Systemic exposure of sirolimus after coronary stent implantation in patients with de novo coronary lesions: Supralimus-Core® pharmacokinetic study

DynamX sirolimus-eluting Bioadaptor versus the zotarolimus-eluting Resolute Onyx stent in patients with de novo coronary artery lesions: Design and rationale of the multi-center, international, randomized BIODAPTOR-RCT

BACKGROUND

Conventional drug-eluting stents achieve good safety and performance outcomes, but the stents permanently cage the vessel, leading to a non-plateauing rate of clinical events. The DynamX Bioadaptor is designed to reduce these long-term events through unique design features that permit restoring vessel function and physiology through the disengagement of uncaging elements after the resorption of a biodegradable polymer over six months. Promising initial results have been obtained in the DynamX mechanistic study, with excellent safety and effectiveness, positive arterial remodeling, improved vasomotion, compliance, and cyclic pulsatility. We now aim to confirm these findings randomizing the DynamX Bioadaptor against the Resolute Onyx stent.

METHODS

This multi-center, international, randomized single-blinded study is conducted in 34 sites across Europe, Japan, and New Zealand and is divided into the European/New Zealand cohort and the Japanese cohort (which includes an imaging subset). It is designed to randomly assign 444 patients (222 per region) in a 1:1 ratio to either the DynamX Bioadaptor or the Resolute Onyx stent. Furthermore, a pharmacokinetic substudy is conducted in 9 patients enrolled in Japan to assess the pharmacokinetics of sirolimus after implantation of the DynamX Bioadaptor. Study follow-up is scheduled at one, six, and 12 months, and annually thereafter for five years; imaging follow-up includes angiographic, intravascular ultrasound, and optical coherence tomography assessments at 12 months in a subset of patients. The primary endpoint is 12-month target lesion failure.

CONCLUSIONS

This trial will provide valuable insights into the safety and efficacy of this novel bioadaptor when compared to a contemporary drug-eluting stent.

CONDENSED ABSTRACT

The DynamX Sirolimus-Eluting Bioadaptor has unique design features aiming to reduce long-term events after percutaneous coronary intervention by permitting the restoration of vessel function through the freeing of uncaging elements. Promising initial results have been obtained in the DynamX mechanistic study. This trial aims to confirm these findings in a randomized setting. The European/ New Zealand and Japanese cohorts were designed to randomly assign 444 subjects in a 1:1 ratio to either the DynamX Bioadaptor or the Resolute Onyx stent. Furthermore, a pharmacokinetic substudy is conducted in 9 patients enrolled in Japan to assess the pharmacokinetics of sirolimus.

Pharmacokinetic Study of Sirolimus-Eluting BioResorbable Vascular Scaffold System for Treatment of De Novo Native Coronary Lesions: A Sub-Study of MeRes-1 Trial

Background

MeRes100™ (Meril Life Sciences Pvt. Ltd., Vapi, India) is a novel sirolimus-eluting bioresorbable vascular scaffold (BRS). The purpose of this sub-study of MeRes-1 trial is to evaluate the systemic release of sirolimus from MeRes100 BRS implanted for the treatment of de novo native coronary artery lesions.

Methods

The MeRes-1 is a prospective, multicenter, first-in-human trial of sirolimus-eluting MeRes100 BRS. The pharmacokinetic sub-study was conducted at two Indian sites in 10 patients who were implanted with the MeRes100 BRS loaded with sirolimus at a dose of 1.25 µg/mm². Venous blood samples were collected at pre-dose and 12-time points after implantation of the scaffold. Sirolimus concentration was successively analyzed using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry method.

Results

A total of 12 scaffolds were implanted in 10 patients. Non-compartmental analysis demonstrated time to reach peak concentration of sirolimus between 0.5 h to 3 h after scaffold implantation. The peak concentration (C_max) was deduced to be 7.47 ± 2.61 ng/mL, AUC was 436.45 ± 171.24 h·ng/mL, and the t_½ was observed at 98.59 ± 33.58 h. The clearance was 0.66 ± 0.16 L/h and lower limit of quantification was detectable at 14.1 days.

Conclusions

The MeRes-1 pharmacokinetic sub-study confirmed that MeRes100 BRS is safe and tolerable at limited systemic exposure of sirolimus.

