Healthy ParticipantsPhase 1NCT07312851
A Study to Investigate Andexanet Dosing and the Interaction Between Andexanet and Subsequent Enoxaparin in Healthy Participants
A Phase 1 study testing Andexanet alfa, Rivaroxaban and Apixaban in people with Healthy Participants, run by AstraZeneca at 2 sites in 2 countries.
Trial summary
The purpose of this study is to characterize andexanet posology and interaction between andexanet and enoxaparin post infusion in healthy participants. Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Participants
- What is being tested?
- Andexanet alfa, Rivaroxaban and Apixaban
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 191 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 19 Jan 2026to 22 Jun 2026
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Main Inclusion Criteria:
- All females must have a negative pregnancy test at the Screening Visit.
- Females of childbearing potential must not be lactating and if heterosexually active must agree to use an approved method of highly effective contraception.
- Sexually active fertile male participants with partners of childbearing potential must adhere to the study specific contraception methods.
- Have a Body Mass Index (BMI) between 18.5 and 30.0 kg/m2 (both inclusive) and weigh at least 60 kg.
- Agree to abstain from alcohol consumption or smoking for the duration of the residential period, and from the use of drugs of abuse for the duration of the study.
- Be in good health and agree to have any dietary or nutritional supplements, if needed.
Main Exclusion Criteria:
- History of any clinically significant disease or disorder which may either put the participant at risk because of participation in the study or influence the results or the participant's ability to participate in the study.
- History or presence of gastrointestinal, hepatic, or renal disease or any other condition known to interfere with absorption, distribution, metabolism, or excretion of drugs.
- History of abnormal bleeding or bleeding disorders (eg, hemophilia, von Willebrand disease), signs or symptoms of active bleeding, or risk factors for bleeding.
- History of adult asthma or chronic obstructive pulmonary disease or current regular or as needed use of inhaled medications.
- Family history of or known risk factors for a hypercoagulable or thrombotic condition or thrombotic event, such as anti-phospholipid syndrome; Factor V Leiden carrier or homozygote; Protein C, S, or AT3 activity below the normal range.
- Past or current medical history of thrombosis, any sign or symptom that suggests an increased risk of a systemic thrombotic condition, or recent events that may increase risk of thrombosis.
- Any medical or surgical conditions which may impair drug (anticoagulant or andexanet) uptake, metabolism, or excretion.
- An absolute or relative contraindication to anticoagulation or treatment with apixaban, rivaroxaban or enoxaparin.
- Any clinically significant illness or medical procedure within 4 weeks of the first administration of study intervention.
- Any clinically significant abnormalities in clinical chemistry, hematology, coagulation or urinalysis results
- Any positive result on Screening for serum hepatitis B surface antigen (HBsAg) OR anti-hepatitis B core (HBc) antibody, indicative of active hepatitis B (ie, participants with positive anti-HBc antibody result are acceptable if anti-HBc IgM antibodies are negative), anti- hepatitis C virus (HCV) or human immunodeficiency virus (HIV).
- History of severe allergy/hypersensitivity or ongoing clinically significant allergy/hypersensitivity, including heparin-induced thrombocytopenia, or history of hypersensitivity to drugs with a similar chemical structure or class to andexanet, apixaban, rivaroxaban, or enoxaparin or any of the vehicle ingredients.
- Use of any prescribed or nonprescribed medication including antacids, analgesics (other than paracetamol/acetaminophen), herbal remedies, intake of > 3 × daily recommended levels of vitamins and minerals during the 2 weeks prior to the first administration of study intervention or longer (> 5 half-lives) if the medication has a long half-life. The participant has taken (by any route) one or more doses of aspirin (including baby aspirin), salicylate or subsalicylate, other antiplatelet drugs (eg, ticagrelor, clopidogrel, ticlopidine), non-steroidal anti-inflammatory drugs, fibrinolytic, or any anticoagulant within 7 days prior to Admission or is anticipated to require such drugs during the study. The participant has been receiving (by any route) hormonal contraception, postmenopausal HRT (including over-the-counter products), or testosterone during the 4 weeks prior to Admission or is anticipated to require such drugs during the study.
