Abstract
PI3Kδ plays an important role controlling immune cell function and has therefore been identified as a potential target for the treatment of immunological disorders. This article highlights our work toward the identification of a potent, selective, and efficacious PI3Kδ inhibitor. Through careful SAR, the successful replacement of a polar pyrazole group by a simple chloro or trifluoromethyl group led to improved Caco-2 permeability, reduced Caco-2 efflux, reduced hERG PC activity, and increased selectivity profile while maintaining potency in the CD69 hWB assay. The optimization of the aryl substitution then identified a 4'-CN group that improved the human/rodent correlation in microsomal metabolic stability. Our lead molecule is very potent in PK/PD assays and highly efficacious in a mouse collagen-induced arthritis model.
MeSH terms
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Animals
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Antigens, CD / metabolism
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Antigens, Differentiation, T-Lymphocyte / metabolism
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Arthritis, Experimental / drug therapy*
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Caco-2 Cells / drug effects
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Caco-2 Cells / immunology
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Dogs
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Drug Evaluation, Preclinical / methods*
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ERG1 Potassium Channel / metabolism
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Enzyme Inhibitors / chemistry
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Enzyme Inhibitors / pharmacology*
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Female
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Humans
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Immune System Diseases / drug therapy
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Isoenzymes / antagonists & inhibitors
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Isoenzymes / metabolism
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Lectins, C-Type / metabolism
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Male
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Mice, Inbred BALB C
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Phosphoinositide-3 Kinase Inhibitors*
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Pyrazoles / chemistry
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Pyrazoles / metabolism
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Pyrazoles / pharmacology
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Rabbits
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Structure-Activity Relationship*
Substances
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Antigens, CD
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Antigens, Differentiation, T-Lymphocyte
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CD69 antigen
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ERG1 Potassium Channel
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Enzyme Inhibitors
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Isoenzymes
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KCNH2 protein, human
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Lectins, C-Type
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Phosphoinositide-3 Kinase Inhibitors
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Pyrazoles