Successful rescue therapy with eculizumab for probable tislelizumab-related MMM overlap syndrome with dual positivity for anti-acetylcholine receptor and anti-titin antibodies: a case report and literature review

BackgroundWhile immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, they can trigger diverse immune-related adverse events (irAEs). Among these, ICI-related myocarditis, myositis and myasthenia gravis (MMM) overlap syndrome (ICI-MMM) is a rare but potentially fatal complication.

Conventional immunotherapy often exhibits limited efficacy against ICI-MMM, which is associated with high mortality rates. Thus, there is an urgent need for novel and effective strategies to mitigate its life-threatening outcomes.MethodWe conducted a retrospective analysis of the successful rescue use of eculizumab in a patient with tislelizumab-related MMM overlap syndrome who tested seropositive for both anti-acetylcholine receptor (AChR) and anti-titin antibodies.

We also performed a focused systematic literature review on the use of complement inhibitor therapy for ICI-related myasthenia gravis and its overlap syndrome.ResultA 64-year-old male developed ptosis and tetraparesis two weeks following the second infusion of tislelizumab for lung adenocarcinoma. Serological testing revealed dual positivity for anti-AChR antibody and anti-titin antibody.

Tislelizumab was immediately withdrawn, and the patient was treated with corticosteroids and intravenous immunoglobulin as first-line therapy.