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Phase 1 Safety and Tolerability Study of REGN9533 in Healthy Adults

A Phase 1, Randomized, Double-Blind, Placebo Controlled Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single Ascending Doses of REGN9533, a Monoclonal Antibody Against Factor XII, in Healthy Adults

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06665828
Enrollment
72
Registered
2024-10-30
Start date
2025-03-04
Completion date
2026-01-29
Last updated
2026-02-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volunteer

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

Interventions

Administered per the protocol

DRUGMatching Placebo

Administered per the protocol.

Sponsors

Regeneron Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

Key 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 Key

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 Note: Other protocol-defined Inclusion/

Design outcomes

Primary

MeasureTime frame
Incidence of Treatment Emergent Adverse Events (TEAEs)Up to 100 days
Severity of TEAEsUp to 100 days

Secondary

MeasureTime frame
Change in activated Partial Thromboplastin Time (aPTT)Baseline up to 100 days
Change in Prothrombin Time (PT)Baseline up to 100 days
Concentrations of REGN9533Up to 100 days
Incidence of Anti-drug Antibodies (ADAs) to REGN9533Up to 100 days
Titer of ADAs to REGN9533Up to 100 days

Countries

Belgium

Contacts

STUDY_DIRECTORClinical Trial Management

Regeneron Pharmaceuticals

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 7, 2026