Rivaroxaban for Blood Clots

(RIVA-SVT Trial)

Recruiting at 1 trial location

Overseen By Tzu-Fei Wang, MD,MPH

Age: 18+

Sex: Any

Trial Phase: Phase 2 & 3

Sponsor: Ottawa Hospital Research Institute

Must be taking: Anticoagulants

Must not be taking: Antiplatelets, CYP3A4 inhibitors

Disqualifiers: Atrial fibrillation, PE, DVT, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 90 days

50 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to test a plan for using rivaroxaban, a blood thinner, to treat blood clots in the superficial veins of the leg. Participants will take either a standard low dose or a full dose of the medication to assess enrollment and acceptance of study procedures over a year. The trial seeks adults who have had a confirmed blood clot in their leg veins within the last two weeks and require blood thinner treatment. As a Phase 2 trial, this research measures the treatment's effectiveness in an initial, smaller group, offering participants a chance to contribute to important medical advancements.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are on certain medications like strong inhibitors of CYP 3A4 and P-gp or if you require high-dose aspirin or other antiplatelet agents.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that rivaroxaban is generally well-tolerated by patients. Some studies have found that rivaroxaban can lower the risk of blood clots returning without significantly increasing the risk of serious bleeding. For example, continuing rivaroxaban treatment after the initial period effectively reduced the chance of blood clots returning. However, rivaroxaban carries a higher risk of bleeding compared to some other treatments.

Patients who took standard doses of rivaroxaban experienced fewer recurring blood clots without a major increase in bleeding problems. While rivaroxaban does have some risks, its safety is well-documented, especially since the FDA has approved it for other uses. This means that while side effects like bleeding can occur, these risks are understood and managed. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatment for blood clots?

Rivaroxaban is unique because it offers a simpler and potentially more effective treatment regimen for blood clots compared to traditional options like warfarin and heparin. Unlike these standard treatments that often require regular blood monitoring and dietary restrictions, rivaroxaban is an oral medication that doesn't need such frequent monitoring, making it more convenient for patients. Researchers are excited about rivaroxaban's dual dosing strategy, which starts with a higher dose for rapid action followed by a maintenance dose, aiming to reduce clot risk effectively over time. This could mean a significant improvement in both patient experience and treatment outcomes.

What evidence suggests that rivaroxaban might be an effective treatment for superficial vein thrombosis?

Research has shown that rivaroxaban effectively treats blood clots. Studies have found that it significantly reduces the risk of recurrent venous thromboembolism (VTE). It outperforms aspirin in preventing these clots from returning. In this trial, participants in Group A will receive rivaroxaban at varying doses over 90 days, while those in Group B will receive a lower dose of rivaroxaban followed by a placebo. Rivaroxaban matches the effectiveness of traditional treatments but causes less major bleeding, making it a promising option for individuals with venous blood clots. ^{1 3 6 7 8}

Who Is on the Research Team?

Tzu-Fei Wang, MD,MPH

Principal Investigator

Ottawa Hospital Research Institute

Are You a Good Fit for This Trial?

This trial is for adults with superficial vein thrombosis (SVT) in the leg. Participants must be willing to take a blood thinner called rivaroxaban and agree to potentially receive a placebo. Specific inclusion and exclusion criteria details are not provided.

Inclusion Criteria

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.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either full-dose or prophylactic-dose rivaroxaban for up to 90 days

90 days

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Rivaroxaban

Trial Overview The study compares full-dose rivaroxaban against low-dose followed by placebo, over a period of 90 days, to see if enough people will join and follow the larger study plan. It's an early-stage trial that won't confirm safety or effectiveness yet.

How Is the Trial Designed?

Group I: Group A (Intervention) Experimental Treatment 1 Intervention

Day 1-21: 15mg Rivaroxaban twice per day Day 22-90: 20mg Rivaroxaban once a day for 69 days

Group II: Group B (Comparator) Active Control 2 Interventions

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

Who Is Running the Clinical Trial?

Ottawa Hospital Research Institute

Lead Sponsor

Trials

585

Recruited

3,283,000+

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6055557/

Clinical outcomes of prolonged anticoagulation with ... Continued rivaroxaban treatment beyond an initial 3‐ or 6‐month treatment period significantly lowered the risk of recurrent VTE without a significant increase ...

2. nejm.org nejm.org/doi/full/10.1056/NEJMoa1700518

Rivaroxaban or Aspirin for Extended Treatment of Venous ... Therefore, we found that rivaroxaban was more effective than aspirin for the prevention of recurrent venous thromboembolism and was associated ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S2475037922014649

Rivaroxaban in acute venous thromboembolism Rivaroxaban was reported as effective as traditional therapies for the acute treatment of venous thromboembolism (VTE) with fewer major bleeding ...

4. jacc.org jacc.org/doi/10.1016/j.jacadv.2025.101714

A Comparison of Outcomes With Apixaban, Rivaroxaban ... Any bleeding, major bleeding, and mortality were higher with rivaroxaban. Thrombotic event rates were similar. Conclusions. For patients with AF ...

5. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2793434

Rivaroxaban and Risk of Venous Thromboembolism in ... The 3-year rate of VTE in patients receiving placebo was 1.66%, and low-dose rivaroxaban plus aspirin was associated with reduced risk for VTE.

6. acc.org acc.org/latest-in-cardiology/articles/2025/01/14/14/38/rivaroxaban-beyond-6-weeks

Rivaroxaban Beyond 6 Weeks: Enhancing Outcomes in ... The primary efficacy outcome occurred in 11% of patients in the rivaroxaban arm and in 19% in the placebo arm (relative risk 0.59; 95% ...

7. ashpublications.org ashpublications.org/blood/article/144/Supplement%201/697/531539/Effectiveness-and-Safety-of-Rivaroxaban-Versus

Effectiveness and Safety of Rivaroxaban Versus Warfarin in ... Background: Rivaroxaban has been shown to be noninferior compared with warfarin in reducing the risk of venous thromboembolism (VTE) recurrence.

8. sciencedirect.com sciencedirect.com/science/article/pii/S2213333X23002548

The clinical outcomes of different doses of rivaroxaban in ... Standard-dose rivaroxaban reduced the risk of VTE recurrence without increasing the risk of major bleeding in patients with IDDVT.