Preliminary Evaluation of Clinical and Angiographic Outcomes with Biodegradable Polymer Coated Sirolimus-Eluting Stent in De Novo Coronary Artery Disease: Results of the MANIPAL-FLEX Study

Objective. The objective of the MANIPAL-FLEX study was to evaluate the feasibility, preliminary safety, and efficacy of the Supraflex sirolimus-eluting stent (SES) implantation, in de novo coronary artery disease, using clinical and quantitative coronary angiography (QCA) follow-ups. Methods. This was a prospective, nonrandomized, multicenter, single-arm study that enrolled 189 patients with de novo coronary artery disease who were treated with the Supraflex SES. Of 189 patients enrolled, the first 61 consecutive patients who consented to a 9-month follow-up evaluation by QCA, irrespective of presence of symptoms, were to be followed up with angiography at 9 months. The primary endpoint of the study was target lesion failure (TLF), including cardiac death, myocardial infarction, and target lesion revascularization during 12-month follow-up after the index procedure. Results. The mean age of the study population was 58 ± 11 years, with 51.3% (97/189) of hypertensive patients. Total of 66 lesions, analyzed by offline QCA, showed good scaffolding of the target vessel with in-stent late lumen loss at 9 months of 0.18 ± 0.23 mm. The observed TLF at 30-day, 6-month, and 12-month follow-up were 2 (1.1%), 6 (3.2%), and 10 (5.3%), respectively. Conclusion. This study provides preliminary evidence for the feasibility, safety, and efficacy of the Supraflex sirolimus-eluting stent.

Evaluation of clinical outcomes in patients undergoing dual vessel percutaneous coronary intervention using sirolimus-eluting coronary stent system in India

INTRODUCTION

Coronary artery disease is the most common catastrophic disease in India. The safety and effectiveness of dual vessel sirolimus-eluting stent (SES) implantation (used as an intervention in CAD) is currently unknown in Indian population. The purpose of this study was to investigate one year clinical outcomes of patients with dual vessel coronary artery disease after implantation of the Supralimus-Core SES, in a "real-world" setting.

MATERIALS AND METHODS

We evaluated 60 patients between April-2011 and August-2012, who underwent dual vessel percutaneous coronary intervention (PCI) with the Supralimus-Core SES implantation at the same index procedure. Dual vessels were defined as involvement of two major epicardial vessels (right, left anterior descending, circumflex, or left main coronary arteries) or one major epicardial vessel and a branch (≥2.5 mm in diameter) originating from another major epicardial vessel. The primary endpoint was target lesion failure (TLF) defined as the composite of cardiac death, myocardial infarction (MI), and clinically-driven target lesion revascularization (TLR) at one year. Secondary endpoint included combined (definite, probable and possible) stent thrombosis (ST).

RESULTS

A total of 120 lesions were treated in 60 enrolled patients (mean age 56.0±9.2 y; 80.0% male) with average stent length of 23.1±8.5 mm. Among 60 patients, diabetes, hypertension and hypercholesterolemia were present in 15 (25.0%), 22 (36.7%) and 25 (41.7%) patients respectively. Indications for PCI were unstable angina in 30 (50.0%) patients and stable angina in 11 (18.3%) patients. Overall, 40 (33.3%) lesions were classified as complex (American College of Cardiology/American Heart Association type B2/C). The cumulative TLF rate was 5.0% (n=3) at one year. Cardiac death, MI and clinically-driven TLR occurred in 1 (1.7%), 0 (0%) and 2 (3.3%) patients, respectively at one year follow-up. The Kaplan-Meier curve of the freedom from overall events at one year was 95.0%. According to the Academic Research Consortium definition, there were no events of stent thrombosis during one year.

CONCLUSION

Our study shows that, dual vessel Supralimus-Core SES implantation allows safe and effective treatment with low rates of TLF at one year follow-up in Indian population.

Development of hydrophobized alginate hydrogels for the vessel-simulating flow-through cell and their usage for biorelevant drug-eluting stent testing

The vessel-simulating flow-through cell (vFTC) has been used to examine release and distribution from drug-eluting stents in an in vitro model adapted to the stent placement in vivo. The aim of this study was to examine the effect of the admixture of different hydrophobic additives to the vessel wall simulating hydrogel compartment on release and distribution from model substance-coated stents. Four alginate-based gel formulations containing reversed-phase column microparticles LiChroprep® RP-18 or medium-chain triglycerides in form of preprocessed oil-in-water emulsions Lipofundin® MCT in different concentrations were successfully developed. Alginate and modified gels were characterized regarding the distribution coefficient for the fluorescent model substances, fluorescein and triamterene, and release as well as distribution of model substances from coated stents were investigated in the vFTC. Distribution coefficients for the hydrophobic model substance triamterene and the hydrophobized gel formulations were up to four times higher than for the reference gel. However, comparison of the obtained release profiles yielded no major differences in dissolution and distribution behavior for both fluorescent model substances (fluorescein, triamterene). Comparison of the test results with mathematically modeled data acquired using finite element methods demonstrated a good agreement between modeled data and experimental results indicating that gel hydrophobicity will only influence release in cases of fast releasing stent coatings.