Left ventricular thrombus following axitinib plus toripalimab therapy in metastatic clear cell renal cell carcinoma: a case report

Background The combination of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) and programmed cell death protein 1 (PD-1) inhibitors has become a standard first-line treatment for advanced clear cell renal cell carcinoma (ccRCC). However, cardiovascular toxicities associated with this combination require further clinical attention. Here, we report a rare case of left ventricular (LV) thrombus occurring following axitinib plus toripalimab therapy in metastatic ccRCC and discuss its clinical management strategy. Case presentation A 60-year-old woman with stage IV ccRCC (cT2aN1M1) and bilateral pulmonary metastases achieved a partial response after two cycles of axitinib (5 mg twice daily) combined with toripalimab (240 mg every 21 days). After two cycles at month 1.5, Grade 3 immune-related hepatitis developed, requiring discontinuation of both toripalimab and axitinib, followed by prolonged corticosteroid therapy. After four weeks of corticosteroid treatment, liver transaminases improved, prompting the resumption of axitinib monotherapy while corticosteroids were completely tapered off over a total course of five weeks. Three months after starting initial combination therapy, corresponding to approximately two weeks after axitinib resumption, the patient presented with exertional fatigue. Echocardiography revealed a heterogeneous hyperechoic mass in the mid-anterior wall of the left ventricle with reduced left ventricular ejection fraction (46%). Contrast-enhanced computed tomography (CT) further confirmed the presence of an LV thrombus. Axitinib was discontinued, and anticoagulation therapy with nadroparin calcium followed by warfarin was initiated. Complete thrombus resolution was achieved after three months; however, prolonged interruption of antineoplastic therapy was followed by disease progression. Conclusion This case highlights LV thrombus as a complex, multifactorial cardiovascular event occurring during the course of VEGFR-TKI and ICI therapy in advanced ccRCC. Careful cardiovascular monitoring and multidisciplinary management are essential for early recognition and individualized treatment of this potentially serious complication.