New results from the HARMONEE Japan/US registration trial, which were presented yesterday at the 2017 Transcatheter Cardiovascular Therapeutics (TCT) meeting (29 October – 2 November, Denver, USA), show that the overall incidence of target vessel failure at one year was 7% (lower the original estimated 9%) for the Combo dual therapy stent (OrbusNeich) vs. 4.2% for Xience (Abbott Vascular). This result meant that Combo met the requirement for non-inferiority (p=0.020).
HARMONEE (Harmonized assessment by randomized multicenter study of OrbusNeich’s Combo stent) is a registration study being conducted to demonstrate the effectiveness of the combined endothelial progenitor cell capture and drug-eluting stent (Combo) compared with Xience in patients with ischaemic coronary disease and non-ST-elevation acute coronary syndrome.
Kaplan-Meier curves revealed that target vessel revascularisation events driven by the one-year protocol re-catheterisation were notable in both stent groups, despite the use of fractional flow reserve (FFR) to mitigate such event “spikes”. The target lesion failure odds ratio of Combo vs. imputed bare-metal stent was 0.673 and did not meet the pre-specified assay sensitivity, but the comparison was underpowered due to the low target vessel failure rates (4.2% vs. predicted 9%). Combo was superior to imputed bare metal stent with respect to angiographic in stent (p<0.001) and in segment late loss (p=0.003) at 12 months.
An independent quantitative coronary arteriography core laboratory reported in stent late loss at one year of Combo vs Xience of 0.293mm vs. 0.219mm and in segment late loss of 0.229mm vs. 0.220mm respectively. Additionally, the angiographic in stent restenosis of Combo vs Xience was 1.3% vs 2.6% and in segment restenosis was 2.5% vs 3.9%.
Optical coherence tomography (OCT) at 12 months revealed significantly better healthy tissue strut coverage (thickness >40 micron in patients with normal FFR) with Combo vs Xience (91.56% vs 74.82%; p<0.001). Also, the qualitative appraisal of the neointima showed more homogeneous tissue with Combo vs Xience (81.2% vs 68.8%).
Principal investigator Mitchell Krucoff (Duke University Medical Center and Duke Clinical Research Institute, Durham, USA) comments: “Achieving non-inferiority in target vessel failure compared to the best-in-class current drug-eluting stent, with the addition of superior surrogate measures of site healing by Combo in this randomised study, represents the opening of an exciting new chapter in percutaneous coronary intervention device design targeting enhanced safety and effectiveness for patients with coronary artery disease.”