Emerging Therapies for Recurrent Pericarditis: Interleukin-1 inhibitors

Interleukin-1 Blockers for the Treatment of Recurrent Pericarditis: Pathophysiology, Patient-Reported Outcomes, and Perspectives

ABSTRACT

Recurrent pericarditis (RP) is the most troublesome complication of acute pericarditis reflecting an unresolving inflammation of the pericardial sac around the heart and associated with significant morbidity. Recent studies have shown interleukin-1 (IL-1) signaling to be central to the pathophysiology of cases of RP with evidence of activation of systemic inflammation. We herein review the literature and clinical trials discussing the utility of IL-1 blockade for RP. The early experience of IL-1 blockade with anakinra (Kineret) and its favorable safety profile paved the way for the clinical development of rilonacept (Arcalyst) and subsequent approval by the US FDA for RP. In patients with RP who have become colchicine-resistant and glucocorticoid-dependent, IL-1 blockade with rilonacept or anakinra effectively treats recurrences and prevents future flares and significantly improves quality of life.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1

BACKGROUND

An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs).

METHODS

This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment."

RESULTS

Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1β, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome.

CONCLUSION

Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Paradigm Shift in Diagnosis and Targeted Therapy in Recurrent Pericarditis

PURPOSE OF THE REVIEW

We review the pathophysiology, diagnosis, and contemporary treatment for recurrent pericarditis, with focus on interleukin-1 (IL-1) inhibitors.

RECENT FINDINGS

Recurrent pericarditis occurs in about 15-30% of patients who have acute pericarditis. With increased understanding of the autoinflammatory pathophysiology of recurrent pericarditis, IL-1 inhibitors including anakinra, canakinumab, and rilonacept have been applied to this condition with great promise. In particular, the RHAPSODY trial found rilonacept significantly improves pain and inflammation, while also reducing recurrence with few adverse events. The next IL-1 inhibitor on the block for pericarditis, goflikicept, is also discussed. Understanding the role of the inflammasome via the autoinflammatory pathway in pericarditis has led to incorporation of IL-1 inhibitors in the treatment of recurrent pericarditis, with proven efficacy and safety and randomized trials. This will lead to increase uptake of this agent which demonstrated lower rates of recurrence and faster time to resolution.

New Developments in the Management of Recurrent Pericarditis

Recurrent pericarditis is a common and troublesome complication that affects 15%-30% of patients with a previous episode of pericarditis. However, the pathogenesis of these recurrences is not well understood, and most cases remain idiopathic. Recent advances in medical therapy, including the use of colchicine and anti-interleukin-1 agents like anakinra and rilonacept, have suggested an autoinflammatory rather than an autoimmune mechanism for recurrences with an inflammatory phenotype. As a result, a more personalized approach to treatment is now recommended. Patients with an inflammatory phenotype (fever and elevated C-reactive protein level) should receive colchicine and anti-interleukin-1 agents as first-line therapy, whereas those without systemic inflammation should receive low to moderate doses of corticosteroids (eg, prednisone 0.2-0.5 mg/kg/d as an initial dose) and consider azathioprine and intravenous human immunoglobulins in the case of corticosteroid failure. Tapering of corticosteroids should be slow after achieving clinical remission. In this article, we review the new developments in the management of recurrent pericarditis.

Rilonacept and Other Interleukin-1 Inhibitors in the Treatment of Recurrent Pericarditis

Pericarditis is the commonest form of pericardial disease. Unfortunately, despite optimal treatment, approximately 15-30% of patients with acute pericarditis have recurrence. Many of these patients are refractory to colchicine, and become corticosteroid-dependent. Recurrent pericarditis severely impairs quality of life, and is associated with significant morbidity. Inflammasome formation and overproduction of interleukin (IL)-1 have been found to drive the systemic inflammatory response in recurrent autoinflammatory pericarditis. Several IL-1 inhibitors have been evaluated for their usefulness as therapeutic options. Rilonacept is a dimeric fusion protein that functions as a soluble decoy receptor that binds to both IL-1α and IL-1β, thereby inhibiting the IL-1 pathway. It is safe and efficacious in the treatment of recurrent pericarditis in the RHAPSODY II and III trials. Anakinra is a recombinant IL-1 receptor antagonist that blocks the action of circulating IL-1α and IL-1β. It has also been shown to be safe and efficacious in the AIRTRIP and IRAP studies. Canakinumab is a selective human monoclonal antibody against IL-1β, and data on its use in recurrent pericarditis is scarce. Several questions regarding IL-1 inhibitor therapy, such as the duration of treatment and the recommended tapering protocols, as well as their use in special populations like pregnant or lactating women, remain unanswered and need to be addressed in future studies.

Hybrids of carbonic anhydrase and cyclooxygenase inhibitors attenuate cardiac hypoxic inflammatory injuries

Cardiac inflammation is easily accompanied by hypoxia, while hypoxia-induced injury and microenvironmental variations limit the efficacy of common anti-inflammatory drugs. In order to effectively attenuate myocardial injury caused by hypoxic and inflammatory injury, we designed and synthesized a kind of anti-inflammatory compounds by coupling cyclooxygenase (COX) and carbonic anhydrase (CA) inhibitors, and evaluated the activity and their mechanism in vitro and in vivo. It was found that these compounds were structurally stable and had two enzymatic inhibition activities. By inhibiting the activity of overexpressed CA under hypoxia, the acidic microenvironment can be regulated to inhibit the hypoxic injury, in which the pH-dependent primary drug resistance can be overcome to improve the anti-inflammatory effect of the COX inhibitor. Consequently, this study provides a new strategy for the treatment of cardiac inflammation accompanied by hypoxia.

