Basic fibroblast growth factor in patients with intermittent claudication: results of a phase I trial

OBJECTIVES This phase I study was designed to evaluate the safety, tolerability and pharmacokinetics of intra-arterial basic fibroblast growth factor (bFGF) in patients with atherosclerotic peripheral arterial disease (PVD) and intermittent claudication. We also assessed the effects of basic fibroblast growth factor (bFGF) on calf blood flow as a measure of biologic activity. BACKGROUND Preclinical studies have shown that bFGF, an angiogenic peptide, promotes collateral development in animal models of myocardial and hind limb ischemia. The safety and efficacy of bFGF in patients is unknown, and early clinical trials are underway in coronary and peripheral arterial disease. METHODS A double-blind, placebo-controlled, dose-escalation trial was conducted in patients with claudication demonstrating ankle/brachial index <0.8. Patients were randomly assigned to placebo (n = 6), 10 μg/kg of bFGF (n = 4), 30 μg/kg of bFGF once (n = 5) and 30 μg/kg of bFGF on two consecutive days (n = 4). Study drug was infused into the femoral artery of the ischemic leg. Detailed safety information including retinal photography for neovascularization were obtained through one year. Calf blood flow was measured with strain gauge plethysmography in the two higher dose treatment groups and in four placebo patients at baseline, one month and three to seven months after treatment. RESULTS Intra-arterial bFGF was safe and well-tolerated. The half-life was 46 ± 21 min. Calf blood flow increased at one month by 66 ± 26% (mean ± SEM) and at six months by 153 ± 51% in bFGF-treated patients (n = 9, p = 0.002). Flow did not change significantly in the placebo group. CONCLUSIONS In this initial randomized, double-blind, placebo-controlled trial in patients with atherosclerotic PVD and claudication, bFGF was well-tolerated. The data suggest a salutary biologic effect, and initiation of phase 2 trials is warranted.