REGN7508 to prevent blood clots in adults with solid tumors

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Assess Efficacy and Safety of REGN7508, a Monoclonal Antibody Against FXI, for Primary Prophylaxis of Cancer-Associated Thrombosis for Participants With Solid Tumors Undergoing Cancer Treatment (ROXI-CAT-I)

Phase 3 Interventional Regeneron Pharmaceuticals · NCT07410117

This study will test whether the experimental drug REGN7508 can prevent cancer-associated blood clots in adults with solid tumors who are receiving or about to start anticancer treatment or recovering from surgery.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment860 (estimated)
Ages18 Years and up
SexAll
SponsorRegeneron Pharmaceuticals Industry-sponsored
Locations12 sites (Hialeah, Florida and 11 other locations)
Trial IDNCT07410117 on ClinicalTrials.gov

What this trial studies

This is a Phase 3, randomized, placebo-controlled study comparing REGN7508 to placebo for prevention of cancer-associated thrombosis in adults with locally advanced or metastatic solid tumors who are at increased clotting risk. Eligible participants have a Khorana score of 2 or greater or a tumor genetic variant linked to higher VTE risk and an ECOG performance status of 0–2. Participants receive REGN7508 or placebo while receiving anticancer therapy (or shortly before/after such therapy) and are monitored for new venous or arterial thromboembolic events, adverse events, drug levels in blood, and anti-drug antibodies. The trial is being conducted at multiple clinical research sites in the United States.

Who should consider this trial

Good fit: Adults with histologically confirmed locally advanced or metastatic solid tumors, a Khorana score ≥2 or an agreed high-risk tumor genetic variant, ECOG 0–2, and who are receiving, about to start, or recovering from anticancer treatment are the intended participants.

Not a fit: Patients with high baseline bleeding risk (including bleeding disorders or hemorrhagic tumor sites), primary brain tumors or brain metastases, prior documented VTE/ATE, or cancers limited to basal or squamous cell skin carcinoma are excluded and unlikely to benefit from this trial.

Why it matters

Potential benefit: If successful, REGN7508 could lower the risk of blood clots in high-risk cancer patients, potentially reducing complications and hospitalizations.

How similar studies have performed: Existing trials of anticoagulants such as LMWH and DOACs have shown benefit in reducing cancer-associated thrombosis, but REGN7508 is a novel investigational agent without established clinical evidence for CAT prevention.

Eligibility criteria

Show full inclusion / exclusion criteria
Key Inclusion Criteria:

1. Has a histologically confirmed diagnosis of malignant solid tumors which are locally advanced or metastatic as described in the protocol
2. Has a Khorana thromboembolic risk score ≥2 at the time of screening or harbors a somatic documented tumor genetic variant known to be associated with an increased risk of VTE as described in the protocol
3. Has an Eastern Cooperative Oncology Group (ECOG) Performance Status 0 to 2 at the time of screening and day 1 prior to the first dose of study intervention

Key Exclusion Criteria:

1. Has known bleeding conditions (eg, Hemophilia A or B, von Willebrand's disease), hemorrhagic tumor sites, or other conditions with a high risk for bleeding (eg, hepatic disease associated with coagulopathy)
2. Has a cancer diagnosis consisting solely of basal cell or squamous cell skin carcinoma
3. Has a primary brain tumor or brain metastases as described in the protocol
4. Has a history of objective evidence of VTE or ATE, including incidental VTE identified by diagnostic imaging requiring anticoagulation
5. Has any condition that, as judged by the investigator, may confound the results of the study or would place the participant at increased risk of harm if he/she participated in the study

Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply

Where this trial is running

Hialeah, Florida and 11 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cancer-Associated ThrombosisVenous ThromboembolismDeep Vein ThrombosisPulmonary EmbolismArterial ThromboembolismSolid tumorsClinically Relevant Non-Major bleedingInternational Society of Thrombosis and Hemostasis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.