Chronic limb-threatening ischemia (CLTI) is the most severe form of peripheral artery disease, a condition in which narrowed or blocked arteries reduce blood flow to the legs. People with CLTI may have severe leg pain at rest, non-healing wounds, or gangrene, and face a high risk of leg amputation and death. Even after successful procedures to restore blood flow to the leg (called revascularization), many patients still experience serious complications. Inflammation in the blood vessels is believed to play an important role in these poor outcomes. Colchicine is an anti-inflammatory medication that has been used safely for decades to treat gout and other inflammatory conditions. Recent large clinical trials have shown that a low dose of colchicine (0.5 mg per day) can reduce heart attacks and strokes in patients with coronary artery disease. However, it has not been studied in patients with CLTI. The CIRCLE-Asia trial (Colchicine in Chronic Limb-Threatening Ischemia for Reduction of Complications and Limb Events in Asia) is a pilot study designed to evaluate whether colchicine can improve outcomes in patients with CLTI who have recently undergone a successful procedure to restore blood flow to their leg. Treatment begins within 7 days of the procedure. This is a randomized, double-blind, placebo-controlled, multicenter trial conducted at five hospitals in Taiwan. A total of 200 adult patients with CLTI who have undergone successful revascularization will be randomly assigned in a 1:1 ratio to receive either colchicine 0.5 mg once daily or a matching placebo pill, in addition to their usual medications, for 12 months. Neither the patients nor the study doctors will know which treatment each patient receives. The main outcome of interest is amputation-free survival, defined as the time until major amputation of the affected leg (above the ankle) or death from any cause, over 12 months of follow-up. The study will also assess other important outcomes including major limb complications, heart attacks, strokes, wound healing, changes in blood flow measurements, inflammatory blood markers, quality of life, and medication safety. This pilot trial will provide the first randomized evidence on the potential benefits and safety of colchicine in CLTI patients and will help inform the design of a larger definitive trial.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
200
Colchicine 0.5 mg oral tablet (Colchicine Tablets 0.5mg, Synmosa), taken once daily in addition to standard of care, for 12 months. Treatment is initiated within 7 days of successful lower-extremity revascularization. For patients experiencing intolerance such as diarrhea or gastrointestinal discomfort, the dose may be reduced to 0.25 mg daily (half tablet). If the medication is considered harmful, treatment is interrupted and resumed when safe.
Matching placebo tablet, identical in appearance to the colchicine 0.5 mg tablet (supplied by Synmosa Biopharma Corporation), taken orally once daily in addition to standard of care, for 12 months. Treatment is initiated within 7 days of successful lower-extremity revascularization. The same dose adjustment and discontinuation rules apply as for the active treatment arm.
Shin Kong Wu Ho-Su Memorial Hospital
Taipei, Taipei, Taiwan
RECRUITINGChi Mei Medical Center
Tainan, Taiwan
NOT_YET_RECRUITINGNational Taiwan University Hospital
Taipei, Taiwan
RECRUITINGTaipei Veterans General Hospital
Taipei, Taiwan
NOT_YET_RECRUITINGLinkou Chang Gung Memorial Hospital
Taoyuan, Taiwan
NOT_YET_RECRUITINGAmputation-free survival
Defined as the time to major (above the ankle) amputation of the study limb or death from any cause
Time frame: 12 months
Number of Participants with Major (Above the Ankle) Non-Traumatic Amputation of the Study Limb
Number of participants who underwent major (above the ankle) non-traumatic amputation of the study limb during the 12-month follow-up period.
Time frame: 12 months
Major adverse limb event (MALE, including non-traumatic above-ankle amputation and major lower limb artery reintervention) and its components
Time frame: 12 months
Major adverse cardiovascular event (MACE, including non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death) and its components
Time frame: 12 months
Wound healing rates at 3, 6, 9 and 12 months for Rutherford 5 patients (or time to wound healing)
Time frame: 12 months
Number of Participants with Acute Limb Ischemia
Number of participants experiencing acute limb ischemia of the study limb during the 12-month follow-up period, adjudicated by a blinded clinical events committee.
