XIENCE V~(TM) Everolimus-Eluting Coronary Stent System: A Preclinical Assessment

摘要

Background: The XIENCE V~(TM) everolimus-eluting coronary stent system is a second-generation drug-eluting stent designed for safety and efficacy in the interventional treatment of coronary artery disease and in preventing in-stent restenosis. A comprehensive preclinical program was completed to aid in the scientific design and to demonstrate the safety of XIENCE V. Methods: Studies evaluating clinical dose selection, pharmacokinetics, single and overlapping stent safety, polymer safety, and maximum dose (8x everolimus) safety were conducted in the porcine coronary arterial model at 28, 90, 180 days, and 1 and 2 years. Additionally, a subset of studies was conducted in the rabbit iliac arterial model. Results: Morbidity and mortality rates for all preclinical studies were exceptionally low, being less than 1%. The arterial response observed in the clinical dose selection study and in all safety studies was typified by benign neointimal hyperplasia with endothelialization by 28 days. Everolimus was released in a controlled manner for 120 days and remained primarily localized within the stented arterial region, which was evidenced histologically as peristrut fibrin. The temporal presence of peristrut fibrin matched the everolimus-elution profile. Thrombosis, malapposition, medial loss, or other adverse effects were not observed in any preclinical studies. Conclusion: XIENCE V has demonstrated safety via an extremely comprehensive preclinical program published to date for a DES system, with data generated in two species to 2 years. The preclinical data, along with the SPIRIT clinical trial data, demonstrate the excellent safety and potential efficacy profile of XIENCE V.