Molecular Mechanisms of Desensitization Underlying the Differential Effects of Formyl Peptide Receptor 2 Agonists on Cardiac Structure-Function Post Myocardial Infarction.

Formyl peptide receptor 2 (FPR2) plays an integral role in the transition of macrophages from a pro-inflammatory program to one that is pro-resolving. FPR2-mediated stimulation of resolution post myocardial infarction has demonstrated efficacy in rodent models and is hypothesized to reduce progression into heart failure. FPR2 agonists that promote long-lasting receptor internalization can lead to persistent desensitization and diminished therapeutic benefits. In vitro signaling profiles and propensities for receptor desensitization of two clinically studied FPR2 agonists, namely, BMS-986235 and ACT-389949, were evaluated. In contrast to BMS-986235, pre-stimulation with ACT-389949 led to a decrease in its potency to inhibit cAMP production. Moreover, ACT-389949 displayed greater efficacy for ß-arrestin recruitment, while efficacy of Gi activation was similar for both agonists. Following agonist-promoted FPR2 internalization, effective recycling to the plasma membrane was observed only with BMS-986235. Use of G protein-coupled receptor kinase (GRK) knock-out cells revealed a differential impact of GRK2 versus GRK5/6 on ß-arrestin recruitment and Gi activation promoted by the two FPR2 agonists. In vivo, decreases of granulocytes in circulation were greatly diminished in mice treated with ACT-389949 but not for BMS-986235. With short-term dosing, both compounds induced a pro-resolution polarization state in cardiac monocyte/macrophages post myocardial infarction. By contrast, with long-term dosing, only BMS-986235 preserved the infarct wall thickness and increased left ventricular ejection fraction in a rat model of myocardial infarction. Altogether, the study shows that differences in the desensitization profiles induced by ACT-389949 and BMS-986235 at the molecular level may explain their distinct inflammatory/pro-resolving activities in vivo.

Discovery of BMS-986339, a Pharmacologically Differentiated Farnesoid X Receptor Agonist for the Treatment of Nonalcoholic Steatohepatitis.

While several farnesoid X receptor (FXR) agonists under clinical investigation for the treatment of nonalcoholic steatohepatitis (NASH) have shown beneficial effects, adverse effects such as pruritus and elevation of plasma lipids have limited their clinical efficacy and approvability. Herein, we report the discovery and preclinical evaluation of compound 32 (BMS-986339), a nonbile acid FXR agonist with a pharmacologically distinct profile relative to our previously reported agonist BMS-986318. Compound 32 exhibited potent in vitro and in vivo activation of FXR, albeit with a context-dependent profile that resulted in tissue-selective effects in vivo. To our knowledge, this is the first report that demonstrates differential induction of Fgf15 in the liver and ileum by FXR agonists in vivo. Compound 32 demonstrated robust antifibrotic efficacy despite reduced activation of certain genes in the liver, suggesting that the additional pharmacology of BMS-986318 does not further benefit efficacy, possibly presenting an opportunity for reduced adverse effects. Further evaluation in humans is warranted to validate this hypothesis.

Discovery of BMS-986318, a Potent Nonbile Acid FXR Agonist for the Treatment of Nonalcoholic Steatohepatitis.

Herein we report the discovery and preclinical biological evaluation of 6-(2-(5-cyclopropyl-3-(3,5-dichloropyridin-4-yl)isoxazol-4-yl)-7-azaspiro[3.5]non-1-en-7-yl)-4-(trifluoromethyl)quinoline-2-carboxylic acid, compound 1 (BMS-986318), a nonbile acid farnesoid X receptor (FXR) agonist. Compound 1 exhibits potent in vitro and in vivo activation of FXR, has a suitable ADME profile, and demonstrates efficacy in the mouse bile duct ligation model of liver cholestasis and fibrosis. The overall profile of compound 1 supports its continued evaluation.

Discovery of an Anion-Dependent Farnesyltransferase Inhibitor from a Phenotypic Screen.

By employing a phenotypic screen, a set of compounds, exemplified by 1, were identified which potentiate the ability of histone deacetylase inhibitor vorinostat to reverse HIV latency. Proteome enrichment followed by quantitative mass spectrometric analysis employing a modified analogue of 1 as affinity bait identified farnesyl transferase (FTase) as the primary interacting protein in cell lysates. This ligand-FTase binding interaction was confirmed via X-ray crystallography and temperature dependent fluorescence studies, despite 1 lacking structural and binding similarity to known FTase inhibitors. Although multiple lines of evidence established the binding interaction, these ligands exhibited minimal inhibitory activity in a cell-free biochemical FTase inhibition assay. Subsequent modification of the biochemical assay by increasing anion concentration demonstrated FTase inhibitory activity in this novel class. We propose 1 binds together with the anion in the active site to inhibit farnesyl transferase. Implications for phenotypic screening deconvolution and HIV reactivation are discussed.