Phase 1 Safety and Tolerability Study of REGN9533 in Healthy Adults

NCT ID: NCT06665828

Last Updated: 2025-12-09

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE1
• Total Enrollment: 72 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-03-04
• Study Completion Date: 2026-01-29

Brief Summary

The aim of this clinical trial is to see how safe and tolerable the clinical trial drug (REGN9533) is in healthy participants. This is the first time that REGN9533 will be given to humans.

After the clinical trial drug has been tested in healthy participants, future studies with REGN9533 will focus on participants with thromboembolic (blocking of blood vessels) diseases which include blood clots.

REGN9533 is a drug that is only used in clinical studies.

The clinical trial is looking at:

• The side effects REGN9533 might cause
• How much REGN9533 is in the blood at different times
• How the body reacts to REGN9533
• If the body makes antibodies to REGN9533 (unwanted immune response, which may cause REGN9533 to not work as well)
• What is the best dose of REGN9533

Conditions

Healthy Volunteer

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

REGN9533

Randomized as described in the protocol Escalating Cohorts including Optional Cohorts

Group Type: EXPERIMENTAL

REGN9533

Intervention Type: DRUG

Administered per the protocol

Placebo

Randomized as described in the protocol

Group Type: EXPERIMENTAL

Matching Placebo

Intervention Type: DRUG

Administered per the protocol.

Interventions

REGN9533

Administered per the protocol

Intervention Type: DRUG

Matching Placebo

Administered per the protocol.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

1. Has a body mass index between 18 and 32 kg/m2, inclusive

2. Is judged by the investigator to be in good health based on medical history, physical examination, vital sign measurements, and electrocardiograms (ECGs) performed at screening and/or prior to administration of initial dose of study drug

3. Normal aPTT, normal PT, and normal platelet counts as described in the protocol

4. Hemoglobin values at screening period and at day -1 as described in the protocol

5. Negative Fecal Occult Blood Test (FOBT) during screening period

6. Normal Bleeding Time Test (BTT) at day -1 as defined by the study site

Exclusion Criteria

1. History of any major surgical procedure or clinically significant physical trauma within the last 6 months that in the opinion of the investigator may pose a risk to the participant by study participation

2. History of clinically significant bleeding, requiring hospitalization or blood products within the last 6 months, that in the opinion of the investigator may pose a risk to the participant by study participation

3. History of bleeding diathesis (eg, including, but not limited to Hemophilia A or B, von Willebrand's Factor deficiency, fibrinogen deficiency, and other inherited or acquired bleeding disorders)

4. History of clinically significant cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychiatric, or neurological disease, as assessed by the investigator, that may confound the results of the study or poses an additional risk to the participant by study participation

5. Is a current smoker including e-cigarettes or other nicotine-containing products; or is a former smoker including e-cigarettes or other nicotine-containing products which they have used at any time within 3 months prior to the screening visit

6. Has a confirmed positive drug test result at the screening visit and/or prior to randomization; or a history of recreational drug use (eg, marijuana) and/or drug or alcohol abuse within a year prior to the screening visit

7. Any malignancy, except for non-melanoma skin cancer or cervical/anus in-situ, that have been resected with no evidence of metastatic disease for 3 years prior to the screening visit

8. Has a history of significant multiple and/or severe allergies (eg, latex gloves), or has had an anaphylactic reaction to prescription or non-prescription drugs or food

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Regeneron Pharmaceuticals

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Clinical Trial Management

Role: STUDY_DIRECTOR

Regeneron Pharmaceuticals

Locations

SGS Belgium NV_Edegem

Edegem, Antwerp, Belgium

Countries

Belgium

Other Identifiers

2024-515285-14-00

Identifier Type: CTIS

Identifier Source: secondary_id

R9533-HV-2411

Identifier Type: -

Identifier Source: org_study_id