Evaluation of the correlation of baseline blood pressure (BP) and plasma renin activity (PRA) with bevacizumab (B)-mediated hypertension in patients with early-stage breast cancer

Abstract

602 Background: Although hypertension (HTN) develops in 20–30% of bevacizumab (B)-treated cancer patients, no accurate clinical predictors of B-mediated HTN have been identified. We evaluated baseline blood pressure (BP) and plasma renin activity (PRA) as potential predictors of B-mediated HTN among breast cancer patients enrolled in an adjuvant chemotherapy-B study. Methods: In this phase II study, B was administered concurrently (10 mg/kg IV q2wk x 8) with pegfilgrastim-supported chemotherapy (AC at 60/600 mg/m2 q2wk x4 then nab-paclitaxel at 260 mg/m2 q2wk x4) and continued at 15 mg/kg q3wk thereafter for a total one year of B therapy. The primary endpoint was cardiac safety. A secondary endpoint was the prospective exploration of PRA as a predictor of HTN. Patients with baseline BP >150/100 mmHg were excluded from the study. Peripheral blood for PRA was collected at baseline, week 8, week 16 and every 3 months during B administration. In this preliminary analysis, baseline data was available for 65 of the 80 enrolled patients. Baseline BP and PRA values for those who did and did not develop grade 2–4 HTN were evaluated by Wilcoxon rank sum test. Results: The baseline characteristic medians are: age 45y (27–75), baseline diastolic BP 70 mmHg (52–95), baseline systolic BP 120 mmHg (90–146), and number of B cycles administered 20 (1–21). Twenty-one patients (32%) developed grade 2–4 HTN. Median diastolic and systolic BP among patients with grade 2–4 HTN was 78 and 124 mmHg, respectively, versus 70 and 115.5 mm Hg, respectively, among patients without grade 2–4 HTN (p = 0.0256 and p = 0.0228). There was no significant association between baseline PRA values and the development of grade 2–4 HTN versus not (p = 0.2917). Conclusions: At the time of this preliminary analysis, both baseline diastolic and systolic BP appear to positively predict the development of B-mediated grade 2–4 HTN while baseline PRA does not. Studies exploring the relationship between serial PRAs and the development of HTN for all study participants are ongoing. [Table: see text]