Polymer-Free Biolimus A9-Coated Stents in the Treatment of De Novo Coronary Lesions: 4- and 12-Month Angiographic Follow-Up and Final 5-Year Clinical Outcomes of the Prospective, Multicenter BioFreedom FIM Clinical Trial

Objectives: The purpose of this study was to evaluate the efficacy and long-term outcomes of a novel polymer/carrier-free drug-coated stent (DCS) in patients with de novo coronary lesions.

Background: The BioFreedom (BFD) DCS incorporates a low-profile, stainless-steel platform, with a surface that has been modified to create a selectively microstructured abluminal surface that allows adhesion and further release of Biolimus A9 (Biosensors Europe SA, Morges, Switzerland).

Methods: A total of 182 patients (183 lesions) were randomized into a 1:1:1 ratio for treatment with BFD "standard dose" (BFD) or BFD "low dose" (BFD-LD) versus first-generation paclitaxel-eluting stents (PES) at 4 sites in Germany.

Results: Baseline and procedural characteristics were well matched. At 4-month angiographic follow-up (Cohort 1, n = 75), in-stent late lumen loss (LLL) was significantly lower with BFD and BFD-LD versus PES (0.08 and 0.12 mm vs. 0.37 mm, respectively; p < 0.0001 for BFD vs. PES, and p = 0.002 for BFD-LD vs. PES). At 12 months (Cohort 2, n = 107), in-stent LLL (primary endpoint) was 0.17 mm in BFD versus 0.35 mm in PES (p = 0.001 for noninferiority; p = 0.11 for superiority); however, the BFD-LD (0.22 mm) did not reach noninferiority (p = 0.21). At 5 years (175 of 182), there were no significant differences in major adverse cardiac events (23.8%, 26.4%, and 20.3%) and clinically indicated target lesion revascularization (10.8%, 13.4%, and 10.2%) for BFD, BFD-LD, and PES, respectively; also, there was no definite/probable stent thrombosis reported.

Conclusions: The BFD, but not the BFD-LD, demonstrated noninferiority versus PES in terms of in-stent LLL, a surrogate of neointimal hyperplasia, at 12-month follow-up. At 5 years, clinical event rates were similar, without occurrence of stent thrombosis in all groups. (BioFreedom FIM Clinical Trial; NCT01172119).