Biopharmaceutical company Neurocrine Biosciences Inc (Nasdaq:NBIX) announced on Wednesday the initiation of its Phase 2 clinical study to assess the safety and tolerability of crinecerfont in children aged 3 months to under 4 years with classic congenital adrenal hyperplasia (CAH).

Crinecerfont, marketed as CRENESSITY, is approved in the United States as an adjunctive treatment to glucocorticoid replacement to control androgens in adult and paediatric patients aged 4 years and older with classic CAH.

The Phase 2 open-label, single-arm study consists of a 24-week treatment period with a primary objective of assessing the safety and tolerability of crinecerfont in 20 participants aged 3 months to under 4 years with classic CAH. Secondary objectives include evaluation of the pharmacokinetics and pharmacodynamic effects of crinecerfont on hormone biomarkers. This study is expected to support a planned supplemental New Drug Application to expand the approved US indication to include patients under 4 years of age.

Separately, Neurocrine has achieved target enrolment for a Phase 2 study in the European Union to evaluate the safety and tolerability of crinecerfont in children from birth to under 2 years of age with classic CAH.

Approved by the US Food and Drug Administration in 2024, crinecerfont is a potent and selective oral corticotropin-releasing factor type 1 receptor (CRF1) antagonist that reduces elevated adrenocorticotropic hormone (ACTH) secretion at the source and the resulting downstream excess adrenal androgens through a non-GC mechanism.