Clinical trial NCT06444178: Assessment of Gastrointestinal Blood Loss After Receiving Aspirin or Aspirin Plus Rivaroxaban, or Aspirin Plus REGN9933, or Aspirin Plus REGN7508 in Healthy Adult Participants
Official title: A Parallel Group Study in Healthy Participants to Quantitate Increases in Subclinical Gastrointestinal Blood Loss Following Administration of Aspirin Alone or in Combination With Rivaroxaban or Factor XI Inhibitors (REGN9933 or REGN7508)
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE1
Conditions: Healthy Volunteers
Keywords: Gastrointestinal (GI) bleeding
Fecal occult blood testing (FOBT)
Lead sponsor: Regeneron Pharmaceuticals
Sponsor class: INDUSTRY
First posted: 2024-06-05
Enrollment: 224
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This study is researching experimental drugs called REGN9933 and REGN7508 (called "study drugs") and comparing their effects to approved treatments of rivaroxaban and aspirin (called "standard treatments"). Aspirin will be given alone or in combination with the study drugs or the other standard treatments to look at their effects on blood loss in the intestines.

The aim of the study is to see if aspirin alone or the study drugs REGN9933 and REGN7508, when taken with aspirin, cause less minor intestinal bleeding than standard treatments rivaroxaban with aspirin.

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 drug less effective or could lead to side effects)


Eligibility criteria: Key Inclusion Criteria:

1. Body mass index between 18.0 and 32.5 kg/m2 (inclusive) at the screening visit
2. 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 treatment
3. Normal aPTT, normal PT, and normal platelet counts at screening period and at the day 1 visit as defined by the local laboratory
4. Hemoglobin values within the normal range, per local laboratory, at the screening and day 1 visits
5. Negative FOBT at Baseline (visit 2) and visit 3 as defined in the protocol

Key Exclusion Criteria:

1. History of any major surgical procedure or clinically significant physical trauma in the last 6 months, in the opinion of the investigator, that may pose a risk to the participant by study participation
2. Whole blood donation within the previous 56 days or plasma donation within the previous 7 days prior to the screening visit
3. Hospitalized for any reason within 30 days of the screening visit
4. Estimated glomerular filtrate rate (eGFR) of \<60 mL/min/1.73m2 at screening as described in the protocol.
5. Current smoker or former smoker, including e-cigarettes, who stopped smoking within 12 months prior to the screening visit
6. History of illicit drug or alcohol abuse within the last 2 years prior to the day 1 visit
7. Use of any prescription and nonprescription medications or nutritional supplements from approximately 2 weeks or 5 half-lives, as described in protocol
8. Has elective surgery planned to occur prior to end of study (EOS)

Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply

Primary outcomes:
measure: Change in fecal hemoglobin content (FHC)
timeFrame: Baseline and up to day 22
Secondary outcomes:
measure: Incidence of treatment-emergent adverse events (TEAE)
timeFrame: Up to day 100
measure: Severity of TEAE
timeFrame: Up to day 100
measure: Incidence of major bleeding
timeFrame: Up to day 100
measure: Incidence of clinically relevant non-major (CRNM) bleeding
timeFrame: Up to day 100
measure: Concentrations of REGN9933
timeFrame: Up to day 29
measure: Concentrations of REGN7508
timeFrame: Up to day 29
measure: Change in activated partial thromboplastin time (aPTT)
timeFrame: Baseline and up day 29
measure: Change in prothrombin time (PT)
timeFrame: Baseline and up day 29
measure: Incidence of Anti-drug antibody (ADA) to REGN9933
timeFrame: Up to day 29
measure: Titer of ADA to REGN9933
timeFrame: Up to day 29
measure: Incidence of ADA to REGN7508
timeFrame: Up to day 29
measure: Titer of ADA to REGN7508
timeFrame: Up to day 29
Other outcomes:
Locations:
city: Leeds
country: United Kingdom
facility: Fortrea Clinical Development
Study officials:
affiliation: Regeneron Pharmaceuticals
name: Clinical Trial Management
role: STUDY_DIRECTOR
References: