Background Apabetalone (RVX-208) is a bromodomain and extraterminal protein inhibitor (BETi) that in phase II trials reduced the relative risk (RR) of major adverse cardiac events (MACE) in patients with cardiovascular disease (CVD) by 44% and in diabetic CVD patients by 57% on top of statins. A phase III trial, BETonMACE, is currently assessing apabetalone’s ability to reduce MACE in statin-treated post-acute coronary syndrome type 2 diabetic CVD patients with low high-density lipoprotein C. The leading cause of MACE is atherosclerosis, driven by dysfunctional lipid metabolism and chronic vascular inflammation (VI). In vitro studies have implicated the BET protein BRD4 as an epigenetic driver of inflammation and atherogenesis, suggesting that BETi may be clinically effective in combating VI. Here, we assessed apabetalone’s ability to regulate inflammation-driven gene expression and cell adhesion in vitro and investigated the mechanism by which apabetalone suppresses expression. The clinical impact of apabetalone on mediators of VI was assessed with proteomic analysis of phase II CVD patient plasma. Results In vitro, apabetalone prevented inflammatory (TNFα, LPS, or IL-1β) induction of key factors that drive endothelial activation, monocyte recruitment, adhesion, and plaque destabilization. BRD4 abundance on inflammatory and adhesion gene promoters and enhancers was reduced by apabetalone. BRD2-4 degradation by MZ-1 also prevented TNFα-induced transcription of monocyte and endothelial cell adhesion molecules and inflammatory mediators, confirming BET-dependent regulation. Transcriptional regulation by apabetalone translated into a reduction in monocyte adhesion to an endothelial monolayer. In a phase II trial, apabetalone treatment reduced the abundance of multiple VI mediators in the plasma of CVD patients (SOMAscan® 1.3 k). These proteins correlate with CVD risk and include adhesion molecules, cytokines, and metalloproteinases. Ingenuity® Pathway Analysis (IPA®) predicted that apabetalone inhibits pro-atherogenic regulators and pathways and prevents disease states arising from leukocyte recruitment. Conclusions Apabetalone suppressed gene expression of VI mediators in monocytes and endothelial cells by inhibiting BET-dependent transcription induced by multiple inflammatory stimuli. In CVD patients, apabetalone treatment reduced circulating levels of VI mediators, an outcome conducive with atherosclerotic plaque stabilization and MACE reduction. Inhibition of inflammatory and adhesion molecule gene expression by apabetalone is predicted to contribute to MACE reduction in the phase III BETonMACE trial. Electronic supplementary material The online version of this article (10.1186/s13148-019-0696-z) contains supplementary material, which is available to authorized users.

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.

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Background: Colorectal cancer, one of the most commonly diagnosed cancers, is now being detected earlier and treatments are improving, which means that patients are living longer. Partnering with Canadian clinicians, patients and researchers, we aimed to determine research priorities for those living with early-stage colorectal cancer in Canada. Methods: We followed the well-established priority-setting partnership outlined by the James Lind Alliance to identify and prioritize unanswered questions about early-stage (i.e., stages I–III) colorectal cancer. The study was conducted from September 2018 to September 2020. We surveyed patients, caregivers and clinicians from across Canada between June 2019 and December 2019. We categorized the responses using thematic analysis to generate a list of unique questions. We conducted an interim prioritization survey from April 2020 to July 2020, with patients, caregivers and clinicians, to determine a shorter list of questions, which was then reviewed at a final meeting (involving patients, caregivers and clinicians) in September 2020. At that meeting, we used a consensus-based process to determine the top 10 priorities. Results: For the initial survey, 370 responses were submitted by 185 individuals; of the 98 individuals who provided demographic information, 44 (45%) were patients, 16 (16%) were caregivers, 7 (7%) were members of an advocacy group, 26 (27%) were health care professionals and 5 (5%) were categorized as “other.” The responses were refined to create a list of 66 unique unanswered questions. Twenty-five respondents answered the interim prioritization survey: 13 patients (52%), 2 caregivers (8%), 3 advocacy group members (12%) and 7 health care professionals (28%). This led to a list of the top 30 questions. The final consensus meeting involved 20 individuals (10 patients [50%], 3 caregivers [15%] and 7 health care professionals [35%]), who agreed to the top 10 research priorities. The priorities covered a range of topics, including screening, treatment, recurrence, management of adverse effects and decision-making. Interpretation: We determined the top research priorities for early-stage colorectal cancer using a collaborative partnership of stake-holders from across Canada. The priorities covered a broad range of topics that could be addressed by future research, including improved screening practices, the role of personalized medicine, the management of adverse effects of treatment, decision-making and prevention of recurrence.