An Uncommon Case of Myocarditis Secondary to Durvalumab Plus Tremelimumab

Tumor immunotherapy is an important clinical strategy for the treatment of various solid and hematological malignancies, and its use is on the rise. Immune checkpoint inhibitors (ICIs) are immunotherapies that boost anticancer immune responses by targeting receptors on the surface of T-lymphocytes. Two important ICIs are anti-programmed death ligand-1 (anti-PD-L1) monoclonal antibodies and anti-cytotoxic T-lymphocyte-associated antigen-4 (anti-CTLA-4) monoclonal antibodies. Tremelimumab (anti-CTLA-4) and durvalumab (anti-PD-L1) have been shown to be effective monotherapies. However, their combination has demonstrated effective and encouraging antitumor activity with manageable safety in patients with unresectable hepatocellular carcinoma. We present the case of an 80-year-old male with hepatocellular carcinoma who had undergone drug-eluting bead transarterial chemoembolization (DEB-TACE) on three occasions and had been started on a combination of ICIs, durvalumab, and tremelimumab. He subsequently developed various immune-related adverse effects in different organ systems, including hepatic and cardiovascular complications. Appropriate treatment was administered, but ultimately, he passed away. We aim to discuss the initial evaluation for suspected immune-related adverse events, specifically those related to myocarditis and its various manifestations, prognosis, and treatment.