NCT00742859 (EXPLORE-Xa) is a Phase 2 clinical trial of betrixaban in Atrial Fibrillation, sponsored by Portola Pharmaceuticals.

Who is sponsoring NCT00742859?

NCT00742859 is sponsored by Portola Pharmaceuticals.

What drugs are being tested in NCT00742859?

Interventions in NCT00742859: betrixaban, Warfarin.

What condition does NCT00742859 study?

NCT00742859 studies Atrial Fibrillation.

Is NCT00742859 still recruiting?

NCT00742859 is currently completed. Last updated 3 August 2023.

Are results published for NCT00742859?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2023-08-03 · How we verify

NCT00742859: EXPLORE-Xa

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

A Phase 2, Randomized, Parallel Group, Dose-Finding, Multicenter, Multinational Study of the Safety, Tolerability and Pilot Efficacy of Three Blinded Doses of the Oral Factor Xa Inhibitor Betrixaban Compared With Open-Label Dose-Adjusted Warfarin in Patients With Non-Valvular Atrial Fibrillation (EXPLORE Xa)

Completed Phase 2 Results posted Last updated 3 August 2023

What this trial tests

Phase 2 trial testing betrixaban in Atrial Fibrillation in 508 participants. Completed in 1 November 2009.

Timeline

1 October 2008

Primary endpoint
1 August 2009

1 November 2009

Quick facts

Lead sponsor	Portola Pharmaceuticals
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	quadruple
Primary purpose	treatment
Enrollment	508
Start date	1 October 2008
Primary completion	1 August 2009
Estimated completion	1 November 2009
Sites	21 locations across United States, Canada

Drugs / interventions tested

betrixaban (BETRIXABAN) — full drug profile →
Warfarin (warfarin) — full drug profile →

Conditions studied

Atrial Fibrillation — all drugs for Atrial Fibrillation →

Sponsor

Portola Pharmaceuticals — full company profile →

Who can join

18 and older, any sex, with Atrial Fibrillation. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

Exposure-adjusted Incidence Rate of Major or Clinically Relevant Non-major Bleeding Episode
Time frame: A maximum of 1 year
The primary endpoint is the time to the first occurrence of major or clinically relevant non-major bleeding. This was presented as the exposure adjusted incidence rate which was calculated as number of subjects experiencing the event divided by total person years across all subjects, where if a patient experiencing the event, year was from first dose date to the first occurrence of the event, and

Sponsor's own description

Prevention of stroke in patients with atrial fibrillation (AF). Hypothesis: In patients with non-valvular AF, orally administered betrixaban will provide similar or better efficacy and safety than warfarin and it will offer the advantage of not requiring dose adjustments due to international normalized ratios (INRs) outside the target range of 2.0 to 3.0 and a more consistent level of anticoagulation over time.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

Review of atrial fibrillation outcome trials of oral anticoagulant and antiplatelet agents.
Bassand JP. · · 2012 · cited 24× · PMID 22355190 · DOI 10.1093/europace/eur263
New anticoagulants - promising and failed developments.
Harenberg J, Marx S, Krejczy M, Wehling M. · · 2012 · cited 16× · PMID 21740405 · DOI 10.1111/j.1476-5381.2011.01578.x

Verify or expand the search:

Other recruiting trials for Atrial Fibrillation

Currently open trials in the same condition.

NCT07429214 — A Study of VARIPULSE Catheter and TRUPULSE Generator With VARIPULSE Pro Software in Participants With PAF or PsAF · NA · recruiting
NCT07271238 — Feasibility Study on the VERAFEYE Imaging and Navigation System for Guided Catheter Ablation Procedures · NA · recruiting
NCT07388108 — Atrial Dyssynchrony to Predict Arrhythmias in the Postoperative Setting of Cardiovascular Surgery. · recruiting
NCT07428967 — AV Node Ablation and CONDUCTion System Pacing for Atrial Fibrillation With Preserved Left Ventricular Function · NA · recruiting
NCT06650995 — AlEX-DHF: Ablation and Exercise in Diastolic Heart Failure · NA · recruiting

Other Portola Pharmaceuticals trials

Trials by the same sponsor.

NCT04021082 — CELTIC-1: A Phase 2B Study of Cerdulatinib in Patients With Relapsed/Refractory Peripheral T-Cell Lymphoma (PTCL) · Phase 2, PHASE3 · withdrawn
NCT03397888 — The Effect o f Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of Betrixiban, an Oral FXa Antagonist · Phase 1 · completed
NCT03310021 — A Healthy Volunteer Pharmacokinetics (PK)/Pharmacodynamics (PD), Safety and Tolerability Study of Andexanet in Healthy J · Phase 2 · completed
NCT03083704 — A Healthy Volunteer PK/PD, Safety and Tolerability Study of Second Generation Andexanet Alfa · Phase 1 · completed
NCT03330457 — A Healthy Volunteer PK/PD, Safety and Tolerability Study of Andexanet After Betrixaban Dosing · Phase 2 · terminated

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT00742859 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Portola Pharmaceuticals
Last refreshed: 3 August 2023

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT00742859.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing