PDGF beta receptor blockade inhibits intimal hyperplasia in the baboon

Background-We have evaluated the use of a mouse/human chimeric anti-platele t-derived growth factor-beta receptor antibody in combination with heparin to inhibit intimal hyperplasia in the saphenous artery of the baboon after balloon angioplasty. Methods and Results The, study evaluated lesion development in sequential i njuries made 28 days apart, Each animal received control treatment after th e first injury and antibody/heparin therapy after the second injury to the contralateral artery. The antibody was administered by bolus intravenous in jections (10 mg/kg) on study days 1, 4, 8, 15, and 22 and heparin coadminis tered by continuous intravenous infusion at a dose of 0.13 mg/kg per hour. Morphometric analysis of tissue sections showed a 53% decrease in intimal a rea after antibody/heparin treatment (P=0.005), corresponding to a 40% decr ease in the intima-to-media ratio (P=0.005), Smooth muscle cell proliferati on in the injured wall, measured at both 4 and 29 days after balloon injury , were similar in the control and antibody/heparin-treated animals. Conclusions-These data suggest that platelet-derived growth factor plays a key role in the development of intimal lesions at sites of acute vascular i njury in the nonhuman primate.