A Trial to Learn How Well REGN9933 and REGN7508 Work for Preventing Blood Clots, and How Safe They Are, in Adults Who Have a Peripherally Inserted Central Catheter (PICC) (ROXI-CATH)

A Master Protocol for a Phase 2 Randomized, Double-Blind, Placebo-Controlled Study of REGN9933 and REGN7508, Monoclonal Antibodies Against Factor XI for Prevention of Venous Thromboembolism in Patients With a Peripherally Inserted Central Catheter (ROXI-CATH)

This study is researching 2 different experimental drugs called REGN9933 and REGN7508 (called "study drugs"). The study is focused on adults undergoing a placement of a catheter in the vein, also called a 'PICC line'.

The aim of the study is to see how effective the study drug is at preventing venous thromboembolism (VTE) and other related disease after catheter placement.

The study is looking at several other research questions, including:

• What side effects may happen from taking the study drug
• How much study drug is in the blood at different times
• Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects)

Study Overview

• Status: Completed
• Conditions: Venous Thromboembolism
• Intervention / Treatment: Drug: REGN9933; Drug: REGN7508; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 195
• Phase: Phase 2

Contacts and Locations

Study Locations

• Bulgaria
  • Sofia, Bulgaria, 1000
    • Sveta Sofia Hospital
• Canada
  • Ontario
    • Hamilton, Ontario, Canada, L8V 1C3
      • Juravinski Hospital
    • London, Ontario, Canada, N6A 4L6
      • London Health Sciences Centre
    • Oshawa, Ontario, Canada, L1G 2B9
      • Lakeridge Health
    • Toronto, Ontario, Canada, M5G 2M9
      • University Health Network
• Israel
  • Jerusalem, Israel, 91120
    • Hadassah University Medical Center
  • Netanya, Israel, 4244916
    • Lanadio Medical Center
  • Petah Tikva, Israel, 49100
    • Rabin Medical Center
  • Ramat Gan, Israel, 5265601
    • Sheba Medical Center
  • Tel Aviv, Israel, 64239
    • Tel Aviv Sourasky Medical Center
  • Jerusalem
    • Jerusalem, Jerusalem, Israel, 9103102
      • Shaare Zedek Medical Center
  • Southern District
    • Beersheba, Southern District, Israel, 84101
      • Soroka University Medical Center
• Romania
  • Bucharest, Romania, 011658
    • Arensia Research Clinic
  • Cluj-Napoca, Romania, 400006
    • Arensia Exploratory Medicine Clinic at Country Hospital Cluj-Napoca
• United Kingdom
  • Newcastle upon Tyne, United Kingdom, NE1 4LP
    • The Newcastle Upon Tyne Hospitals NHS Foundation Trust
  • Hampshire
    • Southampton, Hampshire, United Kingdom, SO16 6YD
      • University Hospital Southampton
  • Wales
    • Cardiff, Wales, United Kingdom, CF14 4XW
      • Cardiff and Vale University Health Board - University Hospital Wales
• United States
  • California
    • Los Angeles, California, United States, 90048
      • Cedars-Sinai Medical Center
  • Florida
    • Miami, Florida, United States, 33136
      • Sylvester Comprehensive Cancer Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02115
      • Brigham and Women's Hospital
  • Michigan
    • Detroit, Michigan, United States, 48202
      • Henry Ford Health System
  • New York
    • New York, New York, United States, 10029
      • Mount Sinai Medical Center
    • New York, New York, United States, 10065
      • Memorial Sloan Kettering

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

1. PICC is clinically indicated for at least 14 days and is anticipated to remain in place for at least 14 days
2. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤2 or equivalent functional status as described in the protocol
3. Body weight ≥45 kg and ≤130 kg during the screening period
4. International normalized ratio (INR) and aPTT values at or below the upper limit of normal as defined by the local lab during the screening period
5. Platelet count ≥100 x 10^9/L during the screening period as described in the protocol

Key Exclusion Criteria:

1. Unsuccessful PICC placement or any other complication associated with this procedure that in the opinion of the study investigator may present any safety concerns to the participant
2. History of prior venous thrombosis in the arm in which the PICC is to be placed
3. Peripheral catheter(s) in the same arm in which the PICC is to be placed or expected need for peripheral catheter(s) placement in the same arm the PICC is to be placed as described in the protocol
4. History of known thromboembolic disease or thrombophilia
5. Participants requiring therapeutic anticoagulation and/or antiplatelet therapy as described in the protocol
6. Expected to receive cancer therapy or other medication associated with a prior episode of Grade 4 thrombocytopenia as described in the protocol
7. Any history of intracranial or intraocular bleeding, excessive operative or post-operative bleeding, traumatic spinal or epidural anesthesia, or history of bleeding diathesis (such as but not limited to Hemophilia A or B, von Willebrand's disease, fibrinogen deficiency, and other inherited or acquired bleeding disorders) as described in the protocol

Note: Other protocol defined inclusion/exclusion criteria apply

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: REGN9933; Randomized 1:1:1	Drug: REGN9933; Intravenous (IV) single dose administered
Experimental: REGN7508; Randomized 1:1:1	Drug: REGN7508; IV single dose administered
Placebo Comparator: Placebo; Randomized 1:1:1	Drug: Placebo; IV single dose administered

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of confirmed VTE per central reading center (CRC) review	Through Day 14
Incidence of treatment-emergent adverse event (TEAEs)	Up to Day 100
Severity of TEAEs	Up to Day 100

Secondary Outcome Measures

Outcome Measure	Time Frame
Incidence of confirmed PICC associated venous thrombosis per CRC review	Through Day 14
Incidence of major bleeding	Through Day 14
Incidence of clinically relevant non-major (CRNM) bleeding	Through Day 14
Concentrations of REGN9933 in serum	Up to Day 75
Concentrations of REGN7508 in serum	Up to Day 75
Change in activated partial thromboplastin time (aPTT)	Up to Day 75
Change in prothrombin time (PT)	Up to Day 75
Incidence of anti-drug antibody (ADA) to REGN9933 over time	Up to Day 75
Incidence of ADA to REGN7508 over time	Up to Day 75
Magnitude of ADA to REGN9933 over time	Up to Day 75
Magnitude of ADA to REGN7508 over time	Up to Day 75

Collaborators and Investigators

• Sponsor: Regeneron Pharmaceuticals
• Investigators: Study Director: Clinical Trial Management, Regeneron Pharmaceuticals

Publications and helpful links

Helpful Links

• ROXI-CATH

Study record dates

Study Major Dates

• Study Start (Actual): September 20, 2024
• Primary Completion (Actual): March 27, 2026
• Study Completion (Actual): March 27, 2026

Study Registration Dates

• First Submitted: March 1, 2024
• First Submitted That Met QC Criteria: March 1, 2024
• First Posted (Actual): March 7, 2024

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Venous Thromboembolism; Anti-factor XI (FXI) monoclonal antibody; Peripherally inserted central catheter
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Thromboembolism; Venous Thromboembolism; Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: R9933-DVT-2308; 2023-508603-21-00 (Ctis: EU CT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.

IPD Sharing Time Frame

When Regeneron has:

• received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development
• made results publicly available (e.g., scientific publication, scientific conference, clinical trial registry)
• the legal authority to share the data, and
• ensured the ability to protect participant privacy

• IPD Sharing Access Criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No