Data on gene and protein expression changes induced by apabetalone (RVX-208) in ex vivo treated human whole blood and primary hepatocytes

Selective BET inhibitor RVX-208 ameliorates periodontal inflammation and bone loss

AIM

To determine the effects of RVX-208, a selective bromodomain and extra-terminal domain (BET) inhibitor targeting bromodomain 2 (BD2), on periodontal inflammation and bone loss.

MATERIALS AND METHODS

Macrophage-like cells (RAW264.7) and human gingival epithelial cells were challenged by Porphyromonas gingivalis (Pg) with or without RVX-208. Inflammatory gene expression and cytokine production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. RAW264.7 cells were induced to osteoclast differentiation. After RVX-208 treatment, osteoclast differentiation was evaluated by histology, tartrate-resistant-acid-phosphatase (TRAP) activity and the expression of osteoclast-specific genes. The effect of RVX-208 on osteoclast transcriptome was studied by RNA sequencing. Periodontitis was induced in rats by ligature and local RVX-208 treatment was administered every other day. Alveolar bone loss was measured by micro-computed tomography.

RESULTS

RVX-208 inhibited inflammatory gene expression and cytokine production in Pg-infected cells. Osteoclast differentiation was inhibited by RVX-208, as evidenced by reduced osteoclast number, TRAP activity and osteoclast-specific gene expression. RVX-208 displayed a more selective and less profound suppressive impact on transcriptome compared with pan-BET inhibitor, JQ1. RVX-208 administration prevented the alveolar bone loss in vivo.

CONCLUSIONS

RVX-208 regulated both upstream (inflammatory cytokine production) and downstream (osteoclast differentiation) events that lead to periodontal tissue destruction, suggesting that it may be a promising 'epi-drug' for the prevention of periodontitis.

Reduction in the risk of major adverse cardiovascular events with the BET protein inhibitor apabetalone in patients with recent acute coronary syndrome, type 2 diabetes, and moderate to high likelihood of non-alcoholic fatty liver disease

Background

Nonalcoholic fatty liver disease (NAFLD) is common among patients with type 2 diabetes mellitus (T2DM) and is associated with increased risk for coronary atherosclerosis and acute cardiovascular (CV) events. We employed the validated, non-invasive Angulo NAFLD fibrosis score (FS) in an intervention study in patients with T2DM and recent acute coronary syndrome (ACS) to determine the association of FS with CV risk and treatment response to apabetalone. Apabetalone is a novel selective inhibitor of the second bromodomain of bromodomain and extra-terminal (BET) proteins, epigenetic regulators of gene expression.

Methods

The Phase 3 BETonMACE trial compared apabetalone with placebo in 2,425 patients with T2DM and recent ACS. In this post hoc analysis, we evaluated the impact of apabetalone therapy on CV risk, defined as a composite of major adverse cardiovascular events (MACE: CV death, non-fatal myocardial infarction [MI], or stroke) and hospitalization for heart failure (HHF) in two patient categories of FS that reflect the likelihood of underlying NAFLD. Patients were initially classified into three mutually exclusive categories according to a baseline Angulo FS <-1.455 (F0-F2), -1.455 to 0.675 (indeterminant), and >0.675 (F3-F4), where F0 through F4 connote fibrosis severity none, mild, moderate, severe, and cirrhosis, respectively. The composite of ischemic MACE and HHF in the placebo group was higher in indeterminant and F3-F4 categories compared to the F0-F2 category (17.2% vs 15.0% vs 9.7%). Therefore, for the present analysis, the former two categories were combined into an elevated NAFLD CVD risk group (FS+) that was compared with the F0-F2 group (lower NAFLD risk, FS_0-2).