- Has received another new chemical entity (defined as a compound which has not been approved for marketing) within 30 days or 5 half-lives (whichever is longest) of Admission.
- Participants who have previously received andexanet.
Trial locations and contacts
2 sites in 2 countries.
2 sites in 2 countries
About this study
Official title: A Phase I, Randomized, Single-blind, Placebo-controlled Study to Further Characterize Andexanet Posology and Assess the Interaction Between Andexanet and Subsequent Enoxaparin in Healthy Participants
The purpose of this study is to characterize andexanet posology and interaction between andexanet and enoxaparin post infusion in healthy participants.
Read the detailed description
This is a single-blind, placebo-controlled study. The study has 4 modules, which is then divided into 2 parts. Part A of the study will focus on further characterization of andexanet posology and Part B of the study will evaluate a re-institution of anticoagulation with enoxaparin.
Module 1, 2 and 4 - rivaroxaban, apixaban and enoxaparin: These modules are designed to determine the pharmacodynamic (PD) effect of andexanet by assessing its reversal effects on rivaroxaban and apixaban anticoagulation, or assessing its effects in the absence of anticoagulants, and to identify the time interval after andexanet administration at which andexanet shows no impact on enoxaparin.
Module 3 - rivaroxaban and apixaban: This Module is designed to determine the PD effect of bolus only andexanet by assessing its reversal effect on rivaroxaban and apixaban anticoagulation.
All the Modules will comprise:
- A Screening/Enrollment Period of maximum 28 days.
- An in-house stay comprising of a safety baseline lab period (Day -3 to Day -1)
- Treatment period (Day 1 to Day 2)
- Safety follow-up period (Day 3 to Day 5)
- A final Follow-up Visit within 30 days (+7 days) after the last andexanet/placebo administration.
- Conditions
- Healthy Participants
- Being tested
- Andexanet alfa, Rivaroxaban, Apixaban, Enoxaparin, Placebo
- Keywords
- Posology, Re-anticoagulation, Pharmacodynamics, Life-threatening or uncontrolled bleeding, Thrombotic events, Factor Xa inhibitors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Andexanet alfaDrug
Andexanet alfa will be administered as an intravenous bolus followed by an infusion, however, in Module 3, only a bolus will be given.
RivaroxabanDrug
Rivaroxaban will be administered as an oral tablet.
ApixabanDrug
Apixaban will be administered as an oral tablet.
EnoxaparinDrug
Enoxaparin will be administered as a subcutaneous injection.
PlaceboOther
Placebo will replace andexanet and be given as an IV bolus plus infusion in Modules 1 and 2; in Module 3, placebo will be IV bolus only. In Module 4, an oral placebo tablet will replace rivaroxaban and apixaban.
