Apabetalone Downregulates Fibrotic, Inflammatory and Calcific Processes in Renal Mesangial Cells and Patients with Renal Impairment.

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-ß1 stimulation by suppressing TGF-ß1-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-ß1 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.

Cognitive Effects of the BET Protein Inhibitor Apabetalone: A Prespecified Montreal Cognitive Assessment Analysis Nested in the BETonMACE Randomized Controlled Trial.

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.

Effect of Apabetalone on Cardiovascular Events in Diabetes, CKD, and Recent Acute Coronary Syndrome: Results from the BETonMACE Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: CKD and type 2 diabetes mellitus interact to increase the risk of major adverse cardiovascular events (i.e., cardiovascular death, nonfatal myocardial infarction, or stroke) and congestive heart failure. A maladaptive epigenetic response may be a cardiovascular risk driver and amenable to modification with apabetalone, a selective modulator of the bromodomain and extraterminal domain transcription system. We examined this question in a prespecified analysis of BETonMACE, a phase 3 trial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: BETonMACE was an event-driven, randomized, double-blind, placebo-controlled trial comparing effects of apabetalone versus placebo on major adverse cardiovascular events and heart failure hospitalizations in 2425 participants with type 2 diabetes and a recent acute coronary syndrome, including 288 participants with CKD with eGFR <60 ml/min per 1.73 m2 at baseline. The primary end point in BETonMACE was the time to the first major adverse cardiovascular event, with a secondary end point of time to hospitalization for heart failure. RESULTS: Median follow-up was 27 months (interquartile range, 20-32 months). In participants with CKD, apabetalone compared with placebo was associated with fewer major adverse cardiovascular events (13 events in 124 patients [11%] versus 35 events in 164 patients [21%]; hazard ratio, 0.50; 95% confidence interval, 0.26 to 0.96) and fewer heart failure-related hospitalizations (three hospitalizations in 124 patients [3%] versus 14 hospitalizations in 164 patients [9%]; hazard ratio, 0.48; 95% confidence interval, 0.26 to 0.86). In the non-CKD group, the corresponding hazard ratio values were 0.96 (95% confidence interval, 0.74 to 1.24) for major adverse cardiovascular events, and 0.76 (95% confidence interval, 0.46 to 1.27) for heart failure-related hospitalization. Interaction of CKD on treatment effect was P=0.03 for major adverse cardiovascular events, and P=0.12 for heart failure-related hospitalization. Participants with CKD showed similar numbers of adverse events, regardless of randomization to apabetalone or placebo (119 [73%] versus 88 [71%] patients), and there were fewer serious adverse events (29% versus 43%; P=0.02) in the apabetalone group. CONCLUSIONS: Apabetalone may reduce the incidence of major adverse cardiovascular events in patients with CKD and type 2 diabetes who have a high burden of cardiovascular disease.

Apabetalone lowers serum alkaline phosphatase and improves cardiovascular risk in patients with cardiovascular disease.

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 < 0.001) after 12-14 weeks and 7.7% (p < 0.001) after 24-26 weeks of apabetalone treatment. In the apabetalone group, a 1-SD reduction in ALP was associated with a HR for MACE of 0.64 (95% CI 0.46-0.90, p = 0.009). CONCLUSIONS: Serum ALP predicts residual cardiovascular risk, independent of hsCRP, established cardiovascular risk factors and CKD, in patients with cardiovascular disease on statin treatment. Apabetalone lowers serum ALP, which was associated with a lower risk of cardiovascular events. Whether the beneficial cardiovascular effects of apabetalone are causally related to ALP reduction remains undetermined.

Apabetalone Mediated Epigenetic Modulation is Associated with Favorable Kidney Function and Alkaline Phosphatase Profile in Patients with Chronic Kidney Disease.

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) <60 mL/min/1.73m2, 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% (p<0.0001 versus baseline) versus -6.3% (p=0.9 versus baseline). The eGFR in the apabetalone group increased by 3.4% (1.7 mL/min/1.73 m2) (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.