Results

In 73.7% of patients, FS was elevated and consistent with a moderate-to-high likelihood of advanced liver fibrosis (FS+); 26.3% of patients had a lower FS (FS_0-2). In the placebo group, FS+ patients had a higher incidence of ischemic MACE and HHF (15.4%) than FS_0-2 patients (9.7%). In FS+ patients, addition of apabetalone to standard of care treatment lowered the rate of ischemic MACE compared with placebo (HR = 0.79; 95% CI 0.60-1.05; p=0.10), HHF (HR = 0.53; 95% CI 0.33-0.86; p=0.01), and the composite of ischemic MACE and HHF (HR = 0.76; 95% CI 0.59-0.98; p=0.03). In contrast, there was no apparent benefit of apabetalone in FS_0-2 patients (HR 1.24; 95% CI 0.75-2.07; p=0.40; HR 1.12; 95% CI 0.30-4.14; p=0.87; and HR 1.13; 95% CI 0.69-1.86; p=0.62, respectively). Over a median duration of 26.5 months, FS increased from baseline in both treatment groups, but the increase was smaller in patients assigned to apabetalone than to placebo (p=0.04).

Conclusions

Amongst patients with T2DM, recent ACS, and a moderate-to-high likelihood of advanced liver fibrosis, apabetalone was associated with a significantly lower rate of ischemic MACE and HHF and attenuated the increase in hepatic FS over time.

Apabetalone and hospitalization for heart failure in patients following an acute coronary syndrome: a prespecified analysis of the BETonMACE study

Background

Patients with diabetes and acute coronary syndrome (ACS) are at high risk for subsequent heart failure. Apabetalone is a selective inhibitor of bromodomain and extra-terminal (BET) proteins, epigenetic regulators of gene expression. Preclinical data suggest that apabetalone exerts favorable effects on pathways related to myocardial structure and function and therefore could impact subsequent heart failure events. The effect of apabetalone on heart failure events after an ACS is not currently known.

Methods

The phase 3 BETonMACE trial was a double-blind, randomized comparison of apabetalone versus placebo on the incidence of major adverse cardiovascular events (MACE) in 2425 patients with a recent ACS and diabetes. This prespecified secondary analysis investigated the impact of apabetalone on hospitalization for congestive heart failure, not previously studied.

Results

Patients (age 62 years, 74.4% males, 90% high-intensity statin use, LDL-C 70.3 mg/dL, HDL-C 33.3 mg/dL and HbA1c 7.3%) were followed for an average 26 months. Apabetalone treated patients experienced the nominal finding of a lower rate of first hospitalization for heart failure (2.4% vs. 4.0%, HR 0.59 [95%CI 0.38–0.94], P = 0.03), total number of hospitalizations for heart failure (35 vs. 70, HR 0.47 [95%CI 0.27–0.83], P = 0.01) and the combination of cardiovascular death or hospitalization for heart failure (5.7% vs. 7.8%, HR 0.72 [95%CI 0.53–0.98], P = 0.04).

Conclusion

Apabetalone treatment was associated with fewer hospitalizations for heart failure in patients with type 2 diabetes and recent ACS. Future studies are warranted to define the potential for BET inhibition with apabetalone to prevent heart failure in patients with diabetes and ACS.

Epigenetic Modulation by Apabetalone Counters Cytokine-Driven Acute Phase Response In Vitro, in Mice and in Patients with Cardiovascular Disease

Chronic systemic inflammation contributes to cardiovascular disease (CVD) and correlates with the abundance of acute phase response (APR) proteins in the liver and plasma. Bromodomain and extraterminal (BET) proteins are epigenetic readers that regulate inflammatory gene transcription. We show that BET inhibition by the small molecule apabetalone reduces APR gene and protein expression in human hepatocytes, mouse models, and plasma from CVD patients. Steady-state expression of serum amyloid P, plasminogen activator inhibitor 1, and ceruloplasmin, APR proteins linked to CVD risk, is reduced by apabetalone in cultured hepatocytes and in humanized mouse liver. In cytokine-stimulated hepatocytes, apabetalone reduces the expression of C-reactive protein (CRP), alpha-2-macroglobulin, and serum amyloid P. The latter two are also reduced by apabetalone in the liver of endotoxemic mice. BET knockdown in vitro also counters cytokine-mediated induction of the CRP gene. Mechanistically, apabetalone reduces the cytokine-driven increase in BRD4 BET occupancy at the CRP promoter, confirming that transcription of CRP is BET-dependent. In patients with stable coronary disease, plasma APR proteins CRP, IL-1 receptor antagonist, and fibrinogen γ decrease after apabetalone treatment versus placebo, resulting in a predicted downregulation of the APR pathway and cytokine targets. We conclude that CRP and components of the APR pathway are regulated by BET proteins and that apabetalone counters chronic cytokine signaling in patients.

