Animal experiment:

Male Sprague-Dawley rats are received at 175 to 200 g and housed in a 12 to 12 light cycle for 1 week before adrenalectomy. Rats are adrenalectomized at Neurocrine Biosciences, and NaCl is replenished. Adrenalectomy is verified by plasma corticosterone measurements. Seven days after adrenalectomy, rats are implanted with femoral vein catheters. After ~4 days, rats are prepared for blood sampling by attaching their catheters to PE50 tubing and a syringe, and acclimated to individual opaque sampling cages for 1 h. These cages allow sampling to occur without disturbance to the rat. Blood samples (0.3 mL) are taken after acclimation and blood volumes are replaced with 5 U/mL heparinized saline. Blood samples are stored on ice with EDTA. After a baseline blood sample, rats receive oral doses of either vehicle at 5 mL/kg or the respective drug (including Verucerfont) in the same volume of vehicle. In each case, the dose is 10 mg/kg, based on prior pharmacokinetic studies showing that this dose results in adequate and comparable exposure. Blood samples are taken 1, 2, 3, 4, and 6 h later. Plasma is separated by centrifugation at 4℃ and stored at -80 ℃ for subsequent measurement of ACTH by radioimmunoassay[1].

Verucerfont is a corticotropin-releasing factor receptor 1 (CRF1) antagonist with IC50s of ~6.1, >1000 and >1000 nM for CRF1, CRF2, and CRF-BP, respectively.

Post hoc analysis shows that the prototypic non-peptide CRF1 receptor antagonist NBI30775 (R121919) and Verucerfont are both significantly different from vehicle, CP-316 311, and pexacerfont (PPost hoc analysis shows that both NBI30775 and Verucerfont inhibit ACTH release throughout the following 6 h of measurement (P<0.001 vs vehicle at each time-point, and vs the respective pretreatment baseline)[1].

References:
[1]. Schwandt ML, et al. The CRF1 Antagonist Verucerfont in Anxious Alcohol-Dependent Women: Translation of Neuroendocrine, But not of Anti-Craving Effects. Neuropsychopharmacology. 2016 Nov;41(12):2818-2829.