Data showed at least 50% decrease in 17-hydroxyprogesterone (17-OHP) and adrenocorticotropic hormone (ACTH) levels from baseline in more than 50% of patients who received NBI-74788 for 14 days.
The drug candidate also led to meaningful reductions in other biomarkers such as androstenedione and was found to be well tolerated without any serious adverse events.
Classic CAH is a rare genetic disorder affecting the adrenal glands.
It is caused by 21-hydroxylase enzyme deficiency and results in adrenal insufficiency, overgrowth of the adrenal glands, as well as excess androgen levels.
NBI-74788 is a potent, selective, orally-active, non-peptide antagonist of the corticotropin-releasing factor type 1 (CRF1) receptor. The drug candidate is expected to lower the CAH symptoms.
The open-label, multiple-dose, dose-escalation Phase II trial is being conducted to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of NBI-74788 in around 30 patients.
It includes a sequential-cohort design with three dose cohorts of NBI-74788, and each dose is administered for 14 consecutive days.
Study lead investigator Richard Auchus said: “The interim results from this Phase II study of NBI-74788 are encouraging, as they indicate a clinically meaningful reduction in key biomarkers.
“These data provide encouragement that NBI-74788 has potential as a new treatment option to help patients avoid the complications associated with current therapeutic options for classic CAH.”
The company intends to meet the US Food and Drug Administration (FDA) to discuss the registration programme for NBI-74788 in both adult and paediatric patients with CAH.