Olympia: Taxus Liberte Performed Well in High-Risk Groups
Consistency of data in high-risk patients encouraging.
Phase-1 and phase-3 data from the Olympia registry of the Taxus Liberte paclitaxel-eluting stent (Boston Scientific) indicate low rates of cardiac events in high-risk subgroups.
According to data presented by Martyn Thomas, MD, of King’s College Hospital of London, 19 of 529 (3.7%) patients enrolled in the phase-1 study had a Liberte stent-related cardiac event at 12 months of evaluation. There were 13 deaths (2.5%), eight cardiac-related, as well as seven myocardial infarctions and 10 reinterventions.
Phase-3 data at six months were similar in 2,066 patients (Figure). Phase 3 may eventually enroll up to 28,000 patients, Thomas said.
High-risk subgroups
Patients in phase 3 represent a “more difficult patient population compared with phase 1 in terms of lesions,” Thomas said. Patients in phase 3 had a higher incidence of multivessel disease (59.3% vs. 49.1%, respectively), and they were slightly older than patients in phase 1: 64.1 ± 11.1 years vs. 58.3 ± 11.2 years, respectively.
In an evaluation of 517 high-risk patients in phase 1, the overall rate of cardiac events was 3.7%, Thomas said. Rates were marginally higher among patients with diabetes (4.3%) (n = 258) and in patients requiring multiple stents (3.8%) (n = 157).
Incidence of cardiac events was 3% among the 1,909 patients considered high risk in the phase 3 population.
Cardiac event rates were 3.7% among the 766 patients with small vessels, 3.4% among the 291 patients with long lesions, 5.4% among the 613 patients requiring multiple stents, and 4% among the 594 patients with diabetes.
Design questions
Jacques Krolen, MD, PhD, of Catharina Hospital, Eindhoven, The Netherlands, raised doubts about the use of registries for evaluating outcomes with the Taxus Liberte drug-eluting stent.
Registries are observational by nature, Krolen said on Wednesday.
Although registries present a heterogeneous population, evaluation is retrospective and patient monitoring is variable, he said. Any analysis of patients is obfuscated by the subjective nature of lesion characterization, as well as by the variability among institutions and investigators, he said.
Despite these problems, the data indicate low rates of Liberte-related cardiac events in a “real world setting,” Krolen said, adding that the consistency of data in high-risk subgroups was encouraging.
The phase-3 data showing more cardiac events in high-risk subgroups compared with the phase-1 data, even at six months, “appear to be more realistic,” Krolen said.
The Taxus Liberte has improved deliverability compared to its forerunner, the Taxus Express drug-eluting stent. Whereas the Express employs alternating macro- and microelements, the Liberte uses uniform, repeating geometry.