Discovery of oxa-sultams as RORc inverse agonists showing reduced lipophilicity, improved selectivity and favorable ADME properties.

Modification of the δ-sultam ring of RORc inverse agonist 2 led to the discovery of more polar oxa-sultam 65. The less lipophilic inverse agonist (65) displayed high potency in a biochemical assay, which translated into inhibition of IL-17 production in human peripheral blood mononuclear cells. The successful reduction of lipophilicity of this new analog gave rise to additional improvements in ROR selectivity and aqueous kinetic solubility, as well as reduction in plasma protein binding, while maintaining high cellular permeability.

Discovery of imidazo[1,5-a]pyridines and -pyrimidines as potent and selective RORc inverse agonists.

The nuclear receptor (NR) retinoic acid receptor-related orphan receptor gamma (RORγ, RORc, or NR1F3) is a promising target for the treatment of autoimmune diseases. RORc is a critical regulator in the production of the pro-inflammatory cytokine interleukin-17. We discovered a series of potent and selective imidazo[1,5-a]pyridine and -pyrimidine RORc inverse agonists. The most potent compounds displayed >300-fold selectivity for RORc over the other ROR family members, PPARγ, and NRs in our cellular selectivity panel. The favorable potency, selectivity, and physiochemical properties of GNE-0946 (9) and GNE-6468 (28), in addition to their potent suppression of IL-17 production in human primary cells, support their use as chemical biology tools to further explore the role of RORc in human biology.

Histamine-induced actin polymerization in human eosinophils: an imaging approach for histamine H4 receptor.

Image-based screening, a new and flexible tool in the drug discovery cascade, is amenable to many different targets. This article describes a particular use of the Cellomics ArrayScan in developing a functional screen for histamine H(4) receptor (H(4)R) antagonists that have potential utility in inflammatory diseases of the airways such as asthma, with H(4)R being expressed on a wide variety of immune cells including eosinophils. Exposure to histamine causes eosinophils to migrate from the bloodstream into the tissue where they contribute to inflammation. Migration is manifested through rearrangements of the actin cytoskeleton and phalloidin, a biological peptide, selectively binds F-actin over G-actin and can be used to detect these cytoskeletal changes mediating inflammatory function. A fluorescent conjugate of phalloidin was used to visualize histamine-induced actin polymerization in human eosinophils on the Cellomics ArrayScan. Inhibition of this phenomenon by commercially available histamine receptor antagonists was measured. The selective H(4)R antagonist JNJ7777120 inhibited histamine-induced actin polymerization in eosinophils most potently. This assay illustrates that this phenomenon is mediated through the H(4)R and that the image-based format has enhanced screening utility for identifying selective H(4)R antagonists over traditional flow cytometry methods.