| Study group | Role | What they receive |
|---|---|---|
| Module 1: Rivaroxaban + Andexanet (dose A) | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose A) dosing, the participants will receive an additional dose of rivaroxaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. Receives: Drug: Andexanet alfa; Drug: Rivaroxaban; Drug: Enoxaparin |
| Module 1: Rivaroxaban + Andexanet (dose B) | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of rivaroxaban. Receives: Drug: Andexanet alfa; Drug: Rivaroxaban |
| Module 1: Rivaroxaban + Andexanet (dose C) | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional dose of rivaroxaban. Receives: Drug: Andexanet alfa; Drug: Rivaroxaban |
| Module 1: Rivaroxaban + Placebo | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of rivaroxaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after placebo administration. Receives: Drug: Rivaroxaban; Drug: Enoxaparin; Other: Placebo |
| Module 2: Apixaban + Andexanet (dose B) | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of apixaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. Receives: Drug: Andexanet alfa; Drug: Apixaban; Drug: Enoxaparin |
| Module 2: Apixaban + Andexanet (dose C) | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional dose of apixaban. Receives: Drug: Andexanet alfa; Drug: Apixaban |
| Module 2: Apixaban + Andexanet (dose D) | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose D) dosing, the participants will receive an additional dose of apixaban. Receives: Drug: Andexanet alfa; Drug: Apixaban |
| Module 2: Apixaban + Placebo | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of apixaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after placebo administration. Receives: Drug: Apixaban; Drug: Enoxaparin; Other: Placebo |
| Module 3: Rivaroxaban + Andexanet (Dose A) | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose A) dosing, the participants will receive an additional dose of rivaroxaban. Receives: Drug: Andexanet alfa; Drug: Rivaroxaban |
| Module 3: Apixaban + Andexanet (Dose B) | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of apixaban. Receives: Drug: Andexanet alfa; Drug: Apixaban |
| Module 3: Rivaroxaban + Placebo | Experimental | Participants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose A of andexanet) dosing, the participants will receive an additional dose of rivaroxaban. Receives: Drug: Rivaroxaban; Other: Placebo |
| Module 3: Apixaban + Placebo | Experimental | Participants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of apixaban. Receives: Drug: Apixaban; Other: Placebo |
| Module 4: Placebo + Andexanet (dose C) | Experimental | Participants will receive daily dose of one placebo tablet from Day -3 to Day -1. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional placebo tablet. Receives: Drug: Andexanet alfa; Other: Placebo |
| Module 4: Placebo + Andexanet (dose B) | Experimental | Participants will receive daily dose of one placebo tablet from Day -3 to Day -1. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional placebo tablet. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. Receives: Drug: Andexanet alfa; Drug: Enoxaparin; Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Anti-Factor (F) Xa activity
To determine the pharmacodynamic (PD) effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured by chromogenic enzymatic anti-FXa activity assays.
Measured: Day 1 post dose
Change from baseline in anti-FXa activity
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured by chromogenic enzymatic anti-FXa activity assays.
Measured: Day 1 post dose
Thrombin generation potential
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including Endogenous Thrombin Potential [ETP]).
Measured: Day 1 post dose
Change from pre-direct oral anticoagulants (DOAC) in thrombin generation potential
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including ETP).
Measured: Day 1 post dose
Change from baseline in thrombin generation potential
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including ETP).
Measured: Day 1 post dose
Time to onset of coagulation
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Measured: Day 1 post dose
Change from pre-DOAC in time to onset of coagulation
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Measured: Day 1 post dose
Change from baseline in time to onset of coagulation
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Measured: Day 1 post dose
Anti-FXa activity following enoxaparin dosing
To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured by chromogenic enzymatic anti-FXa activity assays.
Measured: From Day 1 to Day 2
Thrombin generation potential following enoxaparin dosing
To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured as thrombin generation potential (including ETP).
Measured: From Day 1 to Day 2
Secondary outcomes (13)
Module 3: Anti-FXa activity
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by chromogenic enzymatic anti-FXa activity assays.
Measured: Day 1 post dose
Module 3: Change from baseline in anti-FXa activity
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by chromogenic enzymatic anti-FXa activity assays.
Measured: Day 1 post dose
Module 3: Thrombin generation potential
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Measured: Day 1 post dose
Module 3: Change from baseline in thrombin generation potential
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Measured: Day 1 post dose
Module 3: Change from pre-DOAC in thrombin generation potential
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Measured: Day 1 post dose
Module 3: Time to onset of coagulation
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Measured: Day 1 post dose
Module 3: Change from pre-DOAC in time to onset of coagulation
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Measured: Day 1 post dose
Module 3: Change from baseline in time to onset of coagulation
To describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Measured: Day 1 post dose
Tissue factor pathway inhibitor (TFPI) activity
To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of TFPI activity measured by enzymatic TFPI activity assay.
