Medtronic’s IN.PACT Admiral drug-coated balloon, used for the treatment of peripheral artery disease in leg arteries above the knee, provided a consistently favourable treatment effect in patients with diabetes in a landmark study of the investigational medical device, which is under review by the US Food and Drug Administration (FDA) for approval.
This finding comes from a pre-specified subgroup analysis of patients with diabetes in the IN.PACT SFA trial that was presented at the Vascular InterVentional Advances 2014 (VIVA 14) meeting during a late-breaking clinical trials session by Peter Schneider, chief of vascular surgery at Kaiser Foundation Hospital in Honolulu.
“Peripheral artery disease in patients with diabetes tends to be more advanced and complex and, as a result, more challenging to treat than it is in patients without diabetes,” explains Schneider, a principal investigator of the IN.PACT SFA trial. “While that tendency held true in this study, diabetes did not negate the magnitude of the difference in treatment effect. The patency rates were statistically significantly higher, by more than 20%, for all patients in the drug-coated balloon arm and for its diabetic patient subset.”
The IN.PACT SFA trial enrolled 331 subjects at 57 sites across Europe and the USA. All study subjects were randomised to treatment with the drug-coated balloon (DCB) or percutaneous transluminal angioplasty (PTA). Key outcomes from all patients in the IN.PACT SFA trial were presented for the first time in April 2014 at the Charing Cross International Symposium in London and will soon be published in a peer-reviewed medical journal.
The clinically driven target lesion revascularisation (CD-TLR) rates at 12 months were 2.4% for the drug-coated balloon group and 20.6% for the percutaneous transluminal angioplasty group (p<0.001), a highly statistically significant difference. CD-TLR accounts for repeat procedures due to recurrent symptoms related to the treated lesion.
Per protocol, primary patency rates were assessed at 12 months of follow-up and showed a highly statistically significant difference: 82.2% for the drug-coated balloon group and 52.4% for the percutaneous transluminal angioplasty group (p<0.001). Primary patency at 360 days was also calculated by Kaplan-Meier survival estimates; at this specific time point, it was 89.8% for the drug-coated balloon group and 66.8% for the PTA group. Primary patency means a restoration of adequate blood flow through the treated segment of the diseased artery.
Study subjects were well matched at the time of enrolment. The vast majority (approximately 95%) of the patients had moderate or severe claudication, a condition characterized by leg pain while walking due to restricted blood flow through the superficial femoral artery or proximal popliteal artery. The remaining 5% suffered from rest pain because of more advanced arterial disease.
In addition to disease severity, other baseline characteristics – including diabetes (40.5% vs. 48.6%) and hypertension (91.4% vs. 88.3%), as well as mean lesion length (8.94cm vs. 8.81cm) and percent of total occlusions treated (25.8% vs. 19.5%) – were similar between the two groups, with no statistically significant differences. Clinical outcomes, however, significantly favoured the drug-coated balloon group.
The IN.PACT Admiral drug-coated balloon received the CE mark in 2009 and has been used in standard clinical practice in Europe since. It remains an investigational medical device in the United States, pending FDA approval.