A pilot evaluation of the effect of defibrotide in patients affected by peripheral arterial occlusive disease

This was a random double-blind study versus placebo designed to assess the effectiveness and tolerability of defibrotide in patients with chronic peripheral vascular disease (PVD), Leriche stage II. A total of 20 male outpatients (mean age 58.8 years) were selected and treated with placebo for 2 weeks (run-in period), and then allocated randomly to treatment with defibrotide (200 mg/day, intramuscular, n = 10) or matched placebo (n = 10) for 90 days. Before intake and at 15, 30, 60, and 90 days of treatment, each patient received a Doppler ultrasound examination of the lower limbs, and the residual perfusion index (Winsor) was calculated at rest and immediately after a symptom-limited treadmill test. Absolute walking distance was measured in addition. Blood samples were taken for routine laboratory tests before intake and at 30 and 90 days of treatment. All patients completed the trial without adverse effects; no meaningful alterations of laboratory test returns were detected. Patients receiving defibrotide showed a significant increase of the Winsor index after exercise at 90 days versus basal (mean 0.47 +/- 0.04 vs. 0.43 +/- 0.05, p less than 0.05), and a parallel increase of walking distance (basal 288 +/- 42.3 m vs. 368 +/- 46.6 at 60 days, p less than 0.05, and 407 +/- 64.3 m at 90 days, p less than 0.01). No improvement was seen in the placebo group. These preliminary results suggest that defibrotide may prove beneficial to patients with PVD; further studies are needed to find the most appropriate dosage regime.