Cost-effectiveness of Canakinumab for Prevention of Recurrent Cardiovascular Events

Atherothrombosis Prevention and Treatment with Anti-interleukin-1 Agents

PURPOSE OF REVIEW

Despite major advances in terms of prevention, diagnosis, risk-stratification, management and rehabilitation, atherosclerosis and atherothrombosis continue to have major morbidity and mortality implications worldwide. Since the unraveling of the pivotal role of inflammation in atherothrombosis pathophysiology, several focused treatments have been proposed with the ultimate goal of preventing or treating myocardial infarction, stroke, and peripheral artery disease. In particular, given the centrality of interleukin-1 (IL-1), targeted anti-IL-1 agents have attracted substantial attention and efforts. Yet, uncertainty persists on the real risk-benefit and cost-benefit balance of anti-IL-1 agents in patients with or at risk of atherothrombosis.

RECENT FINDINGS

Several trials have been recently completed on atherothrombosis prevention and treatment with anti-IL-1 agents, ranging, for instance, from the large Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS) trial to the series of translational studies conducted within the Virginia Commonwealth University-Anakinra Remodeling Trial (VCU-ART) platform. In light of the present scoping umbrella review, it appears evident that anti-IL-1 agents can reduce systemic inflammation and improve surrogate markers of cardiac and vascular function, with potential benefits on the risk of new/worsening heart failure. One trial suggested an increased risk of major adverse events with anti-interleukin-1 agents, possibly due to a rebound phenomenon, but this was based on a post-hoc analysis of a small number of events, and it was not supported by all other pertinent trials. The CANTOS study showed a potential hazard due to an increased risk of fatal infections, but the effect size was rather small. In addition, cost issues limit the foreseeable scope of these treatment strategies in unselected patients, calling instead for more refined prescribing. The evidence base on the risk-benefit and cost-benefit profile of anti-IL-1 agents for atherothrombosis prevention and treatment has expanded substantially in the last decade. While largely dominated by the landmark CANTOS trial, effect estimates also including the VCU-ART trials suggest complex short- and long-term effects which may prove favorable in carefully selected patients with acute or chronically sustained inflammation. Conversely, more liberal use appears less promising, and further studies with currently available agents or novel ones are eagerly needed to better define their role in the era of precision molecular medicine.

Does low-density lipoprotein cholesterol induce inflammation? If so, does it matter? Current insights and future perspectives for novel therapies

BACKGROUND

Dyslipidemia and inflammation are closely interrelated contributors in the pathogenesis of atherosclerosis. Disorders of lipid metabolism initiate an inflammatory and immune-mediated response in atherosclerosis, while low-density lipoprotein cholesterol (LDL-C) lowering has possible pleiotropic anti-inflammatory effects that extend beyond lipid lowering.

MAIN TEXT

Activation of the immune system/inflammasome destabilizes the plaque, which makes it vulnerable to rupture, resulting in major adverse cardiac events (MACE). The activated immune system potentially accelerates atherosclerosis, and atherosclerosis activates the immune system, creating a vicious circle. LDL-C enhances inflammation, which can be measured through multiple parameters like high-sensitivity C-reactive protein (hsCRP). However, multiple studies have shown that CRP is a marker of residual risk and not, itself, a causal factor. Recently, anti-inflammatory therapy has been shown to decelerate atherosclerosis, resulting in fewer MACE. Nevertheless, an important side effect of anti-inflammatory therapy is the potential for increased infection risk, stressing the importance of only targeting patients with high residual inflammatory risk. Multiple (auto-)inflammatory diseases are potentially related to/influenced by LDL-C through inflammasome activation.

CONCLUSIONS

Research suggests that LDL-C induces inflammation; inflammation is of proven importance in atherosclerotic disease progression; anti-inflammatory therapies yield promise in lowering (cardiovascular) disease risk, especially in selected patients with high (remaining) inflammatory risk; and intriguing new anti-inflammatory developments, for example, in nucleotide-binding leucine-rich repeat-containing pyrine receptor inflammasome targeting, are currently underway, including novel pathway interventions such as immune cell targeting and epigenetic interference. Long-term safety should be carefully monitored for these new strategies and cost-effectiveness carefully evaluated.

