811P - Clinic and Home Blood Pressure Measurements are Reliable for Guiding Therapy in Patients with Metastatic Renal Cell Carcinoma Receiving Axitinib as First-Line Therapy

Abstract

ABSTRACT Background Axitinib, a potent and selective inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, is approved in the US in patients (pts) with metastatic renal cell carcinoma (mRCC) who failed 1 prior systemic therapy. Blood pressure (BP) increases are commonly observed with axitinib. BP measurements are subject to error and can vary by method employed, eg, home measurements by pts, ambulatory monitoring, and in-clinic assessments. As part of a phase II study evaluating safety and efficacy of axitinib for treatment-naive mRCC, we prospectively characterised and compared BP measurements from clinic, home, and 24-hr ambulatory BP monitoring (ABPM). Methods Clinic BP was obtained at baseline, Days 1 and 15 of the first 2 treatment cycles, and Day 1 of subsequent 28-day cycles. Home BP was obtained by pts twice daily during the treatment period. In a subset of pts, 24-hr ABPM was performed at baseline and Days 4 and 15. Results 213 pts enrolled. Mean age was 61 years; 67% were men. Pooled median progression-free survival was 14.5 months. No pts had uncontrolled hypertension (HTN) at study entry. All-grade HTN occurred in 63% and grade 3 in 29%, with no grade 4 HTN. By 24-hr ABPM, median increases from baseline in systolic BP/diastolic BP (sBP/dBP) were 10/8 mmHg by Day 4, with modest incremental increases by Day 15 and stabilisation thereafter; changes in BP were generally consistent at all clock times of day. dBP outcomes were highly consistent between clinic and home measurements (mean 83 ± 9 vs 83 ± 9 mmHg on Cycle 1 Day 15, n = 200; 84 ± 11 vs 84 ± 10 mmHg on Cycle 3 Day 1, n = 171). Similarly, dBP measurements were consistent between clinic and 24-hr ABPM (mean 84 ± 10 vs 84 ± 9 mmHg on Cycle 1 Day 15, n = 63). Consistent sBP outcomes were also observed across various time points and measurement modalities. Conclusions BP increased early with axitinib and was generally well-managed. 24-hr ABPM suggests there is no best time of day to measure BP; rather, measuring at a consistent time of day in individual pts would provide the most useful data. Results from clinic and home monitoring appear consistent and both could be reliable in measuring BP and guiding axitinib therapy. Disclosure V. Grunwald: Advisory and honoraria: GSK, Pfizer, Roche, Novartis, Bayer. Research grant: Pfizer. M.N. Fishman: Dr Fishman has received research funding, participated in compensated advisory board and promotional presentations from the manufacturer of the study drug. M. Carducci: Pfizer DSMB for unrelated product (compensated). JHU received research funding for conduct of the trial. A. Bair: Employee of and own stock in Pfizer. Y. Chen: Employee of and own stock in Pfizer. S. Kim: Employee of and own stock in Pfizer. B.I. Rini: Consulting and research funding from Pfizer.