Regulation of Endogenous (Male) Rodent GLP-1 Secretion and Human Islet Insulin Secretion by Antagonism of Somatostatin Receptor 5.

Incretin and insulin responses to nutrient loads are suppressed in persons with diabetes, resulting in decreased glycemic control. Agents including sulfonylureas and dipeptidyl peptidase-4 inhibitors (DPP4i) partially reverse these effects and provide therapeutic benefit; however, their modes of action limit efficacy. Because somatostatin (SST) has been shown to suppress insulin and glucagonlike peptide-1 (GLP-1) secretion through the Gi-coupled SST receptor 5 (SSTR5) isoform in vitro, antagonism of SSTR5 may improve glycemic control via intervention in both pathways. Here, we show that a potent and selective SSTR5 antagonist reverses the blunting effects of SST on insulin secretion from isolated human islets, and demonstrate that SSTR5 antagonism affords increased levels of systemic GLP-1 in vivo. Knocking out Sstr5 in mice provided a similar increase in systemic GLP-1 levels, which were not increased further by treatment with the antagonist. Treatment of mice with the SSTR5 antagonist in combination with a DPP4i resulted in increases in systemic GLP-1 levels that were more than additive and resulted in greater glycemic control compared with either agent alone. In isolated human islets, the SSTR5 antagonist completely reversed the inhibitory effect of exogenous SST-14 on insulin secretion. Taken together, these data suggest that SSTR5 antagonism should increase circulating GLP-1 levels and stimulate insulin secretion (directly and via GLP-1) in humans, improving glycemic control in patients with diabetes.

Novel Autotaxin Inhibitors for the Treatment of Osteoarthritis Pain: Lead Optimization via Structure-Based Drug Design.

In an effort to develop a novel therapeutic agent aimed at addressing the unmet need of patients with osteoarthritis pain, we set out to develop an inhibitor for autotaxin with excellent potency and physical properties to allow for the clinical investigation of autotaxin-induced nociceptive and neuropathic pain. An initial hit identification campaign led to an aminopyrimidine series with an autotaxin IC50 of 500 nM. X-ray crystallography enabled the optimization to a lead compound that demonstrated favorable potency (IC50 = 2 nM), PK properties, and a robust PK/PD relationship.

Mild Pd-catalyzed N-arylation of methanesulfonamide and related nucleophiles: avoiding potentially genotoxic reagents and byproducts.

A convenient, general, and high yielding Pd-catalyzed cross-coupling of methanesulfonamide with aryl bromides and chlorides is reported. The use of this method eliminates concern over genotoxic impurities that can arise when an aniline is reacted with methanesulfonyl chloride. The application of this method to the synthesis of dofetilide is also reported.