A Pilot Trial Comparing Full Dose Rivaroxaban to Prophylactic Dose Rivaroxaban in Patients With Superficial Vein Thrombosis in the Leg (RIVA-SVT)

August 5, 2025 updated by: Ottawa Hospital Research Institute

A Pilot Randomized Double-Blinded Comparison of Full Treatment Dose Rivaroxaban for 90 Days to Prophylactic Dose Rivaroxaban for 45 Days in Patients With Lower Extremity Superficial Vein Thrombosis

The goal of this clinical trial, called a pilot study or a feasibility study, is to test the study plan and to find out whether enough participants will join a larger study and accept the study procedures. This type of study includes a small number of participants so it is not expected to prove how safe the treatment is or how well the treatment works.

The main question it hopes to answer is:

1.What is the average number of patients that are recruited per month during the 12 month study period?

To test the study plan, adults being treated for a superficial vein thrombosis (SVT), which is a blood clot in the superficial veins of the leg, will be given a type of blood thinner called rivaroxaban. Half of the participants in this study will be given the standard (low-dose) rivaroxaban for 45 days, then 45 days of placebo (a substance that looks like the study medication but does not have any active or medicinal ingredients). The other half of participants will be given full-dose rivaroxaban for a total of 90 days. The placebo in this study is not intended to have any effect on the participants blood clot. A placebo is used to make the results of the study more reliable.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The standard or usual treatment for a superficial vein thrombosis (SVT) is to treat with a low-dose (often called a prophylactic dose) of blood thinner for 45 days. Rivaroxaban is a type of oral blood thinner that is used in the treatment and prevention of blood clots. Currently, rivaroxaban 10mg daily for 45 days is the most commonly used treatment in patients with lower extremity SVT.

Recent studies of participants with SVT suggest that treatment with full-dose (sometimes called therapeutic dose) blood thinners could be promising in preventing additional complications from SVT such as:

  • A new blood clot in the deep veins of the legs or arms
  • A new pulmonary embolism (a blood clot in the lungs)
  • A recurrence or extension of the existing SVT (the existing clot comes back after treatment is stopped or gets bigger)

The Investigators are studying whether a full-dose of rivaroxaban for 90 days could prevent or improve additional complications from SVT.

Study Type

Interventional

Enrollment (Estimated)

50

Phase

  • Phase 2
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Tzu-Fei Wang, MD,MPH
  • Phone Number: 73755 613-737-9988
  • Email: tzwang@toh.ca

Study Contact Backup

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, K1H 8L6
        • Recruiting
        • The Ottawa Hospital
        • Contact:
          • Veronica Bates, BSc, CCRP
          • Phone Number: 71068 613-737-8899
          • Email: vebates@ohri.ca
        • Principal Investigator:
          • Tzu-Fei Wang, MD, MPH
      • Ottawa, Ontario, Canada, K1K 0T2
        • Not yet recruiting
        • Hôpital Montfort
        • Contact:
        • Principal Investigator:
          • Miriam Kimptom, MD,MSc,FRCPC

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adult patients age ≥ 18 years old.
  2. Objectively confirmed diagnosis within 14 days of an acute symptomatic SVT of the lower extremities by standardized CUS, where SVT is defined as incompressibility of a venous segment located along the course of a known superficial vein.
  3. Anticoagulation for SVT is warranted per clinicians.
  4. Able and willing to provide written informed consent.

Exclusion Criteria:

  1. Other indication(s) for therapeutic or prophylactic dose anticoagulation (e.g. atrial fibrillation, mechanical valve, etc.).
  2. History of PE or DVT within 6 months (180 days) of screening.
  3. >5 days of any anticoagulants for the index SVT.
  4. Requires use of aspirin >100mg daily or other antiplatelet agents.
  5. Patients receiving concomitant systemic treatment with strong inhibitors of both CYP 3A4 and P-gp (e.g. cobicistat, ketoconazole, itraconazole, posaconazole, ritanovir, etc.).
  6. Active bleeding or history of CRNMB or major bleeding (as defined by the ISTH) within 30 days of screening.
  7. History of severe head trauma or ophthalmic, spinal, cerebral surgery within 90 days of screening.
  8. Have acute endocarditis.
  9. Thrombocytopenia (platelet count <50,000/uL), acute hepatitis, chronic active hepatitis, cirrhosis with severe hepatic impairment defined by a Childs-Pugh class B or C.
  10. Creatinine clearance <30 ml/min.
  11. Known contraindication to treatment with rivaroxaban.
  12. Are participating in another interventional trial that would compromise the results or integrity of this trial as determined by the investigator.
  13. Pregnant or breast feeding.
  14. Known hereditary or acquired severe hemorrhagic disease.
  15. Life expectancy <3 months.
  16. Unstable medical or psychological condition that would interfere with trial participation at the discretion of the site investigator.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group A (Intervention)
Day 1-21: 15mg Rivaroxaban twice per day Day 22-90: 20mg Rivaroxaban once a day for 69 days
Drug: Full dose rivaroxaban
The intervention group will receive full dose rivaroxaban for 90 days.
Active Comparator: Group B (Comparator)
Day 1-21: 10mg Rivaroxaban once a day AND placebo once a day Day 22-45: 10mg Rivaroxaban once a day Day 46-90: Placebo once a day for 45 days
Drug: Low dose rivaroxaban
The comparator group will receive the standard treatment of low dose rivaroxaban.
Drug: Placebo
Since the treatment arm has an AM and PM dose of study drug from Day 1-21, the comparator group will take 1 placebo pill in the PM to keep the two arms blinded.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Primary Feasibility Outcome
Time Frame: 12 months from when recruitment opens.
The primary feasibility outcome of this pilot trial is the average number of patients recruited per month during the 12 month recruitment period.
12 months from when recruitment opens.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Secondary Feasibility Outcomes
Time Frame: From the start of study recruitment to the last follow-up of the last participant enrolled.
The rate (%) of eligible patients that give consent to participate.
From the start of study recruitment to the last follow-up of the last participant enrolled.
Secondary Feasibility Outcomes
Time Frame: From the start of study recruitment to the last follow-up of the last participant enrolled.
The rate (%) of patients that are not lost to follow-up.
From the start of study recruitment to the last follow-up of the last participant enrolled.
Secondary Feasibility Outcomes
Time Frame: From the start of study recruitment to the last follow-up of the last participant enrolled.
The rate (%) of patients who complete and adhere to the study procedures.
From the start of study recruitment to the last follow-up of the last participant enrolled.
Secondary Feasibility Outcomes
Time Frame: From the start of study recruitment to the last follow-up of the last participant enrolled.
Reasons why eligible patients chose not to participate.
From the start of study recruitment to the last follow-up of the last participant enrolled.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ottawa Hospital Research Institute

Investigators

  • Principal Investigator: Tzu-Fei Wang, MD,MPH, Ottawa Hospital Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 6, 2025

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

April 22, 2025

First Submitted That Met QC Criteria

May 2, 2025

First Posted (Actual)

May 11, 2025

Study Record Updates

Last Update Posted (Actual)

August 11, 2025

Last Update Submitted That Met QC Criteria

August 5, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RIVA-SVT Pilot

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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