Effect of Apabetalone Added to Standard Therapy on Major Adverse Cardiovascular Events in Patients With Recent Acute Coronary Syndrome and Type 2 Diabetes: A Randomized Clinical Trial

IMPORTANCE

Bromodomain and extraterminal proteins are epigenetic regulators of gene transcription. Apabetalone is a selective bromodomain and extraterminal protein inhibitor targeting bromodomain 2 and is hypothesized to have potentially favorable effects on pathways related to atherothrombosis. Pooled phase 2 data suggest favorable effects on clinical outcomes.

OBJECTIVE

To test whether apabetalone significantly reduces major adverse cardiovascular events.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled trial, conducted at 190 sites in 13 countries. Patients with an acute coronary syndrome in the preceding 7 to 90 days, type 2 diabetes, and low high-density lipoprotein cholesterol levels were eligible for enrollment, which started November 11, 2015, and ended July 4, 2018, with end of follow-up on July 3, 2019.

INTERVENTIONS

Patients were randomized (1:1) to receive apabetalone, 100 mg orally twice daily (n = 1215), or matching placebo (n = 1210) in addition to standard care.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of time to the first occurrence of cardiovascular death, nonfatal myocardial infarction, or stroke.

RESULTS

Among 2425 patients who were randomized (mean age, 62 years; 618 women [25.6%]), 2320 (95.7%) had full ascertainment of the primary outcome. During a median follow-up of 26.5 months, 274 primary end points occurred: 125 (10.3%) in apabetalone-treated patients and 149 (12.4%) in placebo-treated patients (hazard ratio, 0.82 [95% CI, 0.65-1.04]; P = .11). More patients allocated to apabetalone than placebo discontinued study drug (114 [9.4%] vs 69 [5.7%]) for reasons including elevations of liver enzyme levels (35 [2.9%] vs 11 [0.9%]).

CONCLUSIONS AND RELEVANCE

Among patients with recent acute coronary syndrome, type 2 diabetes, and low high-density lipoprotein cholesterol levels, the selective bromodomain and extraterminal protein inhibitor apabetalone added to standard therapy did not significantly reduce the risk of major adverse cardiovascular events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02586155.

Effect of selective BET protein inhibitor apabetalone on cardiovascular outcomes in patients with acute coronary syndrome and diabetes: Rationale, design, and baseline characteristics of the BETonMACE trial

After an acute coronary syndrome (ACS), patients with diabetes remain at high risk for additional cardiovascular events despite use of current therapies. Bromodomain and extra-terminal (BET) proteins are epigenetic modulators of inflammation, thrombogenesis, and lipoprotein metabolism implicated in atherothrombosis. The BETonMACE trial tests the hypothesis that treatment with apabetalone, a selective BET protein inhibitor, will improve cardiovascular outcomes in patients with diabetes after an ACS. DESIGN: Patients (n = 2425) with ACS in the preceding 7 to 90 days, with type 2 diabetes and low HDL cholesterol (≤40 mg/dl for men, ≤45 mg/dl for women), receiving intensive or maximum-tolerated therapy with atorvastatin or rosuvastatin, were assigned in double-blind fashion to receive apabetalone 100 mg orally twice daily or matching placebo. Baseline characteristics include female sex (25%), myocardial infarction as index ACS event (74%), coronary revascularization for index ACS (80%), treatment with dual anti-platelet therapy (87%) and renin-angiotensin system inhibitors (91%), median LDL cholesterol 65 mg per deciliter, and median HbA1c 7.3%. The primary efficacy measure is time to first occurrence of cardiovascular death, non-fatal myocardial infarction, or stroke. Assumptions include a primary event rate of 7% per annum in the placebo group and median follow-up of 1.5 years. Patients will be followed until at least 250 primary endpoint events have occurred, providing 80% power to detect a 30% reduction in the primary endpoint with apabetalone. SUMMARY: BETonMACE will determine whether the addition of the selective BET protein inhibitor apabetalone to contemporary standard of care for ACS reduces cardiovascular morbidity and mortality in patients with type 2 diabetes. Results are expected in 2019.

