Neurocrine Biosciences Inc. (NASDAQ: NBIX) presented two-year data from its Phase 3 CAHtalyst Adult study showing that approximately 70% of adult patients with classic congenital adrenal hyperplasia achieved physiologic-range glucocorticoid dosing when treated with CRENESSITY (crinecerfont). The findings were presented at the American Association of Clinical Endocrinology 2026 Annual Meeting in Las Vegas.

The study demonstrated that patients maintained a mean 38% reduction in glucocorticoid doses from baseline through 24 months of treatment. At month 24, 103 of 149 participants achieved physiologic glucocorticoid doses of ≤11 mg/m²/day hydrocortisone equivalents, compared to zero participants at baseline when the mean daily dose was 17.6 mg/m²/day.

Among the 20 participants originally taking dexamethasone, 75% transitioned to a dexamethasone-free regimen. Additionally, 62% of patients taking more than two daily hydrocortisone doses eliminated at least one dose. These reductions occurred without worsening androstenedione levels, indicating androgen control was maintained.

The treatment showed over 80% study retention at two years with no new safety signals observed, according to the company's press release. Common side effects in adults included tiredness, headache, dizziness, joint pain, back pain, decreased appetite, and muscle pain.

CRENESSITY received FDA approval in December 2024 for treating classic congenital adrenal hyperplasia in adults and children aged four and older. The medication works as a corticotropin-releasing factor type 1 receptor antagonist, reducing excess adrenocorticotropic hormone and adrenal androgens through a non-glucocorticoid mechanism.

Classic congenital adrenal hyperplasia is a rare genetic condition affecting adrenal steroid hormone production. Traditional treatment has relied on supraphysiologic glucocorticoid doses, which can lead to long-term health complications including metabolic issues, cardiovascular disease, and osteoporosis.