Peptide-based long-acting co-agonists of GLP-1 and cholecystokinin 1 receptors as novel anti-diabesity agents.

The combined use of gastrointestinal hormones for treating metabolic diseases is gaining increasing attention. It was documented previously that co-administration of a cholecystokinin receptor-1 receptor (CCK-1R) agonist with a glucagon-like peptide-1 receptor (GLP-1R) agonist exerted improved effects on metabolic improvements in obese rodents. Here, we reported a series of novel GLP-1R/CCK-1R co-agonists constructed by linking the C-terminus of a GLP-1R agonist (native GLP-1 or Xenopus GLP-1) to the N-terminus of a CCK-1R selective agonist NN9056. The stability of co-agonists was further enhanced by introducing an albumin binding motif. In vitro functional assays revealed that the co-agonists retained full agonism potency on GLP-1R and CCK-1R. Particularly, 2a and 2c showed higher hypoglycemic and insulinotropic activities than NN9056 and semaglutide. The glucose-lowering durations and PK profiles of 2a and 2c were comparable to those of semaglutide. Desirably, in diet induced obesity (DIO) mice, 2a and 2c exhibited superior metabolic benefits to NN9056 and semaglutide in reducing food intake, inducing body weight loss, and regulating lipid metabolism. In short- and long-term studies in diabetic db/db mice, 2a and 2c showed enhanced effects on HbA1c, glucose tolerance, and pancreas function restoration compared with semaglutide. Importantly, no side effects, toxicities, or pancreatic inflammation were caused by 2a and 2c treatments. These preclinical studies suggest that the pharmacological effects of CCK-1 and GLP-1 pathways can be harnessed in a single fusion peptide, yielding a promising combination therapy strategy for treating metabolic disorders.

Stapled and Xenopus Glucagon-Like Peptide 1 (GLP-1)-Based Dual GLP-1/Gastrin Receptor Agonists with Improved Metabolic Benefits in Rodent Models of Obesity and Diabetes.

Diabetes is characterized by pancreas dysfunction and is commonly associated with obesity. Hypoglycemic agents capable of improving ß-cell function and reducing body weight therefore are gaining increasing interest. Though glucagon-like peptide 1 receptor (GLP-1R)/cholecystokinin 2 receptor (CCK-2R) dual agonist ZP3022 potently increases ß-cell mass and improves glycemic control in diabetic db/db mice, the in vivo half-life (t1/2) is short, and its body weight reducing activity is limited. Here, we report the discovery of a series of novel GLP-1R/CCK-2R dual agonists. Starting from Xenopus GLP-1, dual cysteine mutation was conducted followed by covalent side chain stapling and albumin binder incorporation, resulting in a stabilized secondary structure, increased agonist potency, and improved stability. Further C-terminal conjugation of gastrin-6 generated GLP-1R/CCK-2R dual agonists, among which 6a and 6b showed higher stability and hypoglycemic activity than liraglutide and ZP3022. Desirably, 6a and 6b exhibited prominent metabolic benefits in diet-induced obesity mice without causing nausea responses and exerted considerable effects on ß-cell restoration in db/db mice. These preclinical studies suggest the potential role of GLP-1R/CCK-2R dual agonists as effective agents for treating diabetes and related metabolic disorders.