Phase 3 Trial of Crinecerfont in Adult Congenital Adrenal Hyperplasia.

BACKGROUND: Adrenal insufficiency in patients with classic 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) is treated with glucocorticoid replacement therapy. Control of adrenal-derived androgen excess usually requires supraphysiologic glucocorticoid dosing, which predisposes patients to glucocorticoid-related complications. Crinecerfont, an oral corticotropin-releasing factor type 1 receptor antagonist, lowered androstenedione levels in phase 2 trials involving patients with CAH. METHODS: In this phase 3 trial, we randomly assigned adults with CAH in a 2:1 ratio to receive crinecerfont or placebo for 24 weeks. Glucocorticoid treatment was maintained at a stable level for 4 weeks to evaluate androstenedione values, followed by glucocorticoid dose reduction and optimization over 20 weeks to achieve the lowest glucocorticoid dose that maintained androstenedione control (≤120% of the baseline value or within the reference range). The primary efficacy end point was the percent change in the daily glucocorticoid dose from baseline to week 24 with maintenance of androstenedione control. RESULTS: All 182 patients who underwent randomization (122 to the crinecerfont group and 60 to the placebo group) were included in the 24-week analysis, with imputation of missing values; 176 patients (97%) remained in the trial at week 24. The mean glucocorticoid dose at baseline was 17.6 mg per square meter of body-surface area per day of hydrocortisone equivalents; the mean androstenedione level was elevated at 620 ng per deciliter. At week 24, the change in the glucocorticoid dose (with androstenedione control) was -27.3% in the crinecerfont group and -10.3% in the placebo group (least-squares mean difference, -17.0 percentage points; P<0.001). A physiologic glucocorticoid dose (with androstenedione control) was reported in 63% of the patients in the crinecerfont group and in 18% in the placebo group (P<0.001). At week 4, androstenedione levels decreased with crinecerfont (-299 ng per deciliter) but increased with placebo (45.5 ng per deciliter) (least-squares mean difference, -345 ng per deciliter; P<0.001). Fatigue and headache were the most common adverse events in the two trial groups. CONCLUSIONS: Among patients with CAH, the use of crinecerfont resulted in a greater decrease from baseline in the mean daily glucocorticoid dose, including a reduction to the physiologic range, than placebo following evaluation of adrenal androgen levels. (Funded by Neurocrine Biosciences; CAHtalyst ClinicalTrials.gov number, NCT04490915.).

Phase 3 Trial of Crinecerfont in Pediatric Congenital Adrenal Hyperplasia.

BACKGROUND: Children with classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency require treatment with glucocorticoids, usually at supraphysiologic doses, to address cortisol insufficiency and reduce excess adrenal androgens. However, such treatment confers a predisposition to glucocorticoid-related complications. In 2-week phase 2 trials, patients with CAH who received crinecerfont, a new oral corticotropin-releasing factor type 1 receptor antagonist, had decreases in androstenedione levels. METHODS: In this phase 3, multinational, randomized trial, we assigned pediatric participants with CAH, in a 2:1 ratio, to receive crinecerfont or placebo for 28 weeks. A stable glucocorticoid dose was maintained for 4 weeks, and the dose was then adjusted to a target of 8.0 to 10.0 mg per square meter of body-surface area per day (hydrocortisone dose equivalents), provided that the androstenedione level was controlled (≤120% of the baseline level or within the reference range). The primary efficacy end point was the change in the androstenedione level from baseline to week 4. A key secondary end point was the percent change in the glucocorticoid dose from baseline to week 28 while androstenedione control was maintained. RESULTS: A total of 103 participants underwent randomization, of whom 69 were assigned to crinecerfont and 34 to placebo; 100 (97%) remained in the trial at 28 weeks. At baseline, the mean glucocorticoid dose was 16.4 mg per square meter per day, and the mean androstenedione level was 431 ng per deciliter (15.0 nmol/liter). At week 4, androstenedione was substantially reduced in the crinecerfont group (-197 ng per deciliter [-6.9 nmol/liter]) but increased in the placebo group (71 ng per deciliter [2.5 nmol/liter]) (least-squares mean difference [LSMD], -268 ng per deciliter [-9.3 nmol/liter]; P<0.001); the observed mean androstenedione value, obtained before the morning glucocorticoid dose, was 208 ng per deciliter (7.3 nmol/liter) in the crinecerfont group, as compared with 545 ng per deciliter (19.0 nmol/liter) in the placebo group. At week 28, the mean glucocorticoid dose had decreased (while androstenedione control was maintained) by 18.0% with crinecerfont but increased by 5.6% with placebo (LSMD, -23.5 percentage points; P<0.001). Headache, pyrexia, and vomiting were the most common adverse events. CONCLUSIONS: In this phase 3 trial, crinecerfont was superior to placebo in reducing elevated androstenedione levels in pediatric participants with CAH and was also associated with a decrease in the glucocorticoid dose from supraphysiologic to physiologic levels while androstenedione control was maintained. (Funded by Neurocrine Biosciences; CAHtalyst Pediatric ClinicalTrials.gov number, NCT04806451.).