Anticytokine Immune Therapy and Atherothrombotic Cardiovascular Risk

Accumulating observations in humans and animals indicate that inflammation plays a key role in atherosclerosis development and subsequent complications. Moreover, the use of loss- or gain-of-function genetically modified, atherosclerosis-prone mice has provided strong experimental evidence for a causal role of innate and adaptive immunity in atherosclerosis and has revealed the pathogenic activity of proinflammatory cytokines, including TNF (tumor necrosis factor)-α, IL (interleukin)-1β, IL-6, and IL-18, and the atheroprotective effect of anti-inflammatory cytokines, including IL-10 and TGF-β. For the past 15 years, treatments using monoclonal antibodies specifically targeting cytokines, commonly referred as biological therapies, have transformed the treatment of chronic inflammatory diseases, such as rheumatoid arthritis or psoriasis, both conditions associated with increased cardiovascular risk. Analyzing the impact of anticytokine therapies on the cardiovascular outcomes of patients with chronic inflammatory diseases provides insight into the clinical relevance of experimental data on the role of inflammation in atherothrombotic cardiovascular diseases. CANTOS (Canakinumab Antiinflammatory Thrombosis Outcome Study) provided the first evidence that targeting inflammation in humans with atherosclerosis could improve clinical outcomes. Treatment with the anti-IL-1β antibody canakinumab significantly reduced recurrent cardiovascular events in individuals with stable coronary artery disease well-treated with standard-of-care measures. Other clinical studies support the protective effects of treatment with anti-TNF-α and anti-IL-6 receptor monoclonal antibodies on cardiovascular risk. Blockade of the IL-23/IL-17 axis, however, warrants caution as a cardiovascular intervention. Targeting this pathway has improved psoriasis but may augment cardiovascular risk in certain patients. Thus, careful consideration of the cardiovascular risk profile may influence the choice of the most appropriate treatment for patients with chronic inflammatory diseases.Visual Overview: An online visual overview is available for this article.

Leveraging Signaling Pathways to Treat Heart Failure With Reduced Ejection Fraction

Advances in the treatment of heart failure with reduced ejection fraction due to systolic dysfunction are engaging an ever-expanding compendium of molecular signaling targets. Well established approaches modifying hemodynamics and cell biology by neurohumoral receptor blockade are evolving, exploring the role and impact of modulating intracellular signaling pathways with more direct myocardial effects. Even well-tread avenues are being reconsidered with new insights into the signaling engaged and thus opportunity to treat underlying myocardial disease. This review explores therapies that have proven successful, those that have not, those that are moving into the clinic but whose utility remains to be confirmed, and those that remain in the experimental realm. The emphasis is on signaling pathways that are tractable for therapeutic manipulation. Of the approaches yet to be tested in humans, we chose those with a well-established experimental history, where clinical translation may be around the corner. The breadth of opportunities bodes well for the next generation of heart failure therapeutics.

Potential Therapeutic Value of Interleukin 1b-targeted Strategies in Atherosclerotic Cardiovascular Disease

Clinical trials have unequivocally shown that cholesterol-lowering drugs decrease the risk of atherosclerotic cardiovascular disease in an exceptionally wide range of individuals. Yet, even when treated optimally according to current standards, many individuals still experience life-threatening ischemic events. Emerging experimental and clinical evidence strongly suggests that persistent inflammation is a major driver of this residual risk, which has opened the door to the application of anti-inflammatory drugs for cardiovascular disease prevention. Here, we review our current knowledge of the biology of interleukin-1β, a key regulator of inflammation in atherosclerotic plaque and the target of the first clinical trial to demonstrate that an anti-inflammatory drug can effectively reduce cardiovascular risk. We discuss the challenges faced by interleukin-1β inhibitors and other anti-inflammatory compounds in their translation to the clinical scenario, and identify other potential targets within this signaling pathway that hold promise in the cardiovascular setting.

Could ornithine supplementation be beneficial to prevent the formation of pro-atherogenic carbamylated low-density lipoprotein (c-LDL) particles?

Carbamylation (or carbamoylation) is a non-enzymatic post-translational modification process of lysine residues and protein N-termini, which occurs throughout the lifespan of both various plasma proteins and low-density lipoprotein (LDL) particles. Carbamylation results from the binding of isocyanates spontaneously derived from high levels of blood urea, environmental pollutants, nutritional sources and leads to the formation of potentially atherogenic carbamylated-LDL (c-LDL) particles. The carbamylation of LDL apolipoproteins is associated unfavorable downstream effects. Ornithine is a non-proteinogenic amino acid, which plays a central role at the urea cycle function. The primary use of ornithine in supplements is to support athletic performance, liver function and wound recovery. Ornithine is structurally highly similar to lysine, and is only one carbon atom shorter in its side-chain. Therefore, we hypothesize that supplemented ornithine could compete with ε-amino groups of lysine residues found in apolipoproteins of native LDL particles in their binding to isocyanates and decrease c-LDL formation. This issue still remains unresolved in current literature and needs to be elucidated in experimental studies.