Immune checkpoint inhibitor-associated myocarditis : Case reports and a review of the literature

ICI-induced cardiovascular toxicity: mechanisms and immune reprogramming therapeutic strategies

The advent of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, offering life-saving benefits to tumor patients. However, the utilize of ICI agents is often accompanied by immune-related adverse events (irAEs), among which cardiovascular toxicities have attracted more and more attention. ICI induced cardiovascular toxicities predominantly present as acute myocarditis and chronic atherosclerosis, both of which are driven by excessive immune activation. Reprogramming of T cells and macrophages has been demonstrated as a pivotal factor in the pathogenesis of these complications. Therapeutic strategies targeting glycolysis, fatty acid oxidation, reactive oxygen species (ROS) production and some other key signaling have shown promise in mitigating immune hyperactivation and inflammation. In this review, we explored the intricate mechanisms underlying ICI-induced cardiovascular toxicities and highlighted the protective potential of immune reprogramming. We emphasize the roles of T cell and macrophage reprogramming in the heart and vasculature, showcasing their contributions to both short-term and long-term regulation of cardiovascular health. Ultimately, a deeper understanding of these processes will not only enhance the safety of ICIs but also pave the way for innovative strategies to manage immune-related toxicities in cancers therapy.

Therapeutic agents for steroid-refractory immune checkpoint inhibitor-related myocarditis: a narrative review

Background and Objective

Immune checkpoint inhibitors (ICIs) have become one of the cornerstones of current oncology treatment, and immune checkpoint inhibitor-related myocarditis (IRM) is the most fatal of all immune checkpoint inhibitor-related adverse events (irAEs). Methylprednisolone pulse therapy (500-1,000 mg/day) is the initial treatment for IRM recommended by almost all relevant guidelines. However, subsequent treatment regimens remain unclear for patients who do not respond to methylprednisolone pulse therapy (who are defined as steroid-refractory patients). We propose a potential treatment approach for steroid-refractory IRM.

Methods

The PubMed and the Cochrane Library databases were searched using keywords related to IRM. Relevant English-language articles published from January 2000 to February 2024 were included in this narrative review.

Key Content and Findings

Abatacept is the preferred choice for the treatment of isolated steroid-refractory IRM. For rapidly progressive or interleukin-6 abnormally elevated steroid-refractory IRM, alemtuzumab or tocilizumab/tofacitinib are the preferred therapeutic agents, respectively. For steroid-refractory IRM comorbid with myositis or comorbid with myasthenia gravis, abatacept + ruxolitinib/mycophenolate mofetil (MMF)/intravenous immunoglobulin (IVIG), or MMF + pyridostigmine/IVIG are the preferred therapeutic agents, respectively.

Conclusions

The pathogenesis of steroid-refractory IRM and the treatment regimen remain unclear. A large number of studies need to be conducted to validate or update our proposed treatment approach.

Case Report: Sudden very late-onset near fatal PD1 inhibitor-associated myocarditis with out-of-hospital cardiac arrest after >2.5 years of pembrolizumab treatment

Introduction

Immune checkpoint inhibitors have advanced the outcomes of many different types of cancer. A rare but extraordinarily severe complication of these agents resembles immune checkpoint inhibitor-related myocarditis, which typically occurs within the first few weeks after treatment initiation with a mortality of 25%-50%.

Case report

A 57-year-old woman had uneventfully received pembrolizumab for metastatic non-small cell lung cancer for over 2.5 years and was admitted after an out-of-hospital cardiac arrest due to ventricular fibrillation. After successful cardiopulmonary resuscitation, the initial diagnostic work-up showed elevated cardiac enzymes and a limited left-ventricular ejection fraction, while coronary angiography did not show relevant stenosis. Despite cardiac MRI being unsuggestive of myocarditis, myocardial biopsies were obtained and histologically confirmed anti-PD-1 antibody-associated myocarditis. After the initiation of prednisone at 1 mg/kg body weight, the patient gradually recovered and was discharged three weeks later with markedly improved cardiac function.

Conclusion

This case resembles the first description of a very late onset irMyocarditis, occurring over 2.5 years after the start of treatment. It demonstrates the importance of contemplating that severe immune-related toxicities with a sudden onset clinical presentation may occur even after long uneventful periods of anti-PD-1 immune checkpoint inhibitor treatment. Furthermore, it underlines the critical importance of myocardial biopsies in this setting, especially when cardiac MRI remains inconclusive. Moreover, it demonstrates the necessity and benefits of early immunosuppressive treatment if immune-related myocarditis is considered a differential diagnosis.

Role of Biomarkers in the Management of Immune-Checkpoint Inhibitor-Related Myocarditis

PURPOSE OF REVIEW

Immune checkpoint inhibitor (ICI)-related myocarditis poses a major clinical challenge given its non-specific presentation, rapid progression, and high mortality rate. Here, we review the role of blood-based biomarkers in the clinical management of patients with ICI-related myocarditis.

RECENT FINDINGS

Myocardial injury, its unique pattern, and the co-occurrence with myositis are defining features of ICI-related myocarditis. Non-cardiac biomarkers, specifically creatinine phosphokinase, precedes the symptomatic presentation and is highly sensitive for diagnosing ICI-related myocarditis, making them useful screening biomarkers. Combined elevations in cardiac troponins and non-cardiac biomarkers improve the confidence of an ICI myocarditis diagnosis. High troponin and creatinine phosphokinase levels are strongly associated with severe outcomes. We propose biomarker-based algorithms for the monitoring and diagnosis of ICI-related myocarditis. Biomarkers, such as cardiac troponins and creatine phosphokinase, can be used in combination in the monitoring, diagnosis, and prognostication of patients with ICI-related myocarditis.

