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Abstract Disease heterogeneity is as major issue in Type II Diabetes Mellitus (T2DM), and this patient inter-variability might not be sufficiently reflected by measurements of glycated haemoglobin (HbA1c). Β-cell dysfunction and β-cell death are initiating factors in development of T2DM. In fact, β-cells are known vanish prior to the development of T2DM, and autopsy of overt T2DM patients have shown a 60% reduction in β-cell mass. As the decline in β-cell function and mass have been proven to be pathological traits in T2DM, methods for evaluating β-cell loss is becoming of more interest. However, evaluation of β-cell death or loss is currently invasive and unattainable for the vast majority of diabetes patients. Serological markers, reflecting β-cell loss would be advantageous to detect and monitor progression of T2DM. Biomarkers with such capacities could be neo-epitopes of proteins with high β-cell specificity containing post translational modifications. Such tools may segregate T2DM patients into more appropriate treatment groups, based on their β-cell status, which is currently not possible. Presently individuals presenting with adequately elevated levels of both insulin and glucose are classified as T2DM patients, while an important subdivision of those is pending, namely those patients with sufficient β-cell capacity and those without. This may warrant two very different treatment options and patient care paths. Serological biomarkers reflecting β-cell health status may also assist development of new drugs for T2DM and aid physicians in better characterization of individual patients and tailor individual treatments and patient care protocols.

Dual amylin and calcitonin receptor agonists (DACRAs) are novel candidates for treatment of T2D and obesity due to their beneficial effects on body weight, blood glucose and insulin sensitivity, effects that are superior to those of amylin. However, it is unknown how dual receptor activation by DACRAs compare to activation of either the amylin or the calcitonin receptor in vivo, and to what extent the calcitonin receptor is involved in the beneficial metabolic effects of DACRAs. In this study, we compared the effects of a highly potent DACRA, KBP, rat amylin (rAMY), rat calcitonin (rCT) and the combination of rAMY and rCT on long term efficacy on body weight, food intake and glucose tolerance. High fat fed Sprague Dawley rats were treated 4 weeks with KBP (5 µg/kg/day), rAMY (300 µg/kg/day), rCT, (300 µg/kg/day) and the combination of rAMY and rCT (300+300 µg/kg/day). To compensate for the different activity profiles, peptides were delivered by continuous subcutaneous infusion. Chronic treatment with KBP, rAMY and the combination of rAMY and rCT resulted in a 17%, 11% and 8% vehicle-corrected weight loss, respectively, while rCT alone had no effect. All treatments significantly reduced food intake in the initial phase of the study, while KBP and rAMY resulted in a prolonged reduced food intake. Interestingly, KBP was superior in terms of body weight loss (p<0.001) even though rAMY and KBP reduced the accumulated food intake equally. Moreover, KBP and rAMY improved oral glucose tolerance with significantly reduced insulin levels. Again, KBP was superior to the other treatments (p<0.001). In conclusion, dual activation of amylin and calcitonin receptors by KBP has beneficial effects on body weight and glucose tolerance superior to that of activating either receptor alone. This was despite correcting for the different activity of the peptides. Understanding of the dual or single receptor activation mechanisms is high pharmaceutical interest. Disclosure: A.T. Larsen: None. N. Sonne: None. K.V. Andreassen: Employee; Self; Nordic Bioscience. M.A. Karsdal: Employee; Self; Nordic Bioscience. K. Henriksen: Employee; Self; Nordic Bioscience. Employee; Spouse/Partner; Novo Nordisk A/S. Stock/Shareholder; Self; Nordic Bioscience. Other Relationship; Self; Nordic Bioscience. [ABSTRACT FROM AUTHOR]

The present study investigated a novel oral dual amylin and calcitonin receptor agonist (DACRA), KBP-042, in head-to-head comparison with salmon calcitonin (sCT) with regard to in vitro receptor pharmacology, ex vivo pancreatic islet studies, and in vivo proof of concept studies in diet-induced obese (DIO) and Zucker diabetic fatty (ZDF) rats. In vitro, KBP-042 demonstrated superior binding affinity and activation of amylin and calcitonin receptors, and ex vivo, KBP-042 exerted inhibitory action on stimulated insulin and glucagon release from isolated islets. In vivo, KBP-042 induced a superior and pronounced reduction in food intake in conjunction with a sustained pair-fed corrected weight loss in DIO rats. Concomitantly, KBP-042 improved glucose homeostasis and reduced hyperinsulinemia and hyperleptinemia in conjunction with enhanced insulin sensitivity. In ZDF rats, KBP-042 induced a superior attenuation of diabetic hyperglycemia and alleviated impaired glucose and insulin tolerance. Concomitantly, KBP-042 preserved insulinotropic and induced glucagonostatic action, ultimately preserving pancreatic insulin and glucagon content. In conclusion, oral KBP-042 is a novel DACRA, which exerts antiobesity and antidiabetic efficacy by dual modulation of insulin sensitivity and directly decelerating stress on the pancreatic α- and β-cells. These results could provide the basis for oral KBP-042 as a novel therapeutic agent in type 2 diabetes., (Copyright © 2014 the American Physiological Society.)