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.