Glucocorticoid Reduction After Starting Crinecerfont in Pediatric Patients With Classic CAH: Practical Perspectives

Introduction and Context

Classic congenital adrenal hyperplasia (CAH), caused by 21-hydroxylase deficiency, necessitates lifelong glucocorticoid (GC) replacement to address cortisol deficiency and suppress androgen overproduction. Traditional high-dose GC regimens carry significant long-term risks including growth impairment, obesity, and metabolic complications. The 2025 FDA approval of crinecerfont – a corticotropin-releasing factor type 1 receptor antagonist – enables a paradigm shift by reducing ACTH-driven androgen production, allowing for safer GC dosing focused on physiologic cortisol replacement rather than androgen suppression.

New Guideline Highlights

These recommendations, developed by 11 pediatric endocrinology experts, provide specific protocols for GC reduction in patients aged 4-17 years after initiating crinecerfont therapy. Core principles include:

• Individualized GC tapering based on growth velocity and androgen levels
• Maintaining GC doses above physiologic cortisol requirements
• Frequent monitoring during dose reduction phases
• Prioritizing normalization of bone age maturation and growth patterns

Updated Recommendations and Key Changes

This represents the first formal guidance for GC reduction in pediatric CAH following targeted non-glucocorticoid therapy. Key innovations include:

Parameter	Previous Approach	New Approach with Crinecerfont
GC Treatment Goal	Androgen suppression via supraphysiologic GC	Physiologic cortisol replacement only
Dosing Strategy	High-dose maintenance	Progressive reduction after crinecerfont initiation
Therapeutic Monitoring	Primarily androgens	Androgens plus growth velocity/bone age

Topic-by-Topic Recommendations

Initiation & Tapering Protocol

• Start crinecerfont per FDA labeling while maintaining current GC dose
• After 4 weeks: Begin GC reduction if 17-OHP and androgens are consistently near-normal
• Taper GC by 10-20% every 2-4 weeks

Monitoring Requirements

• Biochemical: Measure 17-OHP, androstenedione, testosterone monthly during tapering
• Clinical: Track growth velocity, weight, blood pressure, and signs of adrenal insufficiency weekly initially
• Bone age assessment every 6 months

Special Populations

• Rapid tapers may be considered in patients with severe Cushingoid features
• Slower tapers required in patients with prior adrenal crises
• Stress dosing must be maintained regardless of crinecerfont use

Expert Commentary and Insights

Dr. Natalie Nokoff, lead author, notes: “This represents the most substantial CAH treatment advancement in decades. We can now focus GC therapy on its essential purpose – cortisol replacement – rather than suppressing androgens at the cost of toxic side effects.” Experts emphasize cortisol sufficiency remains paramount, warning against reducing GC below 6-7 mg/m²/day hydrocortisone equivalent. Controversies exist regarding optimal biomarkers for monitoring, with some panelists advocating for androstenedione as the primary marker over 17-OHP.

Practical Implications

Implementation requires frequent lab monitoring and family education about adrenal insufficiency symptoms. Case example: Michael, a 10-year-old with CAH on hydrocortisone 15 mg/m²/day, started crinecerfont. After 8 weeks, his androstenedione normalized, enabling a 25% GC reduction over 12 weeks while maintaining normal growth velocity. The guidelines recommend developing clinic-specific protocols for lab coordination and emergency management during this transition period.

References

1. Nokoff NJ et al. Glucocorticoid Reduction After Starting Crinecerfont in Pediatric Patients With Classic CAH: Practical Perspectives. J Clin Endocrinol Metab. 2026. PMID: 42082437
2. FDA Approval Letter: Crinecerfont for CAH (2025)
3. Auchus RJ. Congenital Adrenal Hyperplasia in Adults. N Engl J Med. 2024;390(6):560-564
4. Speiser PW et al. Congenital Adrenal Hyperplasia Due to Steroid 21-Hydroxylase Deficiency. Endocrine Reviews. 2025;46(1):1-34