Cabozantinib in Metastatic Chromophobe Renal Cell Carcinoma: A Single-Center Case Series.

Chromophobe renal cell carcinoma (chRCC) is a rare subtype of renal malignancy characterized by distinct biological and molecular features. Although localized disease is often associated with favorable outcomes, metastatic chRCC remains therapeutically challenging because of the limited availability of prospective clinical data and the absence of established treatment standards. Cabozantinib, a multi-target tyrosine kinase inhibitor targeting the vascular endothelial growth factor receptor (VEGFR), mesenchymal epithelial transition (MET), and AXL pathways, has demonstrated clinical activity in advanced renal cell carcinoma (RCC) and emerging efficacy in non-clear cell RCC populations; however, evidence in chromophobe histology remains limited. We report a retrospective single-center case series of five patients with metastatic chRCC treated with cabozantinib at a single oncology center. All patients had undergone prior nephrectomy, and three had received previous systemic therapy. Treatment resulted in disease control in all cases, with a partial response observed in three patients and stable disease in two. Radiologic response was assessed according to the response evaluation criteria in solid tumors (RECIST) version 1.1 criteria. The median progression-free survival was 12 months. Cabozantinib was well tolerated, with anticipated adverse events and no severe treatment-related toxicities. Functional status and symptom control were maintained in most patients during treatment, based on routine clinical assessment. These findings suggest that cabozantinib may represent a clinically meaningful treatment option for selected patients with metastatic chRCC and support its further evaluation in this rare disease subtype.