Major Adverse Limb Events in Patients With Femoro-popliteal and Below-the-knee Peripheral Arterial Disease Treated With Either Sirolimus-coated Balloon or Standard Uncoated Balloon Angioplasty

The SirPAD trial is an academic, investigator-initiated, single-center, randomized, non-inferiority, open-label clinical trial investigating whether the use of sirolimus-coated balloon catheters in patients with peripheral artery disease of the femoro-popliteal or below-the-knee segment is not inferior to that of uncoated balloon catheters for major clinical outcomes (unplanned major amputation, target limb re-vascularization) and may provide advantages concerning important secondary outcomes, which will be evaluated using a pre-specified hierarchical order as part of the primary analysis.

Study Overview

• Status: Active, not recruiting
• Conditions: Peripheral Arterial Disease
• Intervention / Treatment: Device: sirolimus-coated balloon catheter; Device: uncoated balloon catheter

Detailed Description

Peripheral artery disease (PAD) is a progressive atherosclerotic disease with symptoms ranging from intermittent claudication (IC) to critical limb ischemia (CLI). The majority of symptomatic PAD patients present with atherosclerotic lesions located in the femoro-popliteal arteries and endovascular therapy is the primary choice if the stenosis/occlusions involve <25 cm of the vessel. A minority of symptomatic PAD patients would present with infra-popliteal (distal or below-the-knee) lesions: in these patients, the endovascular treatment is challenging.

Drug-coated balloons (DCB) and drug-eluting stents (DES) were developed to prevent neo-intimal proliferation and restenosis after percutaneous transluminal angioplasty (PTA), an objective which had been achieved by the local application of either cytostatic (e.g. paclitaxel - a cytoskeletal disruptor) or immunosuppressive (e.g. sirolimus/everolimus - both mTOR inhibitors) substances on the vessel wall.

Over the past decade, a few randomized controlled trials (RCT) compared the efficacy and safety of drug-coated (mainly paclitaxel-coated) devices vs. that of uncoated ones, and demonstrated a significant reduction in restenosis rates, late lumen loss, and incidence of target lesion re-vascularization. However, the size of these trials was often too small to draw firm conclusions concerning major clinical outcomes. Moreover, substantial heterogeneity of the study populations and too restrictive eligibility criteria limited their external validity, leading to a difficult interpretation of the results of later meta-analyses. Indeed, these trials adopted as the primary outcome surrogate (and rather subjective) outcomes, such as vessel patency and target limb re-vascularization, which may be difficult to objectively adjudicate in the setting of an open-label trial, rather than ´hard´ objective clinical endpoints, such as major amputation or urgent revascularization due to critical limb ischemia.

Moreover, despite the short-term effects appeared promising based on imaging outcome, tthe results of a recent meta-analysis of 28 trials showed an increased two-year mortality in the group of patients treated with paclitaxel-coated balloons. Based on these results, and after analysis of follow-up data from the trials that led to the approval of these products, a Food and Drug Administration (FDA) panel concluded that, despite the short-term benefits with paclitaxel-based devices, safety concerns may exist for mid-term mortality risk.

Alternative drug candidates to paclitaxel-coated balloon catheters are the so-called limus-based analogs, which own cytostatic properties and are characterized by a wider therapeutic window. Recently, a novel balloon catheter has been CE-certified: it encapsulates sirolimus in phospholipid drug nanocarriers to improve adhesion properties of sirolimus and to provide better bioavailability. Similarly to paclitaxel-coated and uncoated devices, sirolimus-coated devices are currently approved for routine use in PAD and reimbursed in Switzerland.

The aim of the present trial is to compare the efficacy, as defined by a composite of clinically relevant non-subjective ´hard´ outcomes (major amputation and target lesion re-vascularization for critical limb ischemia), of sirolimus-coated vs. uncoated balloon angioplasty for peripheral artery disease in patients scheduled for infra-inguinal re-vascularization and selected based on a very limited number of inclusion criteria (all comers) aiming at maximization of external validity.

