Pembrolizumab-induced myasthenia gravis: Two patients' experiences

Area of Science:

• Oncology
• Immunology
• Neurology

Background:

• Checkpoint inhibitors are vital in treating gynecologic malignancies.
• These therapies can induce rare immunotoxicities, distinct from traditional immunotherapy side effects.
• Prompt recognition and management of immunotoxicities are critical for patient outcomes.

Observation:

• Two cases of pembrolizumab-induced myasthenia gravis (MG) are presented.
• Case 1: An 85-year-old woman with vulvar carcinoma experienced severe respiratory failure after two cycles of pembrolizumab.
• Case 2: An 80-year-old woman with endometrial carcinoma developed ocular myasthenia after two cycles of pembrolizumab.

Findings:

• Pembrolizumab can induce a spectrum of myasthenia gravis severity.
• Symptoms ranged from isolated ocular manifestations to life-threatening respiratory failure.
• The cases highlight the variability in clinical presentation of this immunotoxicity.

Implications:

• Early diagnosis of pembrolizumab-induced MG is essential.
• Timely intervention can mitigate symptom severity and improve patient prognosis.
• Awareness of these rare side effects is crucial for clinicians managing gynecologic cancer patients on immunotherapy.