Efficacy and safety data from patients with advanced renal cell cancer treated with tivozanib hydrochloride after progression on sorafenib.

364 Background: Tivozanib hydrochloride (tivozanib) is a potent, selective, tyrosine kinase inhibitor of all three vascular endothelial growth factor receptors, with a long half-life and has shown superior efficacy, measured as progression-free survival (PFS), as first-line, targeted therapy vs. sorafenib in a phase III trial (TIVO-1) in patients with advanced renal cell carcinoma (J Clin Oncol2012;30[suppl]:Abstract 4501). Patients who progressed (PD) on sorafenib could receive tivozanib in an open-label, prospective multicenter extension study of TIVO-1. We report preliminary efficacy and safety data for patients who had PD on sorafenib and subsequently received tivozanib in this extension study. METHODS Patients with PD on sorafenib, per RECIST version 1.0, were eligible to receive tivozanib dosed at 1.5 mg/day PO for 3 weeks followed by a 1-week rest, in repeated 4-week cycles, until PD or unacceptable toxicity. Patients were to have been no more than 4 weeks from last dose of sorafenib until initiation of tivozanib, and have an ECOG performance status of ≤2. Dose adjustments were performed as previously reported. Objectives included assessing objective response rate (ORR), duration of response, PFS for tivozanib following PD on sorafenib, and overall survival. RESULTS As of January 20, 2012, 127 patients (72.4% male) were evaluable for response. Median age was 59.0 years (range: 23-85 years). ORR was 7.9% (95% CI 3.8-14.0%; partial response [PR]=7.9%; stable disease [SD]=65.4%; PD=18.9%), and 71.3% of patients showed tumor shrinkage. Median duration of PR was 11.1 months (95% CI ≥7.5 months). Median duration of SD was 12.7 months (95% CI ≥7.4 months). Median PFS was 5.6 months (95% CI 5.4-9.1 months). Median OS was not yet reached. Most commonly reported treatment-emergent adverse events (all grades/Grade ≥3) were hypertension (22.4%/10.2%), asthenia (11.0%/3.1%), fatigue (11.0%/3.9%), palmar-plantar erythrodysesthesia (11.0%/1.6%), and diarrhea (10.2%/1.6%). CONCLUSIONS Tivozanib has anti-tumor activity after PD on sorafenib. The adverse-event profile of tivozanib after sorafenib is similar to that observed in TIVO-1. CLINICAL TRIAL INFORMATION NCT01076010.