12-Month Results From the SWING Multicentre Study: A Novel Sirolimus-Coated Balloon for Use Below-the-Knee

Dr. Ramon Varcoe, from Prince of Wales Hospital in Sydney, Australia, presented results from SWING, a prospective, multicenter, single-arm, feasibility study that evaluated the safety and performance of a sirolimus-coated balloon.

Sirolimus is a potent anti-inflammatory, cytostatic drug with anti-proliferative effects, and proven safety and efficacy. To administer this drug, there must be a high initial transfer to form an adequate drug depot where the bioavailable drug can be released continuously into the arterial tissue at therapeutic levels over an extended period of time. It must be present for 90 days to inhibit a restenotic response.

SWING was a prospective, multicenter, single-arm, feasibility study that evaluated the safety and performance of the Sundance™ drug-coated balloon (DCB) in 35 patients at 8 test sites in Australia, New Zealand, and Europe.

The Sundance DCB has a uniform sirolimus drug coating, a hydrophilic shaft coating, and uses a Surmodics .014” percutaneous transluminal angioplasty platform. Its microcrystalline technology provides enhanced stability, uniform coating and drug dose density, and greater transfer and sustained levels in arterial tissue. In a comparison with competitor studies, the Sundance DCB showed a sirolimus concentration in porcine arterial tissue well above the levels attained by the Selution SLR and MagicTouch PTCA.

The SWING study population included subjects with stenotic or occluded lesions of the infrapopliteal arteries with a reference vessel diameter of 2 mm to 4 mm and a total lesion length <230 mm. Subjects had to have a Rutherford class 4 or 5 (class 3 was included but capped at 20% of the cohort), de novo or restenotic lesions, ≥70% stenosis, and up to 2 lesions in the same or different below-the-knee arteries. Good or successfully treated inflow and an unimpaired outflow artery in continuity to the ankle/foot was also required. There was a modified intent-to-treat (MITT) population and a per-protocol analysis population (PP) where the PP population was a subset of the MITT population.

The primary safety endpoint was freedom from major adverse limb event and perioperative death at 30 days. The primary efficacy endpoint was late lumen loss at 6 months assessed by quantitative vascular angiography.

SWING clinical results demonstrated an excellent safety profile with 12-month primary patency of 80% per protocol. The Sundance DCB should be evaluated in a large-scale pivotal trial to confirm these results.