Data mining for signal detection of adverse events for taxanes based on the food and drug administration adverse drug events reporting system database

BACKGROUND

This study aimed to mine and compare the positive signals of adverse drug events (ADE) in paclitaxel, docetaxel, and nab-paclitaxel to evaluate the accuracy of current drug package information inserts and enable clinicians to select the appropriate treatment.

RESEARCH DESIGN AND METHODS

ADE data reported from January 2006 to December 2020 were extracted from the Food and Drug Adverse Drug Events Reporting System (FAERS) database, and the reporting odds ratio (ROR) was used to detect the risk signals of the 3 taxanes. The definition relied on system organ class (SOCs) and preferred terms (PTs) by the Medical Dictionary for Regulatory Activities (MedDRA).

RESULTS

A total of 39,163 case reports on paclitaxel, docetaxel and nab-paclitaxel involving 25 different system organ classes (SOCs) were retrieved from the database. The ADE paclitaxel and nab-paclitaxel reports mainly focused on 'general disorders and administration site conditions' and the docetaxel ADE reports focused on 'skin and subcutaneous tissue diseases.' Among the three taxanes, nab-paclitaxel had the highest positive signal for serious adverse events.

CONCLUSIONS

Overall, the most common ADE signals and ADE mapping systems obtained in this study were consistent with the package inserts. However, some inconsistencies were noted. Further research is recommended to confirm some of the strong risk signals for ADEs for taxanes before updating the drug package information inserts.

Electrocardiographic Features of Immune Checkpoint Inhibitor-Associated Myocarditis

Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events including myocarditis, whilst improving cancer-related outcomes. There is thus a clinical need to identify electrocardiographic manifestations of ICI-related myocarditis to guide clinical management. PubMed was searched for clinical studies and case reports describing electrocardiographic changes in patients with ICI-related myocarditis. A total of 6 clinical studies and 79 case reports were included. This revealed a range of presentations for patients on ICIs, including supraventricular arrhythmias, ventricular arrhythmias and heart block, and new changes of ST-T segment unrelated to coronary artery disease, ST-segment elevation or depression and T-wave abnormalities. Several patients showed low voltages in multiple leads and new onset Q-wave development. Patients with ICI-related myocarditis may develop new arrhythmia and ST-T changes, and infrequently low voltages in multiple leads.

Overcoming the cardiac toxicities of cancer therapy immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have led recent advances in the field of cancer immunotherapy improving overall survival in multiple malignancies with abysmal prognoses prior to their introduction. The remarkable efficacy of ICIs is however limited by their potential for systemic and organ specific immune-related adverse events (irAEs), most of which present with mild to moderate symptoms that can resolve spontaneously, with discontinuation of therapy or glucocorticoid therapy. Cardiac irAEs however are potentially fatal. The understanding of autoimmune cardiotoxicity remains limited due to its rareness. In this paper, we provide an updated review of the literature on the pathologic mechanisms, diagnosis, and management of autoimmune cardiotoxicity resulting from ICIs and their combinations and provide perspective on potential strategies and ongoing research developments to prevent and mitigate their occurrence.

Immune Checkpoint Inhibitor-Related Myositis Overlapping With Myocarditis: An Institutional Case Series and a Systematic Review of Literature

Background: Immune checkpoint inhibitor (ICI)-related myositis with myocarditis is a rare but potentially fatal immune-related adverse event. However, its clinical features, response to immunosuppressive treatment, and prognosis remain poorly understood. Here, we describe the clinical course of patients with ICI-related myositis overlapping with myocarditis treated at our institution and a systematic review focusing on the response to immunosuppressive therapy.

Methods: We identified patients who developed ICI-induced myositis with myocarditis and were treated at our hospital using a retrospective chart review of electronic medical records. For the systematic review, studies reporting ICI-induced myositis with myocarditis were identified using the Cochrane Library and PubMed databases.

Results: Of the 625 patients treated with ICIs, four developed myositis with concurrent myocarditis. All the patients received immunosuppressive therapy. We assessed the activity of myocarditis and myositis based on temporal changes in troponin and creatine kinase (CK) levels. In all patients, peak troponin values appeared later than the peak CK values (median, 17 days). The median time from the start of ICI therapy to the peak of troponin and CK levels was 42.5 and 28 days, respectively. In all patients, CK levels decreased rapidly and steadily after the initiation of immunosuppressants. However, troponin levels were unstable and increased. In all patients, CK levels normalized within one month (range, 12–27 days), but troponin levels took several months to normalize (range, 84–161 days). Fourteen cases of ICI-related myositis with myocarditis were included in the systematic review. Of the 14 cases, 12 (86%) had their CK level decreased after the initial steroid treatment, but the troponin level increased and was higher than that before the start of treatment. In addition, the peak troponin values appeared later than the peak CK values (a median of 6.5 days). Eight (89%) of 9 long-term follow-up patients had troponin levels above the normal range even after CK normalization.

Conclusion: In most cases of ICI-related myositis with myocarditis, troponin levels increased after the initial steroid treatment despite decreased CK levels, and exceeded pre-steroid levels. In addition, troponin remained elevated for several months after CK normalized.