Abstract 2152: Long-term Safety and Clinical Efficacy in the Slow- and Moderate-release Polymer-based, Paclitaxel-eluting TAXUS Stent: Final 5-year Results of the TAXUS II Trial
Background: The TAXUS II trial is a phase II dose-finding study of two different formulations of the polymer-based, paclitaxel-eluting TAXUS Express stent (Boston Scientific Corporation, Natick, MA). Through 4-year follow-up, TAXUS II demonstrated that both the slow-release (SR) and moderate-release (MR) TAXUS stents reduce restenosis versus bare metal Express stents (BMS) in patients with de novo, focal, coronary artery lesions without significant safety concerns. The final 5-year data on clinical safety and efficacy will be discussed at the time of presentation.
Methods: TAXUS II is a randomized, double-blind controlled clinical trial conducted at 38 sites comparing the safety and efficacy of TAXUS SR (N=131) and TAXUS MR (N=135) versus BMS (N=270). The primary endpoint was 6-month percent in-stent net volume obstruction as assessed by intravascular ultrasound. Per protocol, clinical follow-up occurred yearly for 5 years post-stenting.
Results: Results have previously been presented through 4 years. Both TAXUS groups have demonstrated sustained clinical efficacy with significant reductions in the rate of target lesion revascularization (TLR) for TAXUS versus BMS (7.2% SR, 3.7% MR, 15.7% BMS, p=0.0004), while cardiac death (1.6% SR, 1.6% MR, 1.5% BMS, p>0.99), total death (5.5% SR, 4.6% MR, 3.7% BMS, p=0.74), and myocardial infarction (MI, 4.7% SR, 5.3% MR, 6.7% BMS, p=0.67) rates remained comparable across groups. From 2 to 4 years, there were no new late stent thromboses (ST) in either TAXUS group versus 1 in BMS, and overall ST rates at 4 years were comparable (2.3%, n=3, SR; 1.5%, n=2, MR; 0.4%, n=1, BMS; poverall=0.20). No statistically significant differences between SR and MR cohorts have been noted for any parameter analyzed. Data from 5 years of clinical follow-up will be available for presentation in November 2007.
Conclusion: Given the current focus on late safety and stent thrombosis, long-term follow-up of randomized trials of drug-eluting stent use has become increasingly important. TAXUS II has demonstrated both safety (death, MI, ST) and efficacy (TLR) of the TAXUS stent through 4 years. Final 5-year clinical data, as pre-specified in the protocol, will be presented and will focus on late safety parameters.