• Study Type: Interventional
• Enrollment (Estimated): 1200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Fribourg, Switzerland, 1708
    • HFR Fribourg - Hôpital Cantonal / Kantonsspital
  • Canton of Zurich
    • Zurich, Canton of Zurich, Switzerland, 8091
      • University Hospital Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥18 years
• Patients requiring endovascular angioplasty for PAD located below the inguinal ligament
• Written informed consent obtained from participant or legal guardian prior to randomization; in patients requiring emergency interventional treatment who are temporarily not capable of providing informed consent, consent will be subsequently obtained after the procedure if strict conditions apply. These include the assessment of the presumed will and patient decree, and requires the allocation of an independent physician

Exclusion Criteria:

• Pregnancy, breastfeeding, or planned pregnancy within the trial period or women of childbearing potential not using an adequate method of contraception
• Patients with known intolerance or allergy to sirolimus
• Participation in this or other clinical trials during the previous 3 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sirolimus-coated group	Device: sirolimus-coated balloon catheter; angioplasty with sirolimus-coated balloon catheter
Active Comparator: Uncoated group	Device: uncoated balloon catheter; angioplasty with uncoated balloon catheter

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary efficacy outcome is a composite of two major adverse limb events (MALE): unplanned major amputation of the target limb or endovascular/surgical target lesion re-vascularization for critical limb ischemia occurring within one year.	An unplanned major amputation is defined as any amputation above the ankle on the target limb, which was not planned or not expectable at the time of screening or randomization. Patients with scheduled amputation undergoing re-vascularization to improve wound healing are referred to as planned amputation and will not count for the primary outcome.; Critical limb ischemia is defined according to a Fontaine stage (classes III-IV) or according to criteria for a critical haemodynamic status, as defined in the ESC guidelines.	One year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite of unplanned (major or minor) index-limb amputations or any target lesion re-vascularization within one year of enrollment	Unplanned major amputation is defined analogously to the definition used for the primary efficacy endpoint. Unplanned minor amputation is defined as amputation below or at the level of the ankle, which was not planned or not expected at the time of randomization.	One year

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Death from all causes	Death from all causes within 30 days, 180 days, one year, two years, and five years	up to five years
Serious adverse events (SAEs)	Serious adverse events (SAEs) during initial hospitalization, within 180 days, and within 365 days	one year
Serious adverse device related events (SADE)	Serious adverse device related events (SADE) during initial hospitalization	up to one month
A composite of all-cause death and MALE	A composite of all-cause death and MALE within 30 days	one month

Collaborators and Investigators

• Sponsor: Nils Kucher
• Investigators: Principal Investigator: Nils Kucher, Prof., University of Zurich

Publications and helpful links

General Publications

• Barco S, Sebastian T, Voci D, Engelberger RP, Grigorean A, Holy E, Leeger C, Munger M, Periard D, Probst E, Spescha R, Held U, Kucher N. Major adverse limb events in patients with femoro-popliteal and below-the-knee peripheral arterial disease treated with either sirolimus-coated balloon or standard uncoated balloon angioplasty: a structured protocol summary of the "SirPAD" randomized controlled trial. Trials. 2022 Apr 21;23(1):334. doi: 10.1186/s13063-022-06242-8.

Study record dates

Study Major Dates

• Study Start (Actual): November 3, 2020
• Primary Completion (Actual): December 31, 2025
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: January 15, 2020
• First Submitted That Met QC Criteria: January 22, 2020
• First Posted (Actual): January 23, 2020

Study Record Updates

• Last Update Posted (Actual): February 19, 2026
• Last Update Submitted That Met QC Criteria: February 17, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Peripheral Vascular Diseases; Peripheral Arterial Disease; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antineoplastic; Antineoplastic Agents; Antifungal Agents; Immunosuppressive Agents; Immunologic Factors; Physiological Effects of Drugs; Sirolimus
• Other Study ID Numbers: SirPAD Trial

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No