Case Report: Tislelizumab combined with bevacizumab in the treatment of primary malignant pericardial mesothelioma

Background: Primary malignant pericardial mesothelioma (PMPM) is an exceedingly rare and highly malignant tumor that originates in the serosal layer of the pericardium. Currently, there are no specific guidelines for diagnosis and treatment in China and international countries for this disease, so treatment experiences from previous clinical cases are very important in the management of this disease. Case summary: A case involving grade IV bone marrow suppression following pemetrexed in combination with platinum-based chemotherapy has been documented. Subsequently, the patient underwent treatment with tislelizumab and bevacizumab (an immune checkpoint inhibitor combined with a vascular endothelial growth factor inhibitor). After 29.4 months of this treatment, the patient experienced significant relief from symptoms of chest tightness and breathlessness, while the primary tumor lesion remained stable. Imaging assessments indicated stable disease (SD). Throughout the treatment course, no severe adverse reactions resulting in mortality were observed, with only grade II bone marrow suppression and intermittent dry, scaly, and peeling skin on the feet reported. Symptoms improved following symptomatic and supportive interventions. Conclusion: This case report provides suggestive information for the application of tislelizumab combined with bevacizumab in the treatment of pericardial mesothelioma patients, especially those who are unable to tolerate the adverse effects associated with pemetrexed and platinum-based chemotherapy. The limitation is that only one patient is included, the number of cases is small, and there may be uniqueness of individual cases. Consequently, it remains uncertain whether this combination therapy is applicable to all patients with pericardial mesothelioma, nor can we ascertain whether other immune checkpoint inhibitor (ICIs) and vascular endothelial growth factor inhibitors (VEGF inhibitors) exhibit similar efficacy in this context.