SWING trial 12-month data: Novel sirolimus DCB shows “great promise” in “challenging” CLTI population

The Sundance (Surmodics) sirolimus drug-coated balloon (DCB) has an “excellent” safety profile in a “challenging, real-world, predominantly CLTI [chronic limb-threatening ischaemia] population,” and has a primary patency rate of 80% at 12 months in a per-protocol analysis population.

Ramon Varcoe (Prince of Wales Hospital, Sydney, Australia) presented these findings from the SWING first-in-human study at the VEITHsymposium 2022 (15–19 November, New York, USA).

Varcoe, who is co-lead investigator of the trial, added that the research team observed no major amputations, “very low” rates of major adverse events, and “impressive” luminal gain, which was sustained out to six-month angiogram. In addition, Varcoe reported that Rutherford category and functional outcome measures were improved. “The Sundance sirolimus-coated balloon is a novel device,” Varcoe informed VEITH attendees. He elaborated: “It has a microcrystalline surface, but also a very sophisticated proprietary excipient, which, rather than using nanoparticles or microreservoirs uses chemistry to deliver the drug into the blood vessel wall and have it retain that much more so than the other devices on the market.”

The presenter noted that SWING is a prospective, multicentre, single-arm feasibility study that looked at patients with stenotic or occluded lesions, and enrolled 35 patients over eight sites in Australia, New Zealand, and Europe.

The investigators performed both an intention-to-treat and a per-protocol analysis, Varcoe informed the audience. “The reason for that was because [the trial] was conducted during the COVID-19 pandemic, so we lost seven patients to the primary endpoint of angiography,” he noted, adding that there were three post-protocol deviations. Therefore, the research team focused on the 25 patients who had the per-protocol analysis.

The presenter stressed that the patients included represent a “realworld” population, including a high proportion of patients who are smokers and have diabetes, as well as a majority of patients with Rutherford category 4 or 5 disease. “They also had high proportions of moderate-to-severe calcification in excess of 18%, and around a third of these patients had total occlusions,” he added.

The first of the study’s two primary endpoints pertained to safety—freedom from major adverse limb event (MALE) and perioperative death at 30 days following the index procedure. The primary efficacy endpoint was the rate of late lumen loss at six months, as assessed by quantitative vascular angiography. Both primary endpoints were achieved, Varcoe revealed.

In the per-protocol population, there