Conditions: Atrial Fibrillation
Keywords: Atrial Fibrillation Betrixaban Factor Xa inhibitor Warfarin
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 508
Healthy volunteers: no

Brief summary:
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.

Detailed description:
To assess the safety and tolerability of betrixaban at doses of 40 mg, 60 mg and 80 mg given orally once a day for at least 3 months compared to dose-adjusted warfarin in patients with non-valvular atrial fibrillation (AF).

This is a Phase 2, exploratory, randomized, parallel group, multicenter, active comparator, dose finding study of patients with documented non-valvular AF. Patients will be randomized (1:1:1:1) to 1 of 4 treatment groups (approximately 125 patients per group) using an interactive voice response system (IVRS). A dynamic randomization will be used to balance patients by country, concurrent aspirin use (yes or no) and antecedent warfarin (yes or no). The study will be open label for randomization to warfarin versus betrixaban, but the three daily doses of betrixaban, 40 mg, 60 mg or 80 mg, will be double-blind (identical capsules for all three dose levels). The warfarin-treated patients will be managed according to each center's usual clinical routine with INR monitoring and dose-adjustments in order to maintain a target INR of 2.0 to 3.0 at maximum intervals of four weeks. No loading doses or dose titrations will be used for betrixaban. The betrixaban dose should be ingested in the evening (e.g. at bedtime), preferably at least 2 hours after the evening meal. Note: acenocumerol may be substituted for warfarin as indicated by local practice.

Arms:
arm 1: Betrixaban, 40 mg, orally, once daily for at least 3 months. arm 2: Betrixaban, 60 mg, orally, once daily for at least 3 months arm 3: Betrixaban, 80 mg, orally, once daily for at least 3 months arm 4: Warfarin will be prescribed by investigators according to the standard of care.

Interventions: intervention 1: betrixaban intervention 2: Warfarin
Intervention descriptions: intervention 1: orally, once daily for at least 3 months intervention 2: Warfarin will be prescribed by the investigator according to the standard of care.

Protocol document: