Safety and Tolerability of Abelacimab (MAA868) vs. Rivaroxaban in Patients With Atrial Fibrillation

Phase 2

Active, not recruiting

• Conditions: Atrial Fibrillation (AF); Stroke
• Interventions: Biological: Abelacimab; Drug: Rivaroxaban

• Registration Number: NCT04755283
• Lead Sponsor: Anthos Therapeutics, Inc.

Brief Summary

The purpose of the ANT-006 study is to evaluate the bleeding profile of abelacimab relative to rivaroxaban in patients with atrial fibrillation (AF) at moderate-to-high risk of stroke.

Detailed Description

Not available

Study Timeline

• Study Start: 2021-02-02
• Study First Submitted: 2021-02-11
• Study First Submitted QC: 2021-02-11
• Study First Posted: 2021-02-16
• Primary Completion: 2024-02-15
• Disposition First Submitted: 2025-02-14
• Results First Submitted: 2025-04-03
• Results First Submitted QC: 2025-07-29
• Results First Posted: 2025-07-30
• Disposition First Posted: 2025-07-30
• Status Verified: 2025-08
• Last Update Submitted: 2025-08-21
• Last Update Posted: 2025-09-02
• Study Completion: 2028-12-29

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 1287

Inclusion Criteria

• Male and female patients ≥ 55 years old

• Patients with a history of atrial fibrillation (AF) or atrial flutter with planned indefinite anticoagulation

• Patients with a CHA2DS2-VASc of ≥4 OR a CHA2DS2-VASc of ≥3 with at least 1 of the following:

  1. Planned concomitant use of antiplatelet medication use (i.e., aspirin and/or P2Y12 inhibitor) for the duration of the trial
  2. Creatinine Clearance (CrCl) ≤50 ml/min by the Cockcroft-Gault equation

Exclusion Criteria

• History of hypersensitivity to any of the study drugs (including rivaroxaban) or its excipients, to drugs of similar chemical classes, or any contraindication listed in the label for rivaroxaban
• Patients with an intracranial or intraocular bleed within the 3 months prior to screening
• Clinically significant mitral stenosis (valve area <1.5 cm2)
• Mechanical heart valve or other indication for anticoagulation therapy other than atrial fibrillation (e.g., venous thromboembolism)
• Known presence of an atrial myxoma or left ventricular thrombus
• History of left atrial appendage closure or removal
• Active endocarditis

Other protocol defined Inclusion/Exclusion criteria may apply

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Abelacimab 90 mg (MAA868)	Abelacimab	Treatment group 1: Abelacimab low dose subcutaneous (s.c.) monthly Extension Treatment Group: Abelacimab high dose subcutaneous (s.c.) monthly
Rivaroxaban	Rivaroxaban	Treatment group 3: Rivaroxaban 20 mg by mouth; orally (p.o.) once per day with the evening meal Patients with a Creatinine Clearance (CrCl) ≤50 ml/min by the Cockcroft-Gault equation will have a dose adaptation to rivaroxaban 15 mg p.o. daily.
Abelacimab 150 mg (MAA868)	Abelacimab	Treatment group 2: Abelacimab high dose subcutaneous (s.c.) monthly Extension Treatment Group: Abelacimab high dose subcutaneous (s.c.) monthly

Primary Outcome Measures

Name	Time	Method
Incidence Rate of the First Occurrence of Composite of International Society on Thrombosis and Haemostasis (ISTH)-Defined Major Bleeding or Clinically Relevant Non-Major (CRNM) Bleeding Events	Assessed at every visit from randomization through the end of the randomized phase of the study, up to 33 months.	The number of participants experiencing the first occurrence of the composite of ISTH-defined major bleeding or CRNM bleeding events divided by the number of 100 person-years through the first event or end of treatment across all participants, is presented. For participants not experiencing events, person-years is calculated through the end of treatment during the randomized phase.

Secondary Outcome Measures

Name	Time	Method
Incidence Rate of the First Occurrence of ISTH-defined Major Bleeding Events	Assessed at every visit from randomization through the end of the randomized phase of the study, up to 33 months.	The number of participants experiencing the first occurrence of ISTH-defined major bleeding events divided by the number of 100 person-years through the first event or end of treatment across all participants, is presented. For participants not experiencing events, person-years is calculated through the end of treatment during the randomized phase.
Incidence Rate of the First Occurrence of ISTH-defined Major or CRNM or Minor Bleeding Events	Assessed at every visit from randomization through the end of the randomized phase of the study, up to 33 months.	The number of participants experiencing the first occurrence of the composite of ISTH-defined major or CRNM or minor bleeding events divided