Measured: Up to Day 4
Antithrombin 3 (AT3)
To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of AT3 measured by an AT3 enzyme-linked immunosorbent assay (ELISA).
Measured: Up to Day 4
Thrombinantithrombin complex (TAT)
To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of TAT.
Measured: Up to Day 4
Fibrin degradation fragment (D-dimer)
To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of D-dimer.
Measured: Up to Day 4
Prothrombin fragment 1+2 (F1+2)
To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of F1+2.
Measured: Up to Day 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2025
- Study start19 Jan 2026
- Primary completion22 Jun 2026
- Study completion22 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy ParticipantsStudies of the same condition, open and under way.
- More trials run by AstraZenecaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 4 Modules divided into 2 Parts
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 191 participants (actual)
Sponsor and investigators
- Lead sponsor
- AstraZeneca
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Parexel
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07312851
- Sponsor's protocol ID
- D9609C00001
- Other IDs
- 2025-522513-30-00, 2025
- Status last verified
- Jul 2026
- First submitted
- 27 Nov 2025
- Last updated
- 9 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.
Study at a glance
From the registry record, last updated by the sponsor on 9 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I, Randomized, Single-blind, Placebo-controlled Study to Further Characterize Andexanet Posology and Assess the Interaction Between Andexanet and Subsequent Enoxaparin in Healthy Participants
- ClinicalTrials.gov ID
- NCT07312851
- Acronym / sponsor ID
- D9609C00001
- Conditions
- Healthy Participants
- Keywords
- Posology, Re-anticoagulation, Pharmacodynamics, Life-threatening or uncontrolled bleeding, Thrombotic events, Factor Xa inhibitors
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 191 participants (actual)
- Lead sponsor
- AstraZenecaIndustry (pharma, biotech, devices)
- Collaborators
- Parexel
- Study start
- 19 Jan 2026 (actual)
- Primary completion
- 22 Jun 2026 (actual)
- Study completion
- 22 Jun 2026 (actual)
- First posted
- 31 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to characterize andexanet posology and interaction between andexanet and enoxaparin post infusion in healthy participants.
Detailed description
This is a single-blind, placebo-controlled study. The study has 4 modules, which is then divided into 2 parts. Part A of the study will focus on further characterization of andexanet posology and Part B of the study will evaluate a re-institution of anticoagulation with enoxaparin.
Module 1, 2 and 4 - rivaroxaban, apixaban and enoxaparin: These modules are designed to determine the pharmacodynamic (PD) effect of andexanet by assessing its reversal effects on rivaroxaban and apixaban anticoagulation, or assessing its effects in the absence of anticoagulants, and to identify the time interval after andexanet administration at which andexanet shows no impact on enoxaparin.
Module 3 - rivaroxaban and apixaban: This Module is designed to determine the PD effect of bolus only andexanet by assessing its reversal effect on rivaroxaban and apixaban anticoagulation.
All the Modules will comprise:
- A Screening/Enrollment Period of maximum 28 days.
