Biodegradable Polymer-Based Sirolimus-Eluting Stents With Differing Elution and Absorption Kinetics

Background Whether the rate of drug elution and polymer absorption affects clinical outcomes of biodegradable polymer-based drug-eluting stents (DES) is unknown. The widely used polylactide polymer-based Excel stent (JW Medical, Weihai, China) elutes sirolimus within 180 days, and the polylactide polymer is completely absorbed within 6 to 9 months. In contrast, the poly-lactide-co-glycolide polymer-based BuMA stent (Sino Medical, Tianjin, China) elutes sirolimus within 30 days, and the poly-lactide-co-glycolide polymer is completely absorbed within 3 months. Thus, both metallic DES elute sirolimus, isolating major differences to the polymer and elution kinetics. Objectives The goal of this study was to compare the safety and effectiveness between the BuMA sirolimus-eluting stent (SES) and Excel SES in an “all-comers” population. Methods PANDA III was a multicenter trial with few exclusion criteria, powered for sequential noninferiority and superiority testing. The primary endpoint was 1-year target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization. Results Between December 2013 and August 2014, 2,348 patients were randomly assigned to treatment with BuMA (n = 1,174) or Excel SES (n = 1,174). The 1-year primary endpoint of TLF occurred in 6.4% of patients in each group (difference: 0.06%; 95% confidence interval: −1.93% to 2.04%; pnoninferiority = 0.0003; psuperiority = 0.95). There were no significant between-group differences in any of the secondary endpoints other than the incidence of definite/probable stent thrombosis, which occurred less frequently with the BuMA stent (0.5% vs. 1.3%; log-rank p = 0.048). Conclusions The BuMA SES was demonstrated to be noninferior to the Excel SES for 1-year TLF, with a lower incidence of stent thrombosis. (Comparison of BuMA eG Based BioDegradable Polymer Stent With EXCEL Biodegradable Polymer Sirolimus-eluting Stent in “Real-World” Practice [PANDA-III]; NCT02017275 )