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.

Bromodomains: a new target class for drug development

Less than a decade ago, it was shown that bromodomains, acetyl lysine 'reader' modules found in proteins with varied functions, were highly tractable small-molecule targets. This is an unusual property for protein-protein or protein-peptide interaction domains, and it prompted a wave of chemical probe discovery to understand the biological potential of new agents that targeted bromodomains. The original examples, inhibitors of the bromodomain and extra-terminal (BET) class of bromodomains, showed enticing anti-inflammatory and anticancer activities, and several compounds have since advanced to human clinical trials. Here, we review the current state of BET inhibitor biology in relation to clinical development, and we discuss the next wave of bromodomain inhibitors with clinical potential in oncology and non-oncology indications. The lessons learned from BET inhibitor programmes should affect efforts to develop drugs that target non-BET bromodomains and other epigenetic readers.

The Effect of Bromodomain and Extra-Terminal Inhibitor Apabetalone on Attenuated Coronary Atherosclerotic Plaque: Insights from the ASSURE Trial

BACKGROUND

Apabetalone is a selective bromodomain and extra-terminal (BET) inhibitor which modulates lipid and inflammatory pathways implicated in atherosclerosis. The impact of apabetalone on attenuated coronary atherosclerotic plaque (AP), a measure of vulnerability, is unknown.

METHODS

The ApoA-1 Synthesis Stimulation and intravascular Ultrasound for coronary atheroma Regression Evaluation (ASSURE; NCT01067820) study employed serial intravascular ultrasound (IVUS) measures of coronary atheroma in 281 patients treated with apabetalone or placebo for 26 weeks. AP was measured at baseline and follow-up. Factors associated with changes in AP were investigated.

RESULTS

AP was observed in 31 patients (11%) [27 (13.0%) in the apabetalone group and four (5.5%) in the placebo group]. The apabetalone group demonstrated reductions in AP length by - 1 mm [interquartile range (IQR) - 4, 1] (p = 0.03), AP arc by - 37.0° (IQR - 59.2, 8.2) (p = 0.003) and the AP index by - 34.6 mm° (IQR - 52.6, 10.1) (p = 0.003) from baseline. The change in AP index correlated with on-treatment concentration of high-density lipoprotein (HDL) particles (r = - 0.52, p = 0.006), but not HDL cholesterol (r = - 0.11, p = 0.60) or apolipoprotein A-1 (r = - 0.16, p = 0.43). Multivariable analysis revealed that on-treatment concentrations of HDL particles (p = 0.03) and very low-density lipoprotein particles (p = 0.01) were independently associated with changes in AP index.

CONCLUSIONS

Apabetalone favorably modulated ultrasonic measures of plaque vulnerability in the population studied, which may relate to an increase in HDL particle concentrations. The clinical implications are currently being investigated in the phase 3 major adverse cardiac event outcomes trial BETonMACE.

Cholesterol transport system: An integrated cholesterol transport model involved in atherosclerosis

Atherosclerosis, the pathological basis of most cardiovascular disease (CVD), is closely associated with cholesterol accumulation in the arterial intima. Excessive cholesterol is removed by the reverse cholesterol transport (RCT) pathway, representing a major antiatherogenic mechanism. In addition to the RCT, other pathways are required for maintaining the whole-body cholesterol homeostasis. Thus, we propose a working model of integrated cholesterol transport, termed the cholesterol transport system (CTS), to describe body cholesterol metabolism. The novel model not only involves the classical view of RCT but also contains other steps, such as cholesterol absorption in the small intestine, low-density lipoprotein uptake by the liver, and transintestinal cholesterol excretion. Extensive studies have shown that dysfunctional CTS is one of the major causes for hypercholesterolemia and atherosclerosis. Currently, several drugs are available to improve the CTS efficiently. There are also several therapeutic approaches that have entered into clinical trials and shown considerable promise for decreasing the risk of CVD. In recent years, a variety of novel findings reveal the molecular mechanisms for the CTS and its role in the development of atherosclerosis, thereby providing novel insights into the understanding of whole-body cholesterol transport and metabolism. In this review, we summarize the latest advances in this area with an emphasis on the therapeutic potential of targeting the CTS in CVD patients.

