Clinical characteristics, treatment and prognosis of pembrolizumab induced myocarditis

Area of Science:

• Oncology
• Immunology
• Cardiology

Background:

• Pembrolizumab is an immune checkpoint inhibitor used in cancer therapy.
• Immune-related adverse events (irAEs) are known complications of pembrolizumab.
• Myocarditis is a rare but potentially fatal irAE associated with pembrolizumab.

Purpose of the Study:

• To investigate the clinical characteristics and patterns of pembrolizumab-induced myocarditis.
• To establish diagnostic and therapeutic references for myocarditis in patients receiving pembrolizumab.

Main Methods:

• A retrospective analysis of clinical reports of pembrolizumab-induced myocarditis up to May 31, 2025.
• Statistical analysis of demographic data, clinical symptoms, diagnostic findings, and treatment outcomes.
• Inclusion of 97 patients diagnosed with pembrolizumab-induced myocarditis.

Main Results:

• The median age of affected patients was 70 years, with 54.6% being male.
• Common symptoms included dyspnea, shortness of breath, and chest pain.
• Myositis and/or myasthenia gravis co-occurred in 43.3% of patients.
• Abnormalities in cardiac biomarkers, ECG, cardiac MRI, and echocardiograms were observed.
• Following pembrolizumab discontinuation and steroid immunotherapy, 72.2% of patients recovered, while 26.8% died.

Conclusions:

• Pembrolizumab-induced myocarditis is a rare, fatal irAE requiring vigilant monitoring.
• Monitoring cardiac biomarkers, ECG, and echocardiograms is crucial during pembrolizumab therapy.
• Cardiac MRI or biopsy aids in confirming the diagnosis of myocarditis.