Safety and toxicity of cabozantinib monotherapy in patients with advanced renal cell carcinoma: a Russian multicenter observational study

Abstract

Aim. To assess the safety and to analyze an influence of cabozantinib monotherapy toxicity on treatment efficacy in unselected Russian patients with metastatic renal cell carcinoma (mRCC). Materials and methods. Medical data of 92 patients with verified mRCC were included in the study. The median age of the patients was 56 (1979) years, most of them - 60 (65.2%) were of male gender. Twenty five (27.2%) persons had Eastern Cooperative Oncology Group performance status (ECOG PS). At the time of cabozantinib monotherapy start 5 (5.4%) patients had favorable, 54 (58.7%) intermediate, and 33 (35.9%) unfavorable prognosis by International Metastatic Renal Cancer Database Consortium (IMDC) model. Eighty-three (90.2%) patients were pretreated, including 76 (82.6%) patients who previously received anti-angiogenic agents. All patients were administered with cabozantinib monotherapy (60 mg/day); dose adjustment was performed according to the instruction. Results. Adverse events (AEs) were reported in 81 (88.0%) of 92 patients; 30 (32.6%) AEs were grade 34. Toxicity-related dose reduction of cabozantinib was required in 28 (30.4%), treatment interruption in 15 (16.3%), and discontinuation in 2 (2.2%) patients. The most common AEs were hypertension (69 patients, 75.0%), asthenia (47 patients, 51.1%), diarrhea (43 patients, 46.7%), and palmar-plantar erythrodysesthesia (43 patients, 46.7%). The most common severe AEs were: arterial hypertension (17 patients, 18.5%), diarrhea (6 patients, 6.5%), and palmar-plantar erythrodysesthesia (2 patients, 2.2%). The most frequent laboratory abnormalities during therapy were elevated serum transaminases (33 patients, 35.9%), anemia (13 patients, 14.1%), and thrombocytopenia (10 patients, 10.9%). No previously unreported AEs or laboratory abnormalities were observed. There was a significant increase in progression-free survival (hazard ratio 2.5; 95% confidence interval 1.05.9; p=0.046) and overall survival (hazard ratio 3.0; 95% confidence interval 1.28.3; p0.025) in patients with treatment-related arterial hypertension. Conclusion. The observational study confirmed the acceptable safety profile of cabozantinib in the first and subsequent lines of treatment in mRCC patients. No new safety signals were identified. Treatment-related arterial hypertension may be a favorable predictor of survival.