CRN04777, Oral SST5 Agonist


Our team has discovered potent, drug-like, selective, nonpeptide, SST5 receptor agonists designed to suppress insulin secretion and prevent the hypoglycemia observed in children who have congenital hyperinsulinism.

For the Treatment of Congenital Hyperinsulinism


Infants with congenital hyperinsulinism (congenital HI) are born with mutations that cause excess secretion of the pancreatic hormone insulin, resulting in profound hypoglycemia, a very low level of blood glucose. This loss of homeostatic control of blood glucose levels can lead to seizures, developmental disorders, learning disabilities, coma, and even death.

We have identified a product candidate that has entered preclinical development. Our ongoing efforts focus on identifying and advancing into human clinical trials the first oral, selective, nonpeptide, somatostatin type 5 receptor (SST5) agonist designed to treat congenital HI.

Selective Somatostatin 5 (SST5) and Somatostatin 2 (SST2) Nonpeptide Agonists Potently Suppress Glucose- and Tolbutamide-Stimulated Dynamic Insulin Secretion From Isolated Human Islets


Insulin Regulation with Selective SST5 Agonist (congenital hyperinsulinism)

Congenital Hyperinsulinism Poster ENDO 2021

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Authors

Elizabeth Rico, PhD, Jian Zhao, PhD, Mi Chen, BS, Ana Karin Kusnetzow, PhD, Yun Fei Zhu, PhD, Stephen F. Betz, PhD.
Crinetics Pharmaceuticals, San Diego, CA, USA.

Disclosures

E. Rico: Employee; Self; Crinetics Pharmaceuticals. J. Zhao: Employee; Self; Crinetics Pharmaceuticals. M. Chen: Employee; Self; Crinetics Pharmaceuticals. A.K. Kusnetzow: Employee; Self; Crinetics Pharmaceuticals. Y. Zhu: Employee; Self; Crinetics Pharmaceuticals. S.F. Betz: Employee; Self; Crinetics Pharmaceuticals.

Abstract

Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in newborns and infants and arises from dysregulated insulin secretion. Rapid recognition and treatment are vital to prevent seizures, permanent developmental delays, coma, or even death. Very few medical options exist to treat congenital HI patients: the KATP channel activator diazoxide, the injectable somatostatin receptor peptide agonists octreotide and lanreotide, or chronic glucose infusions. However, side effects and/or limited efficacy render these therapies inadequate for many patients.

Somatostatin is a 14-amino acid peptide hormone with a broad spectrum of biological actions, which are regulated through five somatostatin receptor subtypes (SST1-SST5). Somatostatin’s common physiological role is to down- regulate secretion of other hormones in various tissues. Its role in the maintenance of euglycemia is to regulate insulin and glucagon secretion from pancreatic β- and α-cells, respectively. Somatostatin regulates insulin secretion by decreasing the intracellular levels of cAMP, inhibition of voltage-gated calcium channels (VGCC), activation of the G protein-activated inward rectifier K+ channel (GIRK), and direct inhibition of insulin exocytosis.

Several studies have evaluated the effect of somatostatin, somatostatin peptide analogs, and a limited number of nonpeptide somatostatin receptor agonists on insulin secretion in static assays using isolated human islets.

However, the lack of highly selective agonists has made the interpretation of the contribution of SST receptor sub-types difficult to discern. Our programs for the treatment of hyperinsulinism, acromegaly, and other indications have led to the development of selective nonpeptide SST2, SST3, SST4, and SST5 agonists, possessing EC50s < 1 nM in cell-based assays of receptor activation and selectivity > 130 times over the other members of the family. The ability of these selective nonpeptide agonists to regulate glucose- and tolbutamide- stimulated dynamic insulin secretion from human islets was evaluated using a perifusion system (Biorep, FL).

We found that selective SST2 and SST5 agonists potently suppressed dynamic insulin secretion in contrast to SST3 or SST4 selective agonists. Importantly, SST5 agonists were shown to have a greater effect than selective SST2 agonists or diazoxide, demonstrating their potential utility in human conditions such as congenital HI. In addition, SST5 activation is also known to have a smaller effect on glucagon secretion and is also less prone to agonist-driven desensitization than SST2 activation. Taken together, these studies support our program to identify, characterize, and develop potent, nonpeptide, orally-bioavailable, selective SST5 agonists with appropriate pharmaceutical and safety characteristics for the treatment of congenital HI.

Discovery and Identification of Late Stage, Selective, Nonpeptide, Somatostatin Subtype 5 (SST5) Agonists for the Treatment of Hyperinsulinemic Hypoglycemia

ENDO Online 2020 Crinetics SST5

Melissa A. Fowler, Jian Zhao, Emmanuel Sturchler, Elizabeth Rico-Bautista, Rosalia de Necochea-Campion, Jon Athanacio, Taylor A. Kredel, Agnes Antwan, Michael Johns, Oleg Tsivkoski, Shimiao Wang, Rosa Luo, Ana K. Kusnetzow, Ajay Madan, R. Scott Struthers, Stacy Markison, Yun Fei Zhu, Stephen F. Betz. ENDO Online 2020. June 8-22, 2020.

Congenital Hyperinsulinism Poster ENDO 2021

Selective Nonpeptide Somatostatin Receptor Subtype 5 (sst5) Agonists Suppress Glucose and Sulfonylurea-induced Insulin Secretion in Rats

Selective Nonpeptide Somatostatin Receptor Subtype 5 (sst5) Agonists Suppress Glucose- and Sulfonylurea-induced Insulin Secretion in Rats

Emmanuel Sturchler, Melissa A. Fowler, Jon Athanacio, Taylor A. Kredel, Michael Johns, Jian Zhao, Shimiao Wang, Rosa Luo, Ana Karin Kusnetzow, Yun Fei Zhu, Ajay Madan, R. Scott Struthers, Stephen F. Betz, Stacy Markison. ENDO 2019. March 23-26, 2019; New Orleans.


Selective Nonpeptide Somatostatin Subtype 5 (sst5) Agonists Suppress Induced Insulin Secretion in Pancreatic Islets from both Rats and Healthy Human Donors.

Selective Nonpeptide Somatostatin Subtype 5 (sst5) Agonists Suppress Induced Insulin Secretion in Pancreatic Islets from both Rats and Healthy Human Donors.

Elizabeth Rico-Bautista, Ana Karin Kusnetzow, Melissa A. Fowler, Jon Athanacio, Taylor A. Kredel, Jian Zhao, Shimiao Wang, Stacy Markison, Yun Fei Zhu, R. Scott Struthers, Stephen F. Betz. ENDO 2019. March 23-26, 2019; New Orleans.