Poster U9 - Examination of Drug Transfer from Commercial Drug-Coated Balloons to the Arterial Wall

Introduction: A focus point in studying the treatment of vascular diseases is the drug transfer from drug-coated devices to the arterial wall. Devices such as, drug-coated balloons (DCBs) and drug-eluting stents (DES) represent devices used to reduce restenosis rate and improve the long-term outcome of patients. Both devices deliver antiproliferative drugs, primarily Paclitaxel (PTX) and Sirolimus (SIR), to the artery, however, each has a distinct method of doing so. DES use a polymeric coating allowing for a controlled release of the drug over a long period of time. In contrast, DCBs rely on an excipient-drug coating to aid in a quick release and the retention of the drug onto the arterial wall. The efficiency in which the process occurs can influence the clinical outcome of the DCB. Therefore, the goal of this study was to examine the acute drug transfer efficiency of three commercially available DCBs.

Materials and

Methods: The transfer of the PTX coating of three commercially available DCBs (Lutonix: BD, NJ; IN.PACT Admiral: Medtronic, CA; Stellarex: Spectranetics, CO) was evaluated using a validated bench-top system using harvested porcine carotid arteries. Each balloon was deployed once in a single artery using the manufacturers’ recommended delivery parameters for two minutes. The arteries were then placed in a closed system flow-circuit bioreactor for a designated time point of 15 minutes, 1 hour, or 24 hours (n=3 per time point per DCB). The arteries were subjected to a pulsatile flow condition using a culture medium. Following the assigned run-time, the treated arteries were removed, and the arterial drug levels (pharmacokinetics) were measured using liquid chromatography-mass spectrometry. The percent of total PTX transferred from the DCB to the artery was calculated and data is expressed as mean ± standard deviation.

Results, Conclusions, and Discussions: The percent of PTX transferred from the DCB to the artery was calculated for each sample and averaged for each time point. For the Lutonix DCB, the drug transfer percent was 0.53±0.59% for 15 minutes, 0.73 ±0.49% for 1 hour, and 0.018±0.002% for 24 hours. For the IN.PACT DCB, the drug transfer percent was 1.58±1.49% for 15 minutes, 1.20±1.05% for 1 hour, and 1.58±1.41% for 24 hours. For the Stellarex DCB, the drug transfer percent was 0.79±0.43% for 15 minutes,1.60±0.92% for 1 hour, and 0.99±1.096% for 24 hours. Our results show a very small amount ( < 2%) of PTX is transferred from the DCB to the artery wall, regardless of which manufacturer. Further studies are warranted to quantify drug loss within the circulating media or non-target tissue and to perform parallel animal studies.

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