Immune checkpoint inhibitor-associated myositis and myasthenia gravis overlap: Understanding the diversity in a case series

Area of Science:

• Oncology
• Neurology
• Immunology

Background:

• Immune checkpoint inhibitors (ICIs) enhance anti-tumor immunity by releasing T cell inhibition.
• However, this can lead to immune-related adverse events (irAEs) due to loss of self-tolerance.
• Neuromuscular toxicities are known but less common irAEs associated with ICIs.

Observation:

• This case review focuses on four patients with metastatic cancer.
• These patients developed de-novo neuromuscular complications following ICI treatment.
• The observed complications included myositis and seropositive myasthenia gravis.

Findings:

• The four patients presented with overlapping symptoms of myositis and myasthenia gravis.
• These neuromuscular conditions emerged after the initiation of immune checkpoint inhibitor therapy.
• The development was de-novo, indicating a new onset of these conditions.

Implications:

• This case series highlights a specific pattern of neuromuscular irAEs associated with ICIs.
• Early recognition and diagnosis of myositis and myasthenia gravis are crucial in patients receiving ICIs.
• Understanding these ICI-induced toxicities can inform clinical management and patient monitoring strategies.