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A Study to Investigate Andexanet Dosing and the Interaction Between Andexanet and Subsequent Enoxaparin in Healthy Participants

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

Status
Recruiting
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07312851
Enrollment
186
Registered
2025-12-31
Start date
2026-01-19
Completion date
2026-06-19
Last updated
2026-02-24

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

Conditions

Healthy Participants

Keywords

Posology, Re-anticoagulation, Pharmacodynamics, Life-threatening or uncontrolled bleeding, Thrombotic events, Factor Xa inhibitors

Brief summary

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.

Interventions

Andexanet alfa will be administered as an intravenous bolus followed by an infusion, however, in Module 3, only a bolus will be given.

DRUGRivaroxaban

Rivaroxaban will be administered as an oral tablet.

DRUGApixaban

Apixaban will be administered as an oral tablet.

DRUGEnoxaparin

Enoxaparin will be administered as a subcutaneous injection.

OTHERPlacebo

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.

Sponsors

AstraZeneca
Lead SponsorINDUSTRY
Parexel
CollaboratorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Masking description

Single blind

Intervention model description

4 Modules divided into 2 Parts

Eligibility

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

Inclusion criteria

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.

Design outcomes

Primary

MeasureTime frameDescription
Anti-Factor (F) Xa activityDay 1 post doseTo 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 activityDay 1 post doseTo 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 potentialDay 1 post doseTo 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 potentialDay 1 post doseTo 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 potentialDay 1 post doseTo 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 coagulationDay 1 post doseTo 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 coagulationDay 1 post doseTo 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 coagulationDay 1 post doseTo 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 dosingFrom Day 1 to Day 2To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured by chromogenic enzymatic anti-FXa activity assays.
Thrombin generation potential following enoxaparin dosingFrom Day 1 to Day 2To determine anticoagulation by enoxaparin at different time points after andexanet treatment measured as thrombin generation potential (including ETP).

Secondary

MeasureTime frameDescription
Module 3: Anti-FXa activityDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by chromogenic enzymatic anti-FXa activity assays.
Module 3: Change from baseline in anti-FXa activityDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by chromogenic enzymatic anti-FXa activity assays.
Module 3: Thrombin generation potentialDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Module 3: Change from baseline in thrombin generation potentialDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Module 3: Change from pre-DOAC in thrombin generation potentialDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by thrombin generation potential (including ETP).
Module 3: Time to onset of coagulationDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Module 3: Change from pre-DOAC in time to onset of coagulationDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Module 3: Change from baseline in time to onset of coagulationDay 1 post doseTo describe the PD effect of andexanet bolus by assessing reversal of rivaroxaban or apixaban anticoagulation, as measured by time to onset of coagulation.
Tissue factor pathway inhibitor (TFPI) activityUp to Day 4To 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.
Antithrombin 3 (AT3)Up to Day 4To 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).
Thrombinantithrombin complex (TAT)Up to Day 4To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of TAT.
Fibrin degradation fragment (D-dimer)Up to Day 4To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of D-dimer.
Prothrombin fragment 1+2 (F1+2)Up to Day 4To describe additional PD effects of andexanet doses by assessing reversal of rivaroxaban or apixaban anticoagulation on levels of F1+2.

Countries

Germany, United Kingdom

Contacts

CONTACTAstraZeneca Clinical Study Information Center
information.center@astrazeneca.com1-877-240-9479

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 25, 2026