Assess Gastrointestinal Blood Loss After Receiving Aspirin or Aspirin Plus Rivaroxaban in Healthy Adult Participants

Study Overview
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Brief Summary
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The primary objective of the study is to determine whether aspirin alone or aspirin combined with various doses of rivaroxaban causes subclinical GI blood loss as determined by the HemoQuant assay. The secondary objective of the study is to evaluate the safety and tolerability of aspirin alone or in combination with rivaroxaban to healthy volunteers.

Official Title
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A Parallel Group Study in Healthy Participants to Quantify Subclinical Gastrointestinal Blood Loss Following Administration of Aspirin Alone or Aspirin in Combination With Rivaroxaban

Conditions
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Healthy Volunteer

Intervention / Treatment
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* Drug: Aspirin
* Drug: rivaroxaban low dose
* Drug: rivaroxaban high dose


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Has a body mass index between 18 and 32 kilograms per metered square (kg/m2), inclusive Is judged by the investigator to be in good health based on medical history, physical examination, vital sign measurements, and electrocardiograms (ECGs) performed during screening Is in good health based on laboratory safety testing obtained at the screening visit Willing and able to abstain from alcohol use for the duration of the study Key Exclusion Criteria: History of anemia, abnormal bleeding (including vaginal bleeding or excessive menstrual periods), previous diagnosis of bleeding diathesis, or blood clots as defined in the protocol History, in the last year, of any bleeding GI lesions such as peptic ulcer, hemorrhoids or anal fissure, or a positive fecal occult blood test performed either during screening or on Day 1 Presence of irregular stool patterns, constipation, or frequent diarrhea that, in the opinion of the investigator, may interfere with stool collections required by the protocol Inability to refrain during study period from activities with high risk of bleeding or trauma such as planned surgery, contact sports, etc. Hemoglobin levels below the lower limit of normal as defined by local laboratory at screening; the lab may be repeated once if initially abnormal PT and aPTT values above the upper limit of normal as defined by the local laboratory during screening; the lab may be repeated once if initially abnormal Platelet count below the lower limit of normal as defined by the local laboratory during screening; the lab may be repeated once if initially abnormal History of clinically significant respiratory, hepatic, renal, GI, 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. History of any atherosclerotic cardiovascular disease Presents any concern to the study investigator that might confound the results of the study or poses an additional risk to the participant by their participation in the study Has received a COVID-19 vaccination within 1 week of day 1 of the study or for which the planned COVID-19 vaccinations would not be completed 1 week prior to day 1 of the study. NOTE: Other protocol defined inclusion / exclusion criteria apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm 1: Aspirin QD<br>Randomized 1:1:1 | Drug: Aspirin<br>* Administered orally once per day (QD)<br>|
| Experimental: Arm 2: Aspirin QD + rivaroxaban BID<br>Randomized 1:1:1 | Drug: Aspirin<br>* Administered orally once per day (QD)<br>Drug: rivaroxaban low dose<br>* Administered orally twice per day (BID)<br>|
| Experimental: Arm 3: Aspirin QD + rivaroxaban QD<br>Randomized 1:1:1 | Drug: Aspirin<br>* Administered orally once per day (QD)<br>Drug: rivaroxaban high dose<br>* Administered orally QD<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in fecal hemoglobin content as measured by HemoQuant during the second week of exposure to study medication | HemoQuant is a chemical laboratory test of fecal hemoglobin content. | Up to Week 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of bleeding events during the baseline period as compared to the treatment period |  | Up to week 4 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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No gastrointestinal (GI) disease, No risk factors for bleeding, Direct oral anticoagulant (DOAC), Fecal occult blood testing (FOBT)