Time frame: 12 months
Number of Deaths from Any Cause
Number of participants who died from any cause during the 12-month follow-up period.
Time frame: 12 months
Number of Deaths from Cardiovascular Causes
Number of participants who died from cardiovascular causes during the 12-month follow-up period, adjudicated by a blinded clinical events committee.
Time frame: 12 months
Number of Deaths from Limb-Related Causes
Number of participants who died from limb-related causes (e.g., fatal limb sepsis, complications of major amputation) during the 12-month follow-up period.
Time frame: 12 months
Number of Participants with Adverse Gastrointestinal Events
Number of participants experiencing adverse gastrointestinal events (including nausea, vomiting, abdominal pain, and diarrhea) during the 12-month treatment period.
Time frame: 12 months
Number of Participants with Adverse Hematologic Events
Number of participants experiencing adverse hematologic events (including leukopenia, thrombocytopenia, and anemia) during the 12-month treatment period.
Time frame: 12 months
Number of Participants with Serious Infections
Number of participants experiencing serious infections (defined as infections requiring hospitalization or intravenous antibiotics) during the 12-month follow-up period.
Time frame: 12 months
Number of Participants with Diarrhea
Number of participants experiencing diarrhea as an adverse event during the 12-month treatment period. Diarrhea is defined as the passage of three or more loose or watery stools within a 24-hour period, and severity is graded by the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Grade 1 = increase of \<4 stools/day over baseline; Grade 2 = increase of 4-6 stools/day; Grade 3 = increase of ≥7 stools/day or hospitalization indicated; Grade 4 = life-threatening consequences; Grade 5 = death.
Time frame: 12 months
Number of Participants with Drug Discontinuation Due to Any Adverse Event
Number of participants who permanently discontinued the study drug due to any adverse event during the 12-month treatment period.
Time frame: 12 months
Change in Health-Related Quality of Life as Measured by the EQ-5D-5L Index Score
Change from baseline in EQ-5D-5L index score at 12 months. The EQ-5D-5L is a generic health status questionnaire. Index scores range from -0.6 to 1.0, where higher scores indicate better health-related quality of life.
Time frame: Baseline and 12 months
Change in Disease-Specific Quality of Life as Measured by the VASCUQOL-6 Score
Change from baseline in Vascular Quality of Life Questionnaire-6 (VASCUQOL-6) summary score at 12 months. VASCUQOL-6 scores range from 6 to 24, where higher scores indicate better vascular disease-specific quality of life.
Time frame: Baseline and 12 months
Change in Walking Ability as Measured by the Walking Impairment Questionnaire (WIQ) Score
Change from baseline in Walking Impairment Questionnaire (WIQ) composite score at 12 months. The WIQ assesses walking distance, walking speed, and stair climbing. Each domain is scored from 0 to 100, where higher scores indicate better walking ability.
Time frame: Baseline and 12 months
Change in Ankle-Brachial Index (ABI)
Change from baseline in ankle-brachial index (ABI) of the study limb at 12 months. ABI is calculated as the ratio of ankle systolic blood pressure to brachial systolic blood pressure (unitless ratio). Higher values indicate better lower-extremity arterial perfusion.
Time frame: Baseline and 12 months
Change in Toe-Brachial Index (TBI)
Change from baseline in toe-brachial index (TBI) of the study limb at 12 months. TBI is calculated as the ratio of toe systolic blood pressure to brachial systolic blood pressure (unitless ratio). Higher values indicate better distal perfusion.
Time frame: Baseline and 12 months
Change in Transcutaneous Oxygen Pressure (TcPO2)
Change from baseline in transcutaneous oxygen pressure (TcPO2) of the study limb at 12 months, measured in mmHg. Higher values indicate better tissue oxygenation.
Time frame: Baseline and 12 months
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