Plasma Exchange in Patients With Myositis due to Immune Checkpoint Inhibitor Therapy

Area of Science:

• Oncology
• Immunology
• Neurology

Background:

• Immune checkpoint inhibitors (ICIs) are crucial cancer therapies.
• Immune-related adverse events (irAEs) can manifest as myositis.
• Myositis can significantly impact patient quality of life.

Observation:

• Two patients developed myositis after ICI treatment (nivolumab and durvalumab).
• Patients presented with progressive muscle weakness and elevated creatine kinase levels.
• Electrophysiology ruled out neuromuscular junction disorders and myasthenia gravis.

Findings:

• Therapeutic plasma exchange (PLEX) was administered to both patients.
• Both patients experienced rapid and significant improvement in muscle strength after PLEX.
• PLEX demonstrated efficacy in treating ICI-induced myositis.

Implications:

• PLEX is a valuable treatment option for immune-related adverse event myositis.
• This approach can be effective even in the absence of myasthenia gravis.
• Early intervention with PLEX may improve outcomes for patients with ICI-associated myositis.