Benefit of Apabetalone on Plasma Proteins in Renal Disease

INTRODUCTION

Apabetalone, a small molecule inhibitor, targets epigenetic readers termed BET proteins that contribute to gene dysregulation in human disorders. Apabetalone has in vitro and in vivo anti-inflammatory and antiatherosclerotic properties. In phase 2 clinical trials, this drug reduced the incidence of major adverse cardiac events in patients with cardiovascular disease. Chronic kidney disease is associated with a progressive loss of renal function and a high risk of cardiovascular disease. We studied the impact of apabetalone on the plasma proteome in patients with impaired kidney function.

METHODS

Subjects with stage 4 or 5 chronic kidney disease and matched controls received a single dose of apabetalone. Plasma was collected for pharmacokinetic analysis and for proteomics profiling using the SOMAscan 1.3k platform. Proteomics data were analyzed with Ingenuity Pathway Analysis to identify dysregulated pathways in diseased patients, which were targeted by apabetalone.

RESULTS

At baseline, 169 plasma proteins (adjusted P value <0.05) were differentially enriched in renally impaired patients versus control subjects, including cystatin C and β2 microglobulin, which correlate with renal function. Bioinformatics analysis of the plasma proteome revealed a significant activation of 42 pathways that control immunity and inflammation, oxidative stress, endothelial dysfunction, vascular calcification, and coagulation. At 12 hours postdose, apabetalone countered the activation of pathways associated with renal disease and reduced the abundance of disease markers, including interleukin-6, plasminogen activator inhibitor-1, and osteopontin.

CONCLUSION

These data demonstrated plasma proteome dysregulation in renally impaired patients and the beneficial impact of apabetalone on pathways linked to chronic kidney disease and its cardiovascular complications.

Selective BET Protein Inhibition with Apabetalone and Cardiovascular Events: A Pooled Analysis of Trials in Patients with Coronary Artery Disease

BACKGROUND

Inhibition of bromodomain and extra-terminal (BET) proteins can modulate lipoprotein and inflammatory factors that mediate atherosclerosis. The impact of the BET inhibitor, apabetalone, on cardiovascular events is unknown.

OBJECTIVE

Our objective was to investigate the impact of apabetalone on cardiovascular event rates in a pooled analysis of clinical studies in patients with established coronary artery disease.

METHODS

We conducted a pooled analysis of patients (n = 798) with coronary artery disease who participated in clinical trials (ASSERT, ASSURE, SUSTAIN) that evaluated the impact of 3-6 months of treatment with apabetalone on lipid parameters and coronary atherosclerosis. The incidence of major adverse cardiovascular events (death, myocardial infarction, coronary revascularization, hospitalization for cardiovascular causes) in the treatment groups was evaluated.

RESULTS

At baseline, patients treated with apabetalone were more likely to be Caucasian, have a history of dyslipidemia, and be undertreated with ß-blocker and anti-platelet agents. Treatment with apabetalone produced the following dose-dependent changes compared with placebo: increases in apolipoprotein A-I (apoA-I) of up to 6.7% (P < 0.001), increases in high-density lipoprotein cholesterol (HDL-C) of up to 6.5% (P < 0.001), increases in large HDL particles of up to 23.3% (P < 0.001), and decreases in high-sensitivity C-reactive protein (hsCRP) of - 21.1% (P = 0.04). Apabetalone treatment did not affect atherogenic lipoproteins compared with placebo. Patients treated with apabetalone experienced fewer major adverse cardiovascular events than those treated with placebo (5.9 vs. 10.4%; P = 0.02), a finding that was more prominent in patients with diabetes (5.4 vs. 12.7%; P = 0.02), with baseline HDL-C < 39 mg/dl (5.5 vs. 12.8%; P = 0.01), or with elevated hsCRP levels (5.4 vs. 14.2%; P = 0.02).

CONCLUSION

Pooled analysis of short-term studies demonstrated fewer cardiovascular events among patients treated with the BET protein inhibitor, apabetalone, than among those treated with placebo. BET protein inhibition warrants further investigation as a novel approach to cardiovascular risk reduction.

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.