REGN7508 vs ASA for Blood Clots After Knee Surgery

(ROXI-ASPEN Trial)

Recruiting at 1 trial location

Overseen By Clinical Trials Administrator

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: Regeneron Pharmaceuticals

Must not be taking: Enoxaparin

Disqualifiers: Bleeding history, Thromboembolic disease, others

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

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

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

Compensation: Varies

Number of Visits: Unknown

Duration: 6 weeks

2000 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new drug, REGN7508, to determine if it prevents blood clots more effectively than Acetylsalicylic Acid (ASA) after knee replacement surgery. It also examines possible side effects and assesses the body's reaction to the drug. Individuals scheduled for a single knee replacement and in good health may qualify for this trial. The study compares REGN7508 with a placebo and ASA to identify the most effective option. As a Phase 3 trial, it represents the final step before FDA approval, offering participants an opportunity to contribute to a potentially groundbreaking treatment.

Will I have to stop taking my current medications?

The trial information does not specify if you need to stop taking your current medications. It's best to discuss this with the study team or your doctor.

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

Research has shown that REGN7508 may help prevent blood clots in patients undergoing knee surgery. Earlier studies found that REGN7508 was generally well-tolerated, with most patients not experiencing serious side effects. Some individuals did report mild reactions like headaches or nausea. Importantly, a phase 3 trial tested REGN7508, providing some evidence of its safety, though researchers need to confirm this with larger groups.

Acetylsalicylic acid (ASA), or aspirin, is also widely used to prevent blood clots. It is generally safe when used as directed, though it can sometimes cause stomach upset or increase bleeding risk. In summary, both treatments have demonstrated good safety records in previous studies, but this trial will offer more information on any potential side effects. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

REGN7508 is unique because it introduces a new mechanism of action for preventing blood clots after knee surgery. Most current treatments, like ASA (Aspirin), work by thinning the blood to prevent clot formation. However, REGN7508 targets specific pathways involved in clot formation, potentially offering a more precise and effective approach to managing this risk. Researchers are excited about REGN7508 because it could offer a more tailored treatment option with fewer side effects compared to traditional blood thinners.

What evidence suggests that this trial's treatments could be effective for preventing blood clots after knee surgery?

Research has shown that REGN7508, which participants in this trial may receive, helps prevent blood clots, such as venous thromboembolism (VTE), after knee replacement surgery. Earlier studies found that REGN7508 effectively reduced these clots, confirming its preventive ability. The treatment targets a specific part of the blood clotting process called factor XI, which plays a crucial role in forming clots. These findings suggest that REGN7508 could be a promising option for preventing blood clots in patients recovering from knee surgery. Meanwhile, another group in this trial will receive ASA, a standard treatment for preventing blood clots, to compare its effectiveness against REGN7508. ^{1 2 4 5 6}

Who Is on the Research Team?

Clinical Trial Management

Principal Investigator

Regeneron Pharmaceuticals

Are You a Good Fit for This Trial?

Adults in good health who are scheduled for primary elective unilateral total knee replacement surgery can participate. They must have satisfactory lab safety test results as per the study protocol.

Inclusion Criteria

Key

My lab tests show I am in good health.

I am scheduled for a first-time knee replacement on one knee.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either REGN7508 or Acetylsalicylic Acid (ASA) for prophylaxis of symptomatic venous thromboembolism after total knee arthroplasty

6 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment, including side effects and antibody development against the study drug

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• REGN7508

Trial Overview

The trial is comparing an experimental drug, REGN7508, with Acetylsalicylic Acid (ASA) to prevent blood clots after knee surgery. It will also measure how much of the drugs stay in the blood over time and check for any immune response against REGN7508.

How Is the Trial Designed?

Group I: REGN7508 and Placebo Experimental Treatment 2 Interventions

Group II: Placebo and ASA Active Control 2 Interventions

Who Is Running the Clinical Trial?

Regeneron Pharmaceuticals

Lead Sponsor

Trials

690

Recruited

948,000+

Founded

1988

Headquarters

Tarrytown, USA

Known For

Precision medicine

Top Products

Dupixent, EYLEA, Libtayo, Praluent

Leonard Schleifer

Regeneron Pharmaceuticals

Chief Executive Officer since 1988

MD and PhD in Medicine

George Yancopoulos

Regeneron Pharmaceuticals

Chief Medical Officer since 1997

MD from Harvard Medical School

Citations

1.

investor.regeneron.com

investor.regeneron.com/news-releases/news-release-details/phase-2-trials-demonstrating-antithrombotic-effect-two-novel

Phase 2 Trials Demonstrating Antithrombotic Effect of Two ...

As published and presented, the results showed that both REGN7508Cat and REGN9933A2 demonstrated clear efficacy for VTE prevention following ...

2.

clinicaltrials.gov

clinicaltrials.gov/study/NCT07015905

Study Details | NCT07015905 | REGN7508 Versus ...

The aim of the study is to see how effective the study drug is at preventing venous thromboembolism (VTE) and other related diseases after total knee ...

3.

pubmed.ncbi.nlm.nih.gov

pubmed.ncbi.nlm.nih.gov/41218619/

Efficacy and safety of REGN9933 A2 and REGN7508 Cat ...

The primary endpoint in both studies was objectively confirmed venous thromboembolism (a composite of asymptomatic deep-vein thrombosis of the ...

4.

thelancet.com

thelancet.com/journals/lancet/article/PIIS0140-6736(25)02097-5/fulltext?rss=yes

Efficacy and safety of REGN9933 A2 and REGN7508 Cat ...

The primary endpoint was the incidence of adjudicated, confirmed venous thromboembolism through day 12 after first dose, which was administered ...

5.

hcplive.com

hcplive.com/view/regeneron-s-factor-xi-antibodies-prevent-thromboembolism-after-knee-replacement

Regeneron's Factor XI Antibodies Prevent ...

REGN7508 and REGN9933 demonstrated efficacy in preventing VTE in knee replacement surgery patients, with distinct mechanisms targeting factor XI ...

6.

clinicaltrials.gov

clinicaltrials.gov/study/NCT07213778

NCT07213778 | REGN7508 Versus Acetylsalicylic Acid ...

The aim of the study is to see how effective the study drug is at preventing Venous Thromboembolism (VTE) and other related diseases after total knee ...