Two-year CAHtalyst data show crinecerfont sustains androgen reduction and lowers glucocorticoid doses in children with congenital adrenal hyperplasia.
Two-year data from the phase 3 CAHtalyst Pediatric open-label extension show that crinecerfont (Crenessity; Neurocrine Biosciences) delivered sustained reductions in adrenal androgens and glucocorticoid doses while improving cardiometabolic outcomes in children and adolescents with classic congenital adrenal hyperplasia (CAH).
The findings, presented at the Pediatric Endocrine Society 2026 Annual Meeting in San Francisco, offer the longest follow-up yet for the corticotropin-releasing factor type 1 receptor (CRF1) antagonist in a pediatric population.
"These 2-year findings showed that CRENESSITY achieved durable reductions in both androgen levels and glucocorticoid doses in children and adolescents with classic congenital adrenal hyperplasia, a population particularly vulnerable to the long-term health impact of excess hormone exposure during growth and development," said Sanjay Keswani, MD, chief medical officer at Neurocrine Biosciences.¹
The analysis included 86 participants aged 4 to 17 years who completed up to 2 years of crinecerfont treatment in the CAHtalyst Pediatric open-label extension. The original randomized, placebo-controlled phase 3 trial enrolled 103 pediatric patients with classic CAH due to 21-hydroxylase deficiency.²
Hormonal control continued to improve through month 24. Mean adrenocorticotropic hormone (ACTH) decreased by 157 pg/mL from a baseline of 329 pg/mL, while mean 17-hydroxyprogesterone (17-OHP) fell by 1924 ng/dL from a baseline of 8682 ng/dL. Importantly, these reductions occurred despite a simultaneous decrease in mean daily glucocorticoid dose of 3.2 mg/m²/day hydrocortisone equivalents from a baseline of 16.4 mg/m²/day, suggesting that crinecerfont enabled a shift toward more physiologic glucocorticoid replacement.¹
Cardiometabolic improvements were notable. Among participants who were overweight or obese at baseline (BMI ≥85th percentile; n = 60), 60% achieved a clinically meaningful reduction in BMI standard deviation score (≥0.2) at month 24, and 23% moved below the 85th percentile. Among those with insulin resistance at baseline (n = 39), 61% no longer met criteria for insulin resistance by homeostatic model assessment at 2 years.¹
Androgen-related clinical outcomes also improved. Mean acne severity scores, assessed by visual analog scale, decreased progressively from 25.4 mm at baseline to an 11.0-mm reduction at month 24 among affected patients. Among males at Tanner stage 2 or above with elevated androstenedione-to-testosterone ratios, 36% achieved normalization by month 24. Hirsutism scores in female participants showed more modest and variable changes.¹
Classic CAH is a rare autosomal recessive disorder caused by 21-hydroxylase deficiency, affecting approximately 1 in 15,000 to 16,000 births.³ The mainstay of treatment has been lifelong glucocorticoid replacement, but supraphysiologic doses are typically required to suppress ACTH-driven adrenal androgen excess. This creates a treatment paradox: undertreating exposes patients to hyperandrogenism and its sequelae, including accelerated bone maturation and reduced adult height, while overtreating leads to glucocorticoid toxicity, including obesity, insulin resistance, and cardiovascular risk.²
Mimi Kim, MD, MSc, principal investigator for the CAHtalyst Pediatric study, noted that "excess androgens can accelerate bone age and drive early puberty, which can result in reduced final adult height," and that the findings "underscore the potential for CRENESSITY to redefine the treatment paradigm for patients with CAH."¹
Crinecerfont is an oral CRF1 antagonist that acts at the pituitary level to reduce ACTH secretion, thereby lowering adrenal androgen production through a non-glucocorticoid mechanism. The US Food and Drug Administration approved Crenessity in December 2024 for use in combination with glucocorticoids to control androgen levels in adults and children aged 4 years and older with classic CAH, based on the phase 3 CAHtalyst program—the largest clinical trial program ever conducted in classic CAH, enrolling 285 patients across pediatric and adult studies.²
These data come from an open-label extension without a concurrent control group, limiting causal inference. The sample size diminished from 103 at baseline to 86 completers, and analyses of subgroups (eg, those with baseline obesity or insulin resistance) involved even smaller numbers. No new safety signals were reported, and study retention exceeded 80% at 2 years, though detailed adverse event data were not included in the presentation summary. Final adult height outcomes, a critical endpoint in pediatric CAH, remain to be determined with longer follow-up.