Novel Pathophysiological, Diagnostic and Therapeutic Concepts in Acute and Recurrent Pericarditis

Acute pericarditis is the most frequent pericardial disease characterized by inflammation of the pericardial layers resulting in pain, dyspnea and fatigue. Often limited to an isolated event, up to 30% of patients experience one or more recurrences. There is limited knowledge about the pathophysiology of this disease, possibly due to the limited availability of animal models. More recently, following seminal clinical trials with colchicine and interleukin-1 (IL-1) blockers and a novel murine model of acute pericarditis using zymosan A, it has become clear that the NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome/IL-1 β axis plays a central role in driving acute pericardial inflammation and in sustaining this process during recurrences. Diagnostic management of pericarditis has been implemented with multimodality imaging including echocardiography, cardiac computed tomography, and cardiac magnetic resonance. These imaging modalities provide essential diagnostic and pathogenetic information, and are able to characterize pericardial inflammation, allowing to refine risk stratification and personalize treatment. Recent acquisitions yield relevant implications with regard to the therapeutic management of acute and recurrent pericarditis. Non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine are cornerstone therapies either for acute and recurrent pericarditis. However, the benefits of targeted agents, such as anakinra - a recombinant human IL-1 receptor antagonist - and rilonacept - an IL-1 α /IL-1 β trap, are being increasingly recognized. To this end, phenotyping patients with pericarditis and addressing such therapies to those presenting with auto-inflammatory features (elevated C-reactive protein, sustained pericardial and systemic inflammation, multiple recurrences) is of utmost importance to identify patients who might be more likely to benefit from NLRP3 inflammasome/IL-1 β pathway blockade.

Efficacy of Anakinra in Pericarditis: A Systematic Review

Inflammation of the pericardium is referred to as pericarditis, which can cause sharp chest pain and has a high chance of recurrence even after treatment. This review will explore anakinra, which is an interleukin-1 receptor antagonist, as a potential new treatment for pericarditis. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by searching PubMed and GoogleScholar from the years 2012 to 2022. After applying inclusion and exclusion criteria, thorough screening, and quality appraisal, a total of eleven studies were included in the review; eight case reports and three clinical trials. All studies showed that 100 mg/day of anakinra caused a remarkable improvement in patient outcomes. In addition, the pericarditis resolved quicker and had a lower chance of recurrence in comparison to conventional therapy.

Hypoxia-Activated Prodrugs with Dual COX-2/CA Inhibitory Effects on Attenuating Cardiac Inflammation under Hypoxia

Cardiac inflammation is generally accompanied by hypoxia, while myocardial injury and an abnormal microenvironment caused by hypoxia tend to suppress the efficacy of common anti-inflammatory drugs. To improve the anti-inflammatory effect under hypoxia, a hypoxia-activated prodrug HAP1 consisting of a cyclooxygenase-2 (COX-2) inhibitor Ind and a carbonic anhydrase (CA) inhibitor Ace was synthesized. HAP1 was found to be activated by nitroreductase (NTR) under hypoxia to release two pharmacophores and achieve the combinatory medication intensively at the hypoxic site, better than Ind or Ace alone. When NTR activity was inhibited by Na₂WO₄ under hypoxia, no pharmacophores were found to release from HAP1 without exhibiting its activity. However, the efficacy of the Ind and Ace combination group (I&A) was not affected. Furthermore, HAP1 showed advantages over I&A in vivo not only in improving bioavailability but also in reducing side effects. The HAP approach turns out to inhibit cardiac inflammation efficiently and safely under hypoxia.

Advances in Imaging and Targeted Therapies for Recurrent Pericarditis: A Review

Importance

Pericarditis is the most common form of pericardial disease. Recurrence of pericarditis affects 15% to 30% of patients after the initial episode of pericarditis. Up to 50% of patients with the first recurrence have additional recurrences. These patients often progress to have colchicine-resistant and corticosteroid-dependent disease. Rapidly evolving cardiac magnetic resonance imaging techniques and novel targeted therapies have paved the way for imaging-guided therapy for recurrent pericarditis. However, the optimal application of these recent advances remains unclear.

Observations

A search was conducted using the PubMed and Cochrane databases for English-language studies, management guidelines, meta-analyses, and review articles published until April 2022 on recurrent pericarditis. Following the 2015 European Society of Cardiology guidelines for the diagnosis and management of pericardial diseases, new clinical trials and registry data have emerged that demonstrate the efficacy of interleukin-1 blockers in recurrent pericarditis. In addition, new observational data have come to light supporting the use of cardiac magnetic resonance imaging in the diagnosis, risk stratification, and management of such patients.

Conclusions and Relevance

Advances in imaging and targeted therapies have led to a paradigm shift in the management of recurrent pericarditis. This narrative review summarizes the established and emerging data on the diagnosis and treatment of recurrent pericarditis with special emphasis on the role of cardiac magnetic resonance imaging and interleukin-1 blockers in the current era of tailored therapy for recurrent pericarditis.

Potential Pathophysiological Mechanisms Underlying Multiple Organ Dysfunction in Cytokine Release Syndrome

In recent decades, many serious respiratory infections have broken out all over the world, including SARS-CoV, MERS, and COVID-19. They are characterized by strong infectivity, rapid disease progression, high mortality, and poor prognosis. Excessive immune system activation results in cytokine hypersecretion, which is an important reason for the aggravation of symptoms, and can spread throughout the body leading to systemic multiple organ dysfunction, namely, cytokine release syndrome (CRS). Although many diseases related to CRS have been identified, the mechanism of CRS is rarely mentioned clearly. This review is intended to clarify the pathogenetic mechanism of CRS in the deterioration of related diseases, describe the important signaling pathways and clinical pathophysiological characteristics of CRS, and provide ideas for further research and development of specific drugs for corresponding targets to treat CRS.