- An in-house stay comprising of a safety baseline lab period (Day -3 to Day -1)
- Treatment period (Day 1 to Day 2)
- Safety follow-up period (Day 3 to Day 5)
- A final Follow-up Visit within 30 days (+7 days) after the last andexanet/placebo administration.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 14
- Model description
- 4 Modules divided into 2 Parts
| Arm | Type | Receives |
|---|---|---|
| Module 1: Rivaroxaban + Andexanet (dose A) | Experimental | Drug: Andexanet alfa, Drug: Rivaroxaban, Drug: EnoxaparinParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose A) dosing, the participants will receive an additional dose of rivaroxaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. |
| Module 1: Rivaroxaban + Andexanet (dose B) | Experimental | Drug: Andexanet alfa, Drug: RivaroxabanParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of rivaroxaban. |
| Module 1: Rivaroxaban + Andexanet (dose C) | Experimental | Drug: Andexanet alfa, Drug: RivaroxabanParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional dose of rivaroxaban. |
| Module 1: Rivaroxaban + Placebo | Experimental | Drug: Rivaroxaban, Drug: Enoxaparin, Other: PlaceboParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of rivaroxaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after placebo administration. |
| Module 2: Apixaban + Andexanet (dose B) | Experimental | Drug: Andexanet alfa, Drug: Apixaban, Drug: EnoxaparinParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of apixaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. |
| Module 2: Apixaban + Andexanet (dose C) | Experimental | Drug: Andexanet alfa, Drug: ApixabanParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional dose of apixaban. |
| Module 2: Apixaban + Andexanet (dose D) | Experimental | Drug: Andexanet alfa, Drug: ApixabanParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose D) dosing, the participants will receive an additional dose of apixaban. |
| Module 2: Apixaban + Placebo | Experimental | Drug: Apixaban, Drug: Enoxaparin, Other: PlaceboParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of apixaban. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after placebo administration. |
| Module 3: Rivaroxaban + Andexanet (Dose A) | Experimental | Drug: Andexanet alfa, Drug: RivaroxabanParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose A) dosing, the participants will receive an additional dose of rivaroxaban. |
| Module 3: Apixaban + Andexanet (Dose B) | Experimental | Drug: Andexanet alfa, Drug: ApixabanParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional dose of apixaban. |
| Module 3: Rivaroxaban + Placebo | Experimental | Drug: Rivaroxaban, Other: PlaceboParticipants will receive once daily dose of 20 mg rivaroxaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose A of andexanet) dosing, the participants will receive an additional dose of rivaroxaban. |
| Module 3: Apixaban + Placebo | Experimental | Drug: Apixaban, Other: PlaceboParticipants will receive twice daily dose of 5 mg apixaban from Day -3 to Day -1 to achieve steady state plasma levels. On Day 1, approximately 3 hours before placebo (equivalent to dose B of andexanet) dosing, the participants will receive an additional dose of apixaban. |
| Module 4: Placebo + Andexanet (dose C) | Experimental | Drug: Andexanet alfa, Other: PlaceboParticipants will receive daily dose of one placebo tablet from Day -3 to Day -1. On Day 1, approximately 3 hours before andexanet (dose C) dosing, the participants will receive an additional placebo tablet. |
| Module 4: Placebo + Andexanet (dose B) | Experimental | Drug: Andexanet alfa, Drug: Enoxaparin, Other: PlaceboParticipants will receive daily dose of one placebo tablet from Day -3 to Day -1. On Day 1, approximately 3 hours before andexanet (dose B) dosing, the participants will receive an additional placebo tablet. Participants will be further allocated to groups to receive doses of enoxaparin at different time points after the end of andexanet bolus. |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Andexanet alfaAndexanet alfa will be administered as an intravenous bolus followed by an infusion, however, in Module 3, only a bolus will be given. | Drug | Module 1: Rivaroxaban + Andexanet (dose A), Module 1: Rivaroxaban + Andexanet (dose B), Module 1: Rivaroxaban + Andexanet (dose C), Module 2: Apixaban + Andexanet (dose B), Module 2: Apixaban + Andexanet (dose C), Module 2: Apixaban + Andexanet (dose D), Module 3: Apixaban + Andexanet (Dose B), Module 3: Rivaroxaban + Andexanet (Dose A), Module 4: Placebo + Andexanet (dose B), Module 4: Placebo + Andexanet (dose C) |
