Refractory right ventricular myocarditis induced by immune checkpoint inhibitor despite therapy cessation and immune suppression

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.

Treatment of Immune Checkpoint Inhibitor-associated Myocarditis

ABSTRACT

Immune checkpoint inhibitors (ICIs) are a form immunotherapy where the negative regulators of host immunity are targeted, thereby leveraging the own immune system. ICIs have significantly improved cancer survival in several advanced malignancies, and there are currently more than 90 different cancer indications for ICIs. Most patients develop immune-related adverse events during ICI therapy. Most are mild, but a small subset of patients will develop severe and potentially fatal immune-related adverse events. A serious cardiovascular complication of ICI therapy is myocarditis. Although the incidence of myocarditis is low, mortality rates of up to 50% have been reported. The mainstay of ICI-associated myocarditis treatment is high-dose corticosteroids. Unfortunately, half of patients with myocarditis do not show clinical improvement after corticosteroid treatment. Also, high doses of corticosteroids may adversely impact cancer outcomes. There is an evidence gap in the optimal second-line treatment strategy. Currently, there is a paradigm shift in second-line treatment taking place from empirical corticosteroid-only strategies to either intensified initial immunosuppression where corticosteroids are combined with another immunosuppressant or targeted therapies directed at the pathophysiology of ICI myocarditis. However, the available evidence to support these novel strategies is limited to observational studies and case reports. The aim of this review is to summarize the literature, guidelines, and future directions on the pharmacological treatment of ICI myocarditis.

Cancer Therapy-Associated Pulmonary Hypertension and Right Ventricular Dysfunction: Etiologies and Prognostic Implications

Advances in cancer therapies have improved oncologic outcomes but can potentially expose patients to risk of cardiovascular toxicity. While left ventricular (LV) dysfunction is a well-known cardiotoxicity of cancer therapy. Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are seen with several cancer therapies, including alkylating agents, tyrosine kinase inhibitors (TKIs), and immunotherapy, and are associated with significant morbidity and mortality. Awareness and recognition of cancer therapy-associated PH and RV dysfunction is critical to identify underlying etiologies and institute the appropriate therapy. However, gaps exist in the current literature on the epidemiology of PH and RV dysfunction in cancer, underlying pathophysiology and optimal management strategies.