ADVERTISEMENT
Drug-Eluting Stent Solutions
October 2004
How does the TAXUS VI clinical trial fit into the TAXUS Stent clinical trial series?>
The TAXUS VI clinical trial is the most recent of six clinical trials over four years to study the safety and efficacy of Boston Scientific's TAXUS Express® Paclitaxel-Eluting Stent. TAXUS VI was designed to evaluate the safety and efficacy of the moderate-release doses of paclitaxel in longer, more complex lesions.
What is the significance of the sub-population data in this study?
The emphasis on studying high-risk patient types was a key component of TAXUS VI. Twenty-eight percent (124 of 448) of the patients in the trial had long lesions with overlapping stents. The small vessel sub-population consisted of 124 patients (28 percent). And diabetic patients who often present with more diffuse disease involving smaller vessels and longer lesions represented 20 percent (89) of the overall patient population in the study. So, we were dealing with complicated lesions that were predominantly Type C in a wider and more challenging range of patient types than had been previously studied.
Tell us more about the paclitaxel formulation in TAXUS VI.
In TAXUS VI, the stent eluted a bi-phasic moderate release of paclitaxel (1 µg/mm2), with a three-times-higher local drug release than that of the FDA-approved TAXUS Express2 Paclitaxel-Eluting Stent System now in use (33 µg in vivo release from a 3.0 mm x 24 mm stent preclinical model over 30 days vs. 12 µg slow-release formulation). At overlapping stent sites, there may be up to twice the exposure level or six times the local drug release of a single slow-release stent. (This moderate release formulation is an investigational device and is not available for sale.)
What did the TAXUS VI trial results show about MACE and SAT rates?
The big news is that even at higher doses of paclitaxel, and even with a greater variety of challenging lesions and patient types, these safety measures were found to be equivalent to those of prior studies. For instance, MACE* rates were low (16.4 percent at nine months compared with 22.5 percent in the control group). The stent thrombosis rates in the TAXUS group were also low (0.5 percent, or 1/219 patients) compared to the control group (1.3 percent or 3/227 patients).
How about efficacy data? How did it compare with earlier trials?
The TAXUS VI efficacy data were consistent with earlier TAXUS trials. The TAXUS VI outcomes showed reductions in TVR, TLR and binary restenosis similar to earlier trials, but in higher-risk patients. It was particularly exciting to see such positive results with diabetics, who comprise a challenging patient sub-population. The TAXUS VI trial had the longest mean lesion length and the highest-risk patient population of any drug-eluting stent trial to date. There is a remarkable consistency of result from trial to trial in terms of late loss and TLR rate. Deliverability has also been consistent across trials.
What is the significance of this trial for cath labs?
There is no doubt that the patients in this trial are good examples of some of the more complex challenges physicians face today in the real world of coronary artery disease treatment. I think that when the technology becomes approved for us, cath labs will look forward to an increase in these kinds of challenging cases.
The TAXUS Express® Moderate-Release Stent is not approved for sale and the safety and efficacy of this device have not been established. TAXUS and Express are trademarks of Boston Scientific or its affiliates. Copyright © 2004 by Boston Scientific or its affiliates. All rights reserved.
Sponsored by Boston Scientific Corporation.
* Major Adverse Cardiac Events, including death, myocardial infarction (MI; Q-wave and non Q-wave) and TVR.
Target Vessel Revascularization (TVR) = 9.1 percent (compared with 19.4 percent control); Target Lesion Revascularization (TLR) = 6.8 percent (compared with 18.9 percent control); binary restenosis = 12.4 percent (compared with 35.7 percent control).
NULL
