Identification of a Potent, Selective, and Efficacious Phosphatidylinositol 3-Kinase δ (PI3Kδ) Inhibitor for the Treatment of Immunological Disorders.

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.

Discovery of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent and selective PI3Kδ inhibitors.

As demonstrated in preclinical animal models, the disruption of PI3Kδ expression or its activity leads to a decrease in inflammatory and immune responses. Therefore, inhibition of PI3Kδ may provide an alternative treatment for autoimmune diseases, such as RA, SLE, and respiratory ailments. Herein, we disclose the identification of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent, selective and orally bioavailable PI3Kδ inhibitors. The lead compound demonstrated efficacy in an in vivo mouse KLH model.

Discovery and SAR of pyrrolo[2,1-f][1,2,4]triazin-4-amines as potent and selective PI3Kδ inhibitors.

Aberrant Class I PI3K signaling is a key factor contributing to many immunological disorders and cancers. We have identified 4-amino pyrrolotriazine as a novel chemotype that selectively inhibits PI3Kδ signaling despite not binding to the specificity pocket of PI3Kδ isoform. Structure activity relationship (SAR) led to the identification of compound 30 that demonstrated efficacy in mouse Keyhole Limpet Hemocyanin (KLH) and collagen induced arthritis (CIA) models.

Identification of novel functional inhibitors of 17beta-hydroxysteroid dehydrogenase type III (17beta-HSD3).

BACKGROUND: Endocrine therapy of prostate cancer (PCa) relies on agents which disrupt the biosynthesis of testosterone in the testis and/or by direct antagonism of active hormone on the androgen receptor (AR) in non-gonadal target tissues of hormone action such as the prostate. METHODS: In an effort to evaluate new therapies which could inhibit gonadal or non-gonadal testosterone biosynthesis, we developed high throughput biochemical and cellular screening assays to identify inhibitors of 17beta-hydroxysteroid dehydrogenase type III (17beta-HSD3), the enzyme catalyzing the conversion of androstenedione (AdT) to testosterone. RESULTS: Initial screening efforts identified a natural product, 18beta-glycyrrhetinic acid, and a novel derivative of AdT, 3-O-benzylandrosterone, as potent inhibitors of the enzyme. Further efforts led to the identification of several classes of non-steroidal, low molecular weight compounds that potently inhibited 17beta-HSD3 enzymatic activity. One of the most potent classes of 17beta-HSD3 inhibitors was a series of anthranilamide small molecules identified from a collection of compounds related to non-steroidal modulators of nuclear hormone receptors. The anthranilamide based 17beta-HSD3 inhibitors were exemplified by BMS-856, a compound displaying low nanomolar inhibition of 17beta-HSD3 enzymatic activity. In addition, this series of compounds displayed potent inhibition of 17beta-HSD3-mediated cellular conversion of AdT to testosterone and inhibited the 17beta-HSD3-mediated conversion of testosterone necessary to promote AR-dependent transcription. CONCLUSIONS: The identification of non-steroidal functional inhibitors of 17beta-HSD3 may be a useful complementary approach for the disruption of testosterone biosynthesis in the treatment of PCa.