Myocarditis induced by a novel bifunctional PD-1/CTLA-4 combination antibody: a case report and literature review

Combined PD-1/CTLA-4 blockade improves overall survival in advanced cancers but increases the risk of severe myocarditis. Iparomlimab and Tuvonralimab (Qibian®), a novel bifunctional anti-PD-1/CTLA-4 antibody, has recently entered clinical use, though its cardiotoxicity profile remains largely unknown. No myocarditis cases have been formally reported with this regimen. A 61-year-old woman with ovarian cancer developed generalized malaise, dyspnea, and chest tightness after the second cycle of Iparomlimab and Tuvonralimab. Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels and new electrocardiographic abnormalities were detected. Empirical methylprednisolone therapy (2 mg/kg/day) was initiated. Following the exclusion of acute coronary syndrome by angiography, ICI-induced myocarditis was diagnosed based on the patient’s symptoms, elevated troponin, electrocardiographic abnormalities, and applicable international consensus criteria (ESC/ICOS). Treatment was escalated to include high-dose methylprednisolone pulse (1 g/day), intravenous immunoglobulin, and mycophenolate mofetil. The patient stabilized by day 24 and was discharged. Persistent cardiac dysfunction warranted the implantation of a cardioverter-defibrillator and permanent discontinuation of immune checkpoint inhibitors. We report the first documented case of myocarditis linked to the novel bifunctional PD-1/CTLA-4 combination, Iparomlimab and Tuvonralimab. This case highlights that structural drug optimizations do not preclude severe cardiotoxicity. In resource-limited settings lacking advanced imaging, serial high-sensitivity troponin monitoring served as the cornerstone for early detection and guiding management. This experience confirms that favorable outcomes are achievable through vigilant biomarker surveillance and coordinated multidisciplinary care, even without advanced diagnostics.