ABT-578-eluting stents. The promising successor of sirolimus- and paclitaxel-eluting stent concepts?

ABT-578 is a new synthetic analog of rapamycin, designed to inhibit smooth muscle cell proliferation-a key contributor to restenosis-by blocking the function of the mTOR cell cycle regulatory protein. Given these pharmacodynamics, ABT-578 was considered beneficial for intracoronary delivery to arrest the process responsible for neointimal hyperplasia after angioplasty and stenting. Consequently, the ABT-578-eluting ENDEAVOR stent system has been created, representing a potential new alternative for treating patients with coronary heart disease. In order to evaluate safety, feasibility and efficacy of this stent design, the ENDEAVOR clinical program has been started, including three randomized clinical trials. ENDEAVOR I is the first-in-man trial including 100 patients with native de novo coronary lesions. The 4-month follow-up data, recently presented, demonstrated safety and feasibility of this new drug-eluting stent (DES) concept with a 4-month MACE (major adverse cardiac events) rate of 2.0%. In order to evaluate this stent system in a larger patient population as well as more complex lesion subsets, the multicenter study ENDEAVOR II has been started including a total of 1,200 patients. The enrollment of this study was completed in January 2004. The aim of the US multicenter study ENDEAVOR III is a head-to-head comparison of the ENDEAVOR ABT-578-eluting stent system with the already approved sirolimus-eluting Cypher stent in 369 patients. If the results of both pivotal studies ENDEAVOR II and III confirm the efficacy of the ENDEAVOR stent design observed so far, the ENDEAVOR stent will be established as a new and promising contender in the field of DES.