Advice

Summary

Summary

The ClearWay RX is a rapid exchange perfusion catheter for localised delivery of diagnostic or therapeutic agents, including drugs such as abciximab to dissolve blood clots in coronary arteries. The relevant evidence for this indication is very limited in quantity and comes from 2 small randomised controlled trials (1 available only as a conference presentation) which were inadequately or not powered to detect important differences in clinical outcomes. The published COCTAIL trial showed no significant difference in the primary outcome (thrombus score) but improvement in some outcomes for patients having abciximab using ClearWay RX compared with guide catheter or intravenous administration. These included the extent of stenosis, thrombolysis in myocardial infarction frame count, procedure-related myocardial infarctions and major adverse coronary events at 1 year. The list price of a single ClearWay RX unit is £600 excluding VAT.

Note that administering drugs such as abciximab using ClearWay RX may be outside their UK marketing authorisation.

Product summary and likely place in therapy

  • The ClearWay RX is a rapid exchange perfusion balloon catheter, made from expanded polytetrafluoroethylene, for localised delivery of diagnostic or therapeutic agents including drugs.

  • This briefing evaluates its use for delivering abciximab to dissolve blood clots in coronary arteries, following episodes of unstable angina or myocardial infarction. It would replace standard delivery routes for the same drug, including intravenous or intracoronary administration, in patients for whom it is suitable.

Effectiveness and safety

  • The relevant evidence summarised in this briefing is very limited in quantity and comes from 2 randomised controlled trials including a total of 98 patients. Both trials evaluated patients with unstable angina or myocardial infarction and compared abciximab delivered into the coronary artery using the ClearWay RX catheter with guide catheter (COCTAIL), or intravenous delivery (Crystal AMI).

  • In the COCTAIL trial (n=50), there was no statistically significant difference in the primary outcome (thrombus score) with ClearWay RX compared with guide catheter delivery of abciximab. There was a statistically significant improvement in the extent of stenosis of the target artery, coronary blood flow as measured by the thrombolysis in myocardial infarction frame count (TIMI), procedure-related myocardial infarctions and major adverse cardiac events at 1 year with ClearWay RX. There was no significant difference between the 2 groups in myocardial blush grade (a measure of myocardial reperfusion) or in the number of target vessel revascularisations. However, the study was not powered adequately to detect important differences in clinical outcomes, included patients with a range of acute coronary syndromes, and did not assess long-term clinical outcomes. It was not designed to distinguish between the thrombolytic action of abciximab and the physical displacement of the thrombus using ClearWay RX.

  • The Crystal AMI trial (n=48) is reported as a conference presentation only and has not been peer-reviewed. The trial showed improvements in some outcomes for patients having ClearWay RX compared with patients having guide catheter but the report is lacking in detail and the trial is described as a proof-of-concept study which was not powered to detect statistically significant differences in clinical outcomes.

Technical and patient factors

  • The ClearWay RX's semi-compliant balloon design and atraumatic tip support its use in target vessels while reducing the potential for additional vessel trauma.

  • The ClearWay RX catheter is narrow (0.014" guidewire compatible), allowing it to be used during routine angioplasty. It allows for much higher local drug concentration than intravenous administration.

  • It is intended for use by interventional cardiologists trained in percutaneous interventional techniques, in settings such as cardiac catheterisation units.

  • There is currently a US Food and Drug Administration (FDA) consent decree applying to the ClearWay RX balloon catheter.

  • Administering drugs such as abciximab using ClearWay RX may be outside their UK marketing authorisation.

Cost and resource use

  • The list price of 1 ClearWay RX unit is £600 excluding VAT.

  • No published evidence on resource consequences was identified.