Immune Checkpoint Inhibitor-induced Myositis

Area of Science:

• Oncology
• Immunology
• Neurology

Background:

• Immune checkpoint inhibitors (ICIs) are vital cancer therapies.
• Myositis is a rare but potentially fatal immune-related adverse event associated with ICIs.
• Combination ICI therapy increases the incidence of myositis compared to monotherapy.

Purpose of the Study:

• To review the clinical presentation, diagnosis, and management of myositis induced by immune checkpoint inhibitors.
• To highlight the association between combination ICI therapy and increased myositis incidence.
• To discuss the potential co-occurrence of myositis with myocarditis and myasthenia gravis.

Main Methods:

• Literature review of immune checkpoint inhibitor-induced myositis.
• Analysis of clinical manifestations, diagnostic criteria, and therapeutic strategies.
• Evaluation of prognostic factors and associated conditions.

Main Results:

• Myositis presents with varying clinical symptoms, sometimes alongside myocarditis or myasthenia gravis, worsening prognosis.
• Diagnosis relies on clinical signs, elevated muscle enzymes, and electromyography; muscle biopsy may be needed.
• High-dose corticosteroids are the primary treatment, with other immunosuppressive therapies for severe cases.

Conclusions:

• Immune checkpoint inhibitor-induced myositis requires prompt recognition and management.
• Combination ICI therapy necessitates heightened vigilance for myositis development.
• Effective treatment strategies involve corticosteroids and potentially other immunosuppressants for severe presentations.