Colchicine to Quench the Inflammatory Response After Deep Vein Thrombosis (The Conquer-DVT Pilot Trial)

Phase 3

Recruiting

• Conditions: Venous Thromboembolism
• Interventions: Drug: Placebo 0.5 mg po; Drug: Colchicine 0.5 mg po

• Registration Number: NCT06440694
• Lead Sponsor: Ottawa Hospital Research Institute

Brief Summary

This trial seeks to assess the feasibility of a full-scale, double-blind, placebo-controlled, randomized trial assessing whether low-dose colchicine (0.5 mg daily) reduces the risk of post-thrombotic syndrome (PTS) in patients with proximal lower extremity deep vein thrombosis (DVT).

Detailed Description

Eligible and consenting patients will be randomized via a central web-based randomization system (1:1 ratio) to receive one tablet of colchicine 0.5 mg or identical matching placebo daily starting within 7 days of initiation of anticoagulation for acute, symptomatic, proximal lower extremity Deep Vein Thrombosis (DVT) for a treatment course of 180 days (+/- 7 days). Study drug will start within 24 hours of randomization. The type, dose, and duration of anticoagulant therapy : unfractionated heparin, Low Molecular Weight Heparin (LMWH), fondaparinux, Direct Oral Anticoagulation (DOAC) or Vitamin K Agonist (VKA) will be left to the discretion of the treating physician or local investigator. The study drug will be continued until the end of the treatment period (180 days +/- 7 days). All patients will be observed until the end of study follow-up (365 days +/- 7 days).

Study Timeline

• Study First Submitted: 2024-05-28
• Study First Submitted QC: 2024-05-28
• Study First Posted: 2024-06-04
• Status Verified: 2025-07
• Study Start: 2025-07-07
• Last Update Submitted: 2025-07-09
• Last Update Posted: 2025-07-14
• Primary Completion: 2027-12-01
• Study Completion: 2027-12-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 150

Inclusion Criteria

• Consenting patients 18 years of age or older with a first, acute, symptomatic proximal (popliteal vein or more proximal) objectively confirmed DVT of the lower extremity will be eligible to participate in the study.

Exclusion Criteria

1. History of an allergic reaction or significant sensitivity to colchicine.
2. Requirement of colchicine for other indications.
3. Active or chronic diarrhea, or documented inflammatory bowel disease (i.e., Crohn's disease or ulcerative colitis), collagenous colitis or irritable bowel syndrome or existing blood dyscrasias.
4. Known or suspected, recent (<30 days) or active infections (acute or chronic).
5. History of cirrhosis, chronic active hepatitis, or severe liver disease.
6. Recent (<30 days) or chronic use of systemic (oral, intravenous) immunosuppressive drugs (including but not limited to steroids, tumor necrosis factor-alpha blockers, cyclosporine).
7. Known active cancer.
8. Any of the following as measured within the past 1-3 months or at screening: alanine, or aspartate aminotransferase >3 times the upper limit of normal, total bilirubin >2 times the upper limit of normal and a creatinine clearance by Cockcroft-Gault formula <30 mL/min.
9. Pregnancy, breast feeding or may be considering pregnancy during the study period or women of childbearing potential unwilling to use appropriate contraception during sex;
10. The use of medication with known drug-to-drug interactions (including but not limited to erythromycin or clarithromycin).
11. Unable or unwilling to provide consent.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Control Arm : Placebo	Placebo 0.5 mg po	Placebo 0.5 mg po once daily for 180 days. After the Day - 180 follow up, the study treatment will be discontinued and subsequent treatment will be at the discretion of the attending physician.
Experimental Arm: Colchicine	Colchicine 0.5 mg po	Colchicine 0.5 mg po once daily for 180 days. After the Day - 180 follow up, the study treatment will be discontinued and subsequent treatment will be at the discretion of the attending physician.

Primary Outcome Measures

Name	Time	Method
Pilot Trial Primary Outcome: Recruitment Rate	12 months	Mean number of participants recruited per site per month
Full-Scale Trial Primary Outcome: Post Thrombotic Syndrome	180 days	VILLALTA scale score ≥5 signifies clinically meaningful Post Thrombotic Syndrome

Secondary Outcome Measures

Name	Time	Method
Pilot Trial Secondary Outcome: Eligibility Rate	12 months	Proportion of screened patients who are eligible
Pilot Trial Secondary Outcome: Consent Rate	12 months	Proportion of eligible patients who provide consent
Pilot Trial Secondary Outcome: Retention Rate	12 months	Proportion of participants retained at follow-up
Pilot Trial Secondary Outcome: Study Completion Rate	12 months	Proportion of participants who completed all study procedures
Pilot Trial Secondary Outcome: Adherence Rate	12 months	Adherence to study drug measured by pill count at the end of follow-up
Pilot Trial Secondary Outcome: Reasons for declining participation	12 months	Pilot Trial Secondary Outcome: Reasons for declining participation
Full-Scale Trial Secondary Outcome: Post Thrombotic Syndrome	365 days	VILLALTA scale score ≥5 signifies clinically meaningful Post Thrombotic Syndrome
Full-Scale Trial Secondary Outcome: Severe Post Thrombotic Syndrome	180 and 365 days	VILLALTA scale score ≥ 15 signifies significant clinically meaningful Post Thrombotic Syndrome or presence of ulcer will be collected
Full-Scale Trial Secondary Outcome: Severity of Post Thrombotic Syndrome	180 and 365 days	Continuous VILLALTA score (VILLALTA scale score ≥5 signifies clinically meaningful Post Thrombotic Syndrome)
Full-Scale Trial Secondary Outcome: Patient Reported VILLALTA Scale	180 and 365 days	Full-Scale Trial Secondary Outcome: Patient Reported VILLALTA Scale (VILLALTA scale score ≥5 signifies clinically meaningful Post Thrombotic Syndrome)
Full-Scale Trial Secondary Outcome: Recurrent Venous Thromboembolism	180 and 365 days	Full-Scale Trial Secondary Outcome: Recurrent Venous Thromboembolism
Full-Scale Trial Secondary Outcome: Major Bleeding	180 and 365 days	As per International Society on Thrombosis and Haemostasis (ISTH) definition
Full-Scale Trial Secondary Outcome: Clinically Relevant Non-Major Bleeding	180 and 365 days	As per ISTH definition
Full-Scale Trial Secondary Outcome: Overall Mortality	180 and 365 days	Full-Scale Trial Secondary Outcome: Overall Mortality
Full-Scale Trial Secondary Outcome: Venous disease Specific Quality of Life	180 and 365 days	Scoring using VEINES-QOL/Sym (The VEINES-QOL summary score (based on 25 items) estimates the impact of chronic venous disease upon QOL)
Full-Scale Trial Secondary Outcome: Health-Related Quality of Life	180 and 365 days	Scoring using EuroQoL-EQ-5D-5L (EQ-5D-5L index scores range from -0.59 to 1, where 1 is the best possible health state)
Full-Scale Trial Secondary Outcome: Incremental Cost-Effectiveness Ratio (ICER)	180 and 365 days	Full-Scale Trial Secondary Outcome: Incremental Cost-Effectiveness Ratio (ICER)

Trial Locations

Locations (1)

The Ottawa Hospital General Campus; 🇨🇦 Ottawa, Ontario, Canada