| RivaroxabanRivaroxaban will be administered as an oral tablet. | Drug | Module 1: Rivaroxaban + Andexanet (dose A), Module 1: Rivaroxaban + Andexanet (dose B), Module 1: Rivaroxaban + Andexanet (dose C), Module 1: Rivaroxaban + Placebo, Module 3: Rivaroxaban + Andexanet (Dose A), Module 3: Rivaroxaban + Placebo |
| ApixabanApixaban will be administered as an oral tablet. | Drug | Module 2: Apixaban + Andexanet (dose B), Module 2: Apixaban + Andexanet (dose C), Module 2: Apixaban + Andexanet (dose D), Module 2: Apixaban + Placebo, Module 3: Apixaban + Andexanet (Dose B), Module 3: Apixaban + Placebo |
| EnoxaparinEnoxaparin will be administered as a subcutaneous injection. | Drug | Module 1: Rivaroxaban + Andexanet (dose A), Module 1: Rivaroxaban + Placebo, Module 2: Apixaban + Andexanet (dose B), Module 2: Apixaban + Placebo, Module 4: Placebo + Andexanet (dose B) |
| PlaceboPlacebo will replace andexanet and be given as an IV bolus plus infusion in Modules 1 and 2; in Module 3, placebo will be IV bolus only. In Module 4, an oral placebo tablet will replace rivaroxaban and apixaban. | Other | Module 1: Rivaroxaban + Placebo, Module 2: Apixaban + Placebo, Module 3: Apixaban + Placebo, Module 3: Rivaroxaban + Placebo, Module 4: Placebo + Andexanet (dose B), Module 4: Placebo + Andexanet (dose C) |
Primary outcome
Anti-Factor (F) Xa activity
Time frame: Day 1 post dose
To determine the pharmacodynamic (PD) effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured by chromogenic enzymatic anti-FXa activity assays.
Change from baseline in anti-FXa activity
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured by chromogenic enzymatic anti-FXa activity assays.
Thrombin generation potential
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including Endogenous Thrombin Potential [ETP]).
Change from pre-direct oral anticoagulants (DOAC) in thrombin generation potential
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including ETP).
Change from baseline in thrombin generation potential
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as thrombin generation potential (including ETP).
Time to onset of coagulation
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Change from pre-DOAC in time to onset of coagulation
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Change from baseline in time to onset of coagulation
Time frame: Day 1 post dose
To determine the PD effect of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation measured as time to onset of coagulation.
Anti-FXa activity following enoxaparin dosing
Time frame: From Day 1 to Day 2
To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured by chromogenic enzymatic anti-FXa activity assays.
Thrombin generation potential following enoxaparin dosing
Time frame: From Day 1 to Day 2
To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured as thrombin generation potential (including ETP).
13 secondary outcomes
Module 3: Anti-FXa activity
Time frame: Day 1 post dose
Module 3: Change from baseline in anti-FXa activity
Time frame: Day 1 post dose
Module 3: Thrombin generation potential
Time frame: Day 1 post dose
Module 3: Change from baseline in thrombin generation potential
Time frame: Day 1 post dose
Module 3: Change from pre-DOAC in thrombin generation potential
Time frame: Day 1 post dose
Module 3: Time to onset of coagulation
Time frame: Day 1 post dose
Module 3: Change from pre-DOAC in time to onset of coagulation
Time frame: Day 1 post dose
Module 3: Change from baseline in time to onset of coagulation
Time frame: Day 1 post dose
Tissue factor pathway inhibitor (TFPI) activity
Time frame: Up to Day 4
Antithrombin 3 (AT3)
Time frame: Up to Day 4
Thrombinantithrombin complex (TAT)
Time frame: Up to Day 4
Fibrin degradation fragment (D-dimer)
Time frame: Up to Day 4
Prothrombin fragment 1+2 (F1+2)
Time frame: Up to Day 4
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jul 2026.
- Individual participant dataSharing planned: Yes. Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Andexanet alfa, Rivaroxaban and Apixaban in people with Healthy Participants, run by AstraZeneca at 2 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Anti-Factor (F) Xa activity (time frame: Day 1 post dose). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jul 2026; AzTrials last refreshed its copy on 1 Nov 2026.