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A Study of Andexanet Alfa in Patients Requiring Urgent Surgery or Procedure

A Randomized Study of Andexanet Alfa Compared to Usual Care in Patients Receiving a Factor Xa Inhibitor Who Require Urgent Surgery or Procedure (ANNEXA-RS)

Status
Withdrawn
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05926349
Acronym
ANNEXA-RS
Enrollment
0
Registered
2023-07-03
Start date
2024-08-02
Completion date
2027-09-07
Last updated
2024-10-26

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

Conditions

Urgent Surgery

Keywords

Andexanet alfa, Blood Thinners

Brief summary

The study will aim to find out if the drug andexanet alfa is safe and effective in preventing major bleeding during urgent surgery or invasive procedures. The study will compare the use of andexanet alfa to the usual care given at the study center.

Detailed description

This study will be an open-label, randomised, controlled, prospective, multicenter study. The study will include patients requiring urgent surgery or procedure that needs to be performed within 15 hours of the last dose of blood-thinning drug (direct oral activated Factor X (FXa) inhibitor). The study will comprise of the following periods: * Screening, followed by surgery or procedure and study intervention. * Follow-up period: there will be four follow-up visits over a duration of approximately 30 days. * Follow-up visit for patients with positive anti-andexanet alfa antibody test: patients with a positive anti-andexanet alfa antibody response at day 30 will have a follow-up anti-andexanet alfa antibody test approximately 120 days post-surgery or procedure. Patients will be randomised in the ratio of 1:1 to receive either andexanet alfa or usual care.

Interventions

Andexanet is a recombinant version of human FXa

DRUGUsual Care

As per the label of the chosen usual care product(s) and/or usual care standards.

Sponsors

AstraZeneca
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 130 Years
Healthy volunteers
No

Inclusion criteria

* The patient requires, in the opinion of the Investigator, urgent surgery or procedure and requires reversal of direct oral FXa inhibition. * The patient requires urgent surgery or procedure within 12 hours of informed consent. * The patient requires urgent surgery or procedure that is expected to be associated with a high risk of bleeding or bleeding to occur into a critical organ. * The patient has taken an oral FXa inhibitor (such as apixaban, rivaroxaban, or edoxaban) within 15 hours or more, prior to start of surgery or procedure. * Female patients of childbearing potential must have a negative pregnancy test at Screening. * Willingness to use highly effective methods of contraception (for male and female patients who are fertile).

Exclusion criteria

* The patient requires surgeries or procedures that have a very low chance of causing significant, uncontrollable bleeding, such as small skin procedures, cataract surgery, and minor dental procedures. * The patient has acute life-threatening bleeding at the time of Screening. * The patient will undergo a surgery or procedure which will require the use of heparin. * Patient who is not expected to live for more than three months due to other health problems or has specifically requested not to be resuscitated if their heart stops beating. * Prior to screening, the patient had either experienced low platelet count due to heparin use with or without blood clots or had a genetic condition that affects blood clotting. * Patient has acute decompensated heart failure, cardiogenic shock, sepsis, or septic shock at the time of Screening. * Patient has history of heparin-induced thrombocytopenia (with or without thrombosis) or inherited coagulopathy (eg, anti-thrombin III deficiency, anti-phospholipid antibody syndrome, protein C/S deficiency, Factor V Leiden) at the time of Screening. * Previously diagnosed with a bleeding disorder (eg, platelet function disorder, hemophilia, Von Willebrand disease, or coagulation factor deficiency). * Prior known hypersensitivity to andexanet alfa. * Use of andexanet alfa 30 days prior to Screening. * Patient diagnosed with dementia. * Any prohibited medication as determined in the study.

Design outcomes

Primary

MeasureTime frameDescription
Number of patients achieving effective intraoperative hemostasisFrom start to the end of surgery or procedure on Day 0Intraoperative hemostasis will be assessed according to the categories as per 4-point hemostasis scale: Excellent - Normal hemostasis, Good - Mildly abnormal hemostasis (eg. slight oozing from surgical wounds), Moderate - Moderate abnormality in intraprocedural hemostasis (eg. controllable bleeding), Poor - Severe hemostatic abnormality (eg. severe refractory hemorrhage). Hemostasis will be considered to be effective if the intraoperative hemostasis category is 'excellent' or 'good', and ineffective if the intraoperative hemostasis category is 'moderate' or 'poor'.

Secondary

MeasureTime frameDescription
Change from Baseline in anti-FXa activity measured through blood samplesBaseline to start of surgery or procedureThe ability of andexanet alfa to rapidly reverse the anticoagulation effect of FXa inhibitors by reduction of anti-FXa activity when compared to usual care.

Other

MeasureTime frameDescription
Number of patients with adverse eventsScreening (Day -1 to Day 0) until follow-up visit (Day 30 or Day 120)Safety and tolerability will be evaluated in terms of adverse events and serious adverse events.

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026