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Epigenetic mechanisms are implicated in transcriptional programs driving chronic kidney disease (CKD). Apabetalone is an orally available inhibitor of bromodomain and extraterminal (BET) proteins, which are epigenetic readers that modulate gene expression. In the phase 3 BETonMACE trial, apabetalone reduced risk of major adverse cardiac events (MACE) by 50% in the CKD subpopulation, indicating favorable effects along the kidney–heart axis. Activation of human renal mesangial cells (HRMCs) to a contractile phenotype that overproduces extracellular matrix (ECM) and inflammatory cytokines, and promotes calcification, frequently accompanies CKD to drive pathology. Here, we show apabetalone downregulated HRMC activation with TGF-β1 stimulation by suppressing TGF-β1-induced α-smooth muscle actin (α-SMA) expression, α-SMA assembly into stress fibers, enhanced contraction, collagen overproduction, and expression of key drivers of fibrosis, inflammation, or calcification including thrombospondin, fibronectin, periostin, SPARC, interleukin 6, and alkaline phosphatase. Lipopolysaccharide-stimulated expression of inflammatory genes IL6, IL1B, and PTGS2 was also suppressed. Transcriptomics confirmed apabetalone affected gene sets of ECM remodeling and integrins. Clinical translation of in vitro results was indicated in CKD patients where a single dose of apabetalone reduced plasma levels of key pro-fibrotic and inflammatory markers, and indicated inhibition of TGF-β1 signaling. While plasma proteins cannot be traced to the kidney alone, anti-fibrotic and anti-inflammatory effects of apabetalone identified in this study are consistent with the observed decrease in cardiovascular risk in CKD patients.

Background: Epigenetic changes may contribute importantly to cognitive decline in late life including Alzheimer’s disease (AD) and vascular dementia (VaD). Bromodomain and extra-terminal (BET) proteins are epigenetic “readers” that may distort normal gene expression and contribute to chronic disorders. Objective: To assess the effects of apabetalone, a small molecule BET protein inhibitor, on cognitive performance of patients 70 years or older participating in a randomized trial of patients at high risk for major cardiovascular events (MACE). Methods: The Montreal Cognitive Assessment (MoCA) was performed on all patients 70 years or older at the time of randomization. 464 participants were randomized to apabetalone or placebo in the cognition sub-study. In a prespecified analysis, participants were assigned to one of three groups: MoCA score≥26 (normal performance), MoCA score 25–22 (mild cognitive impairment), and MoCA score≤21 (dementia). Exposure to apabetalone was equivalent in the treatment groups in each MoCA-defined group. Results: Apabetalone was associated with an increased total MoCA score in participants with baseline MoCA score of≤21 (p = 0.02). There was no significant difference in change from baseline in the treatment groups with higher MoCA scores. In the cognition study, more patients randomized to apabetalone discontinued study drug for adverse effects (11.3% versus 7.9%). Conclusion: In this randomized controlled study, apabetalone was associated with improved cognition as measured by MoCA scores in those with baseline scores of 21 or less. BET protein inhibitors warrant further investigation for late life cognitive disorders.

BACKGROUND AND AIMS: In patients with cardiovascular disease, considerable residual risk remains despite evidence-based secondary prevention measures. Alkaline phosphatase (ALP) has been suggested as a modifiable cardiovascular risk factor. We sought to determine whether cardiovascular risk reduction by the bromodomain and extra-terminal (BET) protein inhibitor apabetalone is associated with the concomitant lowering of serum ALP. METHODS: In a post-hoc analysis of 795 patients with established coronary heart disease and statin treatment, who participated in phase 2 placebo-controlled trials of apabetalone, we determined the effect of assigned treatment for up to 24 weeks on the incidence of major adverse cardiovascular events (MACE) and serum ALP. RESULTS: Baseline ALP (median 72 U/L) predicted MACE (death, non-fatal myocardial infarction, coronary revascularization, or hospitalization for cardiovascular causes), independent of high-sensitivity C-reactive protein (hsCRP), sex, age, race, study, cardiovascular risk factors, chronic kidney disease (CKD), liver function markers and treatment allocation (hazard ratio [HR] per standard deviation [SD] 1.6, 95% CI 1.19-2.16, p = 0.002). Mean placebo-corrected decreases in ALP from baseline were 9.2% (p

Background/Aims: The association between serum alkaline phosphatase (ALP) with adverse cardiovascular outcomes, in Chronic Kidney Disease (CKD) patients has previously been reported and may be a result of increased vascular calcification and inflammation. Here we report, for the first time, the effects of pharmacologic epigenetic modulation on levels of ALP and kidney function via a novel oral small molecule BET inhibitor, apabetalone, in CKD patients. Methods: A post-hoc analysis evaluated patients with estimated glomerular filtration rate (eGFR) 2, who participated in the apabetalone phase 2 randomized controlled trials (SUSTAIN and ASSURE). 48 CKD subjects with a history of cardiovascular disease (CVD) were treated with 100mg twice-daily of 24 and 26 weeks of apabetalone or placebo. ALP and eGFR were measured prior to randomization and at final visits. Results: Patients who received apabetalone (n=35) versus placebo (n=13) over 6 months showed significantly (p=0.02) lowered serum ALP -14.0% (p2) (p=0.04 versus baseline) and decreased by 5.8% (2.9 mL/min/1.73 m2) (p=0.6 versus baseline) in the placebo group. Apabetalone was well tolerated. Conclusion: A post-hoc analysis of CKD subjects from the SUSTAIN and ASSURE randomized controlled trials demonstrated favorable effects of apabetalone on ALP and eGFR, and generated the hypothesis that epigenetic modulation by BET inhibition may potentially offer a novel therapeutic strategy to treat CVD and progressive kidney function loss in CKD patients. This is being examined in the phase III trial BETonMACE.

The epigenetic modifying compound RVX-208 selectively inhibits the second ligand binding domain in BET proteins to increase ApoA-I/HDL production. In recent trials of CVD patients given standard of care and RVX-208 (200mg/d) there was a 55% relative risk reduction of MACE vs. placebo. This reduction is greater than expected from modest increases in ApoA-I/HDL, thus suggesting benefits of RVX-208 beyond lipid effects. Whether added benefits exist was explored by microarray survey of differential gene expression in primary human hepatocytes (PHH) and whole blood (WB). In PHH, RVX-208 downregulated genes within the complement, fibrin clotting, cholesterol biosynthesis, fatty acid biosynthesis, diabetes and acute phase response (APR) pathways. These data guided more focused analyses on the known HDL proteome encoded by 89 genes of which 30 were affected by RVX-208 and many of these were members of the APR or complement pathways. In support of the microarray data, we used RT-PCR and found RVX-208 lowered mRNA encoding complement 3, 4a/4b and 5 by >50% in Huh-7 and HepG2 cells exposed to RVX-208. Consistent with the mRNA data, secretion of these complement proteins were less from the treated cells. Next the cells were exposed to cytokines in order to mimic an inflammatory state thus inducing complement expression. Treatment with RVX-208 blocked this effect by >50%. Furthermore, in Huh-7 cells, RVX-208 repressed both fibrin clotting factors II (prothrombin) and XI (thromboplastin antecedent) consistent with the PHH microarray data thus suggesting an anti-thrombotic effect for RVX-208. To further extend findings in vitro from hepatoma cells, plasma from patients in our clinical trials who received RVX-208 were assayed and found to have decreased levels of both APR and complement proteins. Lastly, microarray studies of WB from healthy donors treated ex-vivo with RVX-208 uncovered differential regulation of anti- and pro-atherogenic gene sets that were activated and suppressed, respectively by RVX-208. In summary, RVX-208, a selective BET inhibitor, affects several pathways involved in CVD including; reverse cholesterol transport, atherogenesis, complement, thrombosis and vascular inflammation that cumulatively may reduce MACE in high risk CVD patients.

The recently completed human trials SUSTAIN and ASSURE (n=499) showed a 55% reduction of major adverse cardiovascular events (MACE) in atherosclerotic patients treated with statins and oral RVX-208 (200 mg/day). RVX-208 increases ApoA-I, the dominant protein of HDL-c, by selectively inhibiting bromodomain extra-terminal proteins (BET) that are epigenetic readers which regulate chromatin function via binding to acetylated histones. Patients given RVX-208 had increased ApoA-I and HDL-c by 10.3% and 7.7%, respectively. Although significant, these increases may account, in part, for lower MACE. Thus, effects of RVX-208 on other biological processes that impacted atherosclerosis were examined. Specifically, biomarkers of vascular inflammation were measured and microarray techniques were used in studying human primary hepatocytes and whole blood. Results in human aortic endothelial cells (HAEC) exposed to RVX-208 showed suppressed VCAM-1 and MCP-1 with an IC50 of 1uM and 10uM, respectively. In U937 macrophages RVX-208 suppressed the pro-inflammatory cytokine IL-6 (IC50 1uM). Primary hepatocytes treated with RVX-208 lead to upregulation of gene sets within processes such as; transcription, translation and chromatin modeling, as previously seen with other BET inhibitors. More importantly RVX-208 down regulated gene sets within the; complement cascade, fibrin clotting, cholesterol and fatty acid synthesis, innate immune system and diabetes mellitus pathways. Any one of these changes, independently or cumulatively, may underlie the observed MACE reduction. Blood treated ex vivo with RVX-208 suppressed gene sets involved in pro-inflammatory signaling of monocytes and neutrophils, monocyte-endothelial cell interactions, extracellular matrix remodeling and Th1/Th2 cell responses. Moreover, RVX-208 affected genes with known roles in atherosclerosis and/or vascular inflammation yielding an overall anti-atherogenic profile. In summary, the orally active selective BET inhibitor RVX-208 significantly lowers MACE in patients with residual CVD risk receiving standard of care therapy including statins. The above results suggest that RVX-208 alters several biological pathways in a cardioprotective manner which may lead to lower MACE.