Role of IN-1233 in the prevention of neointimal hyperplasia after stent placement in a rat artery model

Purpose: To evaluate the efficacy of an activin receptorlike kinase (ALK) 5 inhibitor, IN-1233, for the prevention of neointimal hyperplasia after bare stent placement in a rat common iliac artery (CIA) model. Materials and Methods: All experiments were approved by the committee of animal research. A self-expanding metallic bare stent (2 mm × 6 mm) was inserted into the left CIA of 26 Sprague-Dawley male rats (300360 g) under fluoroscopic guidance. IN-1233 was injected via the intraperitoneal route daily in 13 rats for 8 weeks after stent placement (group A); the other 13 rats underwent stent placement only (group B). Angiography was performed immediately and 4 weeks and 8 weeks after stent placement. Rats were sacrificed at 8 weeks after stent placement, and histologic findings were obtained. The neointimal area (NA), percentage of neointimal hyperplasia (%NH), and neointimal-to-medial area ratio (N/M) were assessed and compared between the two groups. Results: Stent placement was technically successful. In 25 rats, arteries with stent placement were angiographically patent, whereas 1 rat in group B had an occlusion. The NA (0.31 mm ² ± 0.09 vs 0.56 mm ² ± 0.17; P <.001), the %NH (26.16% ± 8.75 vs 44.71% ± 17.75; P <.001) and the N/M (1.93 ± 0.77 vs 4.77 ± 2.26; P <.001) were significantly decreased in group A compared with group B. Conclusions: IN-1233 was shown in this study to be effective for the prevention of neointimal hyperplasia after bare metallic stent placement in a rat CIA model.