Written by Katrina Mountford, Medical Editor.
19th March 2018
Dr Zeller began by summarising the advantages of the drug-coated balloon (DCB), which include preserving treatment options, excellent mid-term patency and target lesion revascularisation (TLR). However, limitations have emerged with the commonly used paclitaxel DCB, including its performance in calcified lesions, distal particulate embolisation and safety in sub-intimal percutaneous transluminal angioplasty (PTA). A sirolimus DCB offers potential advantages: its mode of action is cytostatic rather than cytotoxic; it has anti-inflammatory effects and a much wider safety margin and therapeutic window.
The Selution™ is a sirolimus-coated balloon that uses micro-reservoirs comprising a biodegradable polymer mixed with sirolimus. These micro-reservoirs are contained within a transfer membrane that utilises a proprietary cell adherent technology (CAT™). This protects the micro-reservoirs during balloon insertion, lesion crossing and inflation. The transfer membrane releases from the balloon surface and adheres to the vessel lumen during short balloon inflation. This minimises drug loss during transit to lesion and inflation. When compared with the Lutonix and In.Pact, the Selution™ DCB shows much higher drug transfer to the vessel within 1 hour (39 % vs 5 % and 1 % for the Lutonix and In.Pact, respectively). The Selution™ also achieves much higher arterial tissue drug concentration at all time points between 1 hour and 60 days, by which time no drug is detectable from the Lutonix and In.Pact, and lower drug dose per balloon size. The Selution™ has demonstrated excellent coating durability, with no flaking.
The clinical efficacy and safety of the Selution™ DCB in lesions of the superficial femoral artery was assessed in the prospective, controlled, multicentre, open-label single arm FIM clinical trial (NCT02941224), which involved 50 patients enrolled across four German centres. Median late lumen loss (LLL) of the target lesion, as measured by quantitative vascular angiography (QVA) at six months post-index procedure, was 0.19 mm. The rate of TLR was 2.2 %. There were no incidences of either death or the need for minor and/or major amputations. These are among the lowest LLL and TLR to be reported in a clinical study of DCBs. Assessment of the Selution™ DCB in long lesion was limited by low numbers: 26 % of participants at 6-month follow up had lesions of 8 to 15 mm, but demonstrated similar results to the overall cohort. These outcomes were excellent in a population that included calcified lesions in 34 % of participants.
In summary, this is the first demonstration of sirolimus safety and efficacy in peripheral intervention in humans. Further studies are required to confirm these findings in larger patient populations.