Combined alternating sunitinib and bevacizumab in the management of advanced renal cell carcinoma: A phase I/II trial.

Abstract

665 Background: Tyrosine kinase inhibitors remain a corner stone in the management of metastatic clear cell renal cell carcinoma (RCC). The intermittent schedule of sunitinib with 4 weeks on/2 weeks off could result in a rebound angiogenesis and tumor progression in the 2 weeks rest period. We propose the use of bevacizumab to alternate with sunitinib to attain continuous anti-angiogenesis during sunitinib therapy. Methods: This was a phase I/II design. Patients advanced clear cell RCC were recruited. Sunitinib was given as 50 mg daily on 4 weeks on/2 weeks off schedule. Bevacizumab was given on day 29 of each sunitinib cycle. Bevacizumab starting dose was 5 mg/kg and the dose was escalated to 10 mg if no dose limiting toxicity. Primary endpoints were response rate and progression-free survival. Results: Twenty-five patients were recruited. The study was closed prematurely because of poor accrual. No dose limiting toxicity was found on the 5 mg dose level of bevacizumab. One patient achieved complete response and 12 achieved partial response for a response rate of 52%. At a median follow up was 42.2 months (95%, confidence interval (CI) 32.9 to 51.4), the median progression-free survival was 16.5 months (95% CI 4.1-28.8), and the median overall survival was 33.3 months (95% CI 19.4-47.3). Twenty-two patients (88%) had at least one grade 3 or 4 toxicity. The commonest grade 3 or 4 toxicity was thrombocytopenia and lymphopenia each occurring at a rate of 32%, followed by hypertension at a rate of 28% followed by fatigue at a rate of 24%. Conclusions: Continuous angiogenesis blockade by adding bevacizumab to sunitinib 4 weeks on and 2 weeks break regimen in advanced RCC produce significant anti-tumor activity with manageable increased toxicity. Clinical trial information: NCT02919371 .