SAN DIEGO, July 1, 2026
Neurocrine Biosciences announced the initiation of a Phase 2 clinical trial evaluating crinecerfont (CRENESSITY®) in children aged 3 months to under 4 years with classic congenital adrenal hyperplasia (CAH). The study is designed to assess the safety and tolerability of the therapy in a patient population for whom no approved treatment currently exists beyond glucocorticoid replacement. Conducted under an FDA Pediatric Written Request, the trial is expected to support a planned supplemental New Drug Application (sNDA) seeking to expand the approved U.S. indication of CRENESSITY, which is currently approved for adults and children aged four years and older. Neurocrine stated that the study reflects its continued commitment to addressing the unmet needs of infants and young children living with this rare endocrine disorder.
Phase 2 Study Targets Young Pediatric CAH Population
The open-label, single-arm Phase 2 trial will enroll approximately 20 children between 3 months and under 4 years of age with classic CAH. Participants will receive treatment over a 24-week period, with the primary objective focused on evaluating the safety and tolerability of crinecerfont. Secondary endpoints include assessments of pharmacokinetics and the drug’s pharmacodynamic effects on hormone biomarkers associated with CAH. The study aims to generate clinical evidence supporting the expansion of CRENESSITY’s approved use to younger pediatric patients, a population that currently lacks therapies specifically designed to reduce excess androgen production while minimizing exposure to high-dose glucocorticoids.
Development Program Advances Pediatric Expansion
Neurocrine also announced that enrollment has been completed in a separate European Union Phase 2 study evaluating crinecerfont in children from birth to under two years of age with classic CAH. Together, the U.S. and European pediatric studies are intended to expand clinical evidence for the therapy across younger age groups. Crinecerfont received FDA approval in 2024 as the first new therapeutic advancement for classic CAH in more than 70 years. The selective oral CRF1 receptor antagonist works by reducing excess adrenocorticotropic hormone (ACTH) production through a non-glucocorticoid mechanism, enabling patients to maintain more physiologic glucocorticoid replacement while controlling excess adrenal androgen production.
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Neurocrine Expands Clinical Development of CRENESSITY
Classic congenital adrenal hyperplasia is a rare inherited disorder that disrupts cortisol production and often requires lifelong glucocorticoid therapy. High glucocorticoid doses used to suppress androgen excess can contribute to significant long-term complications, particularly during childhood growth and development. Neurocrine believes crinecerfont has the potential to reduce reliance on supraphysiologic glucocorticoid dosing while improving disease management in younger patients. The newly initiated Phase 2 study represents another step in the company’s broader strategy to expand CRENESSITY’s clinical use and address significant unmet medical needs across pediatric and adult CAH populations.
Source: Neurocrine Biosciences press release
