Benzinga | Aug 10, 2021 04:09PM EDT

Crinetics Pharmaceuticals' Oral ACTH Antagonist, CRN04894, Demonstrates Pharmacologic Proof-of-Concept with Dose-Dependent Cortisol Suppression in Single Ascending Dose Portion of Phase 1 Study

Crinetics Pharmaceuticals, Inc. (NASDAQ:CRNX), a clinical stage pharmaceutical company focused on the discovery, development, and commercialization of novel therapeutics for rare endocrine diseases and endocrine-related tumors, today announced positive preliminary findings from the single ascending dose (SAD) portion of a first-in-human Phase 1 clinical study with CRN04894 demonstrating pharmacologic proof-of-concept for this first-in-class, investigational, oral, nonpeptide adrenocorticotropic hormone (ACTH) antagonist that is being developed for the treatment of conditions of ACTH excess, including Cushing's disease and congenital adrenal hyperplasia.

"ACTH is the central hormone of the endocrine stress response. Even though we've known about its clinical significance for more than 100 years, there has never been an ACTH antagonist available to intervene in diseases of excess stress hormones. This is an important milestone for the field of endocrinology and for our company," said Scott Struthers, Ph.D., founder and chief executive officer of Crinetics. "I am extremely proud of our team that conceived, discovered and developed CRN04894 this far. This is the second molecule to emerge from our in-house discovery efforts and demonstrate pharmacologic proof of concept. I am very excited to see what it can do in upcoming clinical studies."

The 39 healthy volunteers who enrolled in the SAD cohorts were administered oral doses of CRN04894 (10 mg to 80 mg, or placebo) two hours prior to a challenge with synthetic ACTH. Analyses of basal cortisol levels (before ACTH challenge) showed that CRN04894 produced a rapid and dose-dependent reduction of cortisol by 25-56%. After challenge with a supra-pathophysiologic dose of ACTH (250 mcg), CRN04894 suppressed cortisol (as measured by AUC) up to 41%. After challenge with a disease-relevant dose of ACTH (1 mcg), CRN04894 showed a clinically meaningful reduction in cortisol AUC of 48%. These reductions in cortisol suggest that CRN04894 is bound with high affinity to its target receptor on the adrenal gland and blocking the activity of ACTH. CRN04894 was well tolerated in the healthy volunteers who enrolled in these SAD cohorts and all adverse events were considered mild.

"We are very encouraged by these single ascending dose data which clearly demonstrate proof of ACTH antagonism with CRN04894 exposure in healthy volunteers," stated Alan Krasner, M.D., chief medical officer of Crinetics. "We look forward to completing this study and assessing results from the multiple ascending dose cohorts. As a clinical endocrinologist, I recognize the pioneering nature of this work and eagerly look forward to further understanding the potential of CRN04894 for the treatment of diseases of ACTH excess."