GC) administration.
4. Participants must be on a stable supraphysiologic GC replacement therapy for at least one month prior to Screening.
5. Compliance, as judged per Investigator discretion, with GC replacement and mineralocorticoid replacement (if applicable) regimen documented during the Screening Period.
6. Normal thyroid stimulating hormone (TSH) and thyroxine (T4) within 3 months of Screening per age-appropriate range.

Part C inclusion criteria require participants to complete treatment in either Part A or Part B and in the Investigator's opinion it would benefit the participant to continue in Part C, regardless of age.

Exclusion Criteria

Part A and Part B: Individuals in Part A and Part B who meet any of the following criteria will be excluded from participation in this study:

1. Diagnosis of any form of CAH other than classic 21-OHD.

2. Participants treated with other GCs within 30 days of Screening.

3. Stress dose of GC therapy within 2 weeks of start of Screening, defined as any dose above the normal maintenance dose, including but not limited to intravenous (IV) or intramuscular (IM) hydrocortisone.

4. Use of growth hormones within 1 week of start of Screening for short acting, or within 6 weeks of start of Screening for long acting.

5. Use of a corticotropin-releasing factor receptor antagonist within 14 days of Screening.

6. History of cancer excluding cured/treated dermal squamous or basal cell carcinoma or cervical carcinoma in situ.

7. Abnormal sleep/wake cycles (as determined by the Investigator).

8. Female participants who are pregnant or lactating.

9. Participants who have been dosed with an investigational drug (other than atumelnant) in any prior clinical study within 60 days or 5 half-lives (whichever is longer) prior to the first dose.

   Part C:

10. Individuals in Part C who do not meet the Part C Inclusion Criteria.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SEQUENTIAL

Arm && Interventions

Group	Intervention	Description
Treatment (Part A)	Atumelnant	Open-label, semi-sequential cohorts.
Active Treatment (Part B)	Atumelnant	Randomized, Parallel Arms, Double-Blind
Placebo (Part B)	Placebo	Randomized, Parallel Arms, Double-Blind
Open-Label Treatment (Part C)	Atumelnant	Open-label treatment period for participants entering Part C from Part A and B.

Primary Outcome Measures

Name	Time	Method
Change from baseline in morning serum androstenedione (A4) (Part A)	Week 8
Percent change from baseline in glucocorticoid (GC) daily dose while serum early morning A4 ≤Upper Limit of Normal (ULN) (Part B)	Week 28
Change from baseline in serum early morning A4 over time (Part C)	Up to Week 260

Secondary Outcome Measures

Name	Time	Method
Change from baseline in morning serum 17-hydroxyprogesterone (17-OHP) (Part A)	Week 8
Plasma and/or blood concentrations of atumelnant (Part A)	Up to Week 8
Change from baseline in serum early morning A4 (Part B)	Week 4
Change from baseline in serum early morning 17-OHP (Part B)	Week 4
Proportion of participants with physiologic GC dose while serum early morning A4 <ULN (Part B)	Week 28
Change from baseline in serum early morning 17-OHP over time (Part C)	Up to Week 260
Percent change from baseline in GC daily dose over time (Part C)	Up to Week 260
Proportion of participants with physiologic GC dose while serum early morning A4 <ULN over time (Part C)	Up to Week 260