Following Interim Analysis IDMEAC concluded:1-No safety concerns 2-Suspend enrolment: Futility based on treatment effect size at interim analysis. Enrollment was suspended on 22DEC25. Study was terminated FEB2026. Final analysis is planned in Q2 2026

This is a multicentre, prospective, randomised, double-blinded, group-sequential, parallel-group, adaptive design, phase 3 study to demonstrate the haemostatic efficacy and safety of four-factor prothrombin complex concentrate, OCTAPLEX, in patients with acute major bleeding on DOAC therapy with factor Xa inhibitor. Patients will be randomised 1:1 to either of two study groups: low-dose vs. high-dose OCTAPLEX.

Inclusion Criteria:

1. Patients on oral factor Xa inhibitor therapy and with known or suspected baseline anti-factor Xa activity of at least 100 ng/mL:

   - Patients who received or who are believed by the investigator to have received a dose of oral factor Xa inhibitor and who have a baseline anti- factor Xa activity of at least 100 ng/mL according to the locally available test (e.g., chromogenic assay) performed outside of the study as part of standard of care

   OR

   • Patients who received or who are believed by the investigator to have received their latest dose of oral factor Xa inhibitor (e.g., rivaroxaban ≥10 mg, apixaban ≥2.5 mg, edoxaban ≥30 mg) ≤8 hours prior to enrolment

   OR

   -Patients who received or who are believed by the investigator to have received their latest dose of oral factor Xa inhibitor (e.g., rivaroxaban ≥10 mg, apixaban ≥2.5 mg, edoxaban ≥30 mg) >8 hours prior to enrolment or at an unknown time, but for whom the investigator suspects a baseline anti- factor Xa activity of at least 100 ng/mL and assesses that the administration of OCTAPLEX is clinically indicated

2. Aged ≥18 years

3. Patients who have given written informed consent or for whom written informed consent has been obtained from the patient's legally authorised representative on their behalf -Wherever possible, prospective written informed consent will be obtained before enrolment from the patient or, if they are incapable of providing it, from their legally authorised representative

   -If prospective written informed consent is not possible, deferred consent procedures will be permitted outside the US if approved by the local ethics committee or otherwise permitted under local regulations

   -When deferred consent procedures are used outside the US, written informed consent should be obtained from the patient as soon as they recover the capacity to provide it, or otherwise from their legally authorised representative

4. Patients who have acute major bleeding defined as follows:

   • Bleeding that is life-threatening or uncontrolled, e.g., with signs or symptoms of haemodynamic compromise, such as severe hypotension, poor skin perfusion, or low cardiac output that cannot be otherwise explained

OR

- Symptomatic bleeding in critical organs (intracranial, intraspinal, intraocular, gastrointestinal, retroperitoneal, intra-articular, pericardial, or intramuscular with compartment syndrome)

OR

- Acute overt bleeding associated with a fall in haemoglobin (Hgb) level of ≥2 g/dL, OR a Hgb level ≤8 g/dL if no baseline Hgb level is available, OR in the opinion of the investigator that the patient's Hgb level will fall to ≤8 g/dL with resuscitation

Exclusion Criteria:

1. Patients with 'Do not resuscitate' (DNR) orders
2. Patients with acute trauma for which reversal of DOAC therapy with factor Xa inhibitor alone would not be expected to control the bleeding event
3. Hgb decrease without accompanying evidence of source of bleeding
4. Acute coronary syndrome, ischaemic stroke or venous thromboembolism (VTE) within the preceding 3 months
5. Patients with a history, within the last 3 months, of disseminated intravascular coagulation (DIC) or hyperfibrinolysis
6. Patients with a known congenital bleeding disorder
7. Known inhibitors to coagulation factors II, VII, IX, or X; heparin-induced, type II thrombocytopenia; or immunoglobulin A (IgA) deficiency with known antibodies against IgA
8. Known hypersensitivity to plasma-derived products or heparin
9. Patients who received haemostatic agents, including plasma, platelets, PCC, activated PCC (aPCC), recombinant factor VIIa, or recombinant factor Xa inactivated-zhzo (andexanet alfa), for the current bleeding event prior to enrolment (antifibrinolytic drugs and local haemostatic agents are allowed)
10. Patients who received ticlopidine within 14 days, prasugrel within 7 days, ticagrelor within 5 days, dipyridamole within 1 day or cangrelor within 1 hour preceding the bleeding event
11. Patients on enoxaparin therapy for thromboembolic prophylaxis
12. A score of less than 7 on the Glasgow Coma Scale in non-intubated patients or an estimated intracerebral haematoma volume of more than 60 mL. (Patients intubated or sedated at the time of screening may be enrolled if intubation or sedation were done for non-neurologic reasons)
13. Patients with expected survival of less than 24 hours, in the opinion of the investigator (in collaboration with other medical experts as appropriate per usual local practice)
14. Patients scheduled to undergo surgery in less than 12 hours, with the exception of minor surgeries and invasive procedures which are allowed for diagnostic or therapeutic reasons or if intended to address a second (non-index) bleeding event
15. Patients who are pregnant or breastfeeding at the time of enrollment
16. Patients previously enrolled in this study
17. Patients participating in another interventional clinical treatment study currently or during the past 1 month prior to study inclusion

Blinded