The activity of cabozantinib in nonclear cell histologies has not been evaluated.
Materials and Methods:
Data were collected across 24 Italian hospitals. Patients were aged 18 years and older with advanced nonclear cell renal cell carcinoma (RCC), with an Eastern Cooperative Oncology Group Performance Status 0 to 2, who had relapsed after previous systemic treatments for metastatic disease. Cabozantinib was administered orally at 60 mg once a day in 28 days cycles. Dose reductions to 40 or 20 mg were made due to toxicity. Adverse events (AEs) were monitored using CTCAE version 4.0.
Seventeen patients were enrolled. Three (18%) patients were diagnosed type I papillary RCC, 9 (53%) type II papillary, 3 (18%) chromophobe, and 2 (11%) with Bellini duct carcinoma. In total, 11 patients started with 60 mg. Six patients started a lower dose of 40 mg. Median progression-free survival was 7.83 months (0.4 to 13.4 mo), while median overall survival was not reached but 1-year overall survival was about 60%. Six patients (35%) experienced a partial response to treatment and 6 patients (35%) showed a stable disease. In the remaining 5 (30%), we observed a progressive disease. Grade 3 and 4 AEs were observed in 41% of patients. Among 20 patients, only 1 (6%) discontinued treatment due to AEs. Asthenia (41%), diarrhea (35%), aminotransferase increasing (35%), mucosal inflammation (35%), hand and foot syndrome (24%), and hypothyroidism (24%) were the most frequently AEs.
Our data showed that, cabozantinib is a active and feasible treatment in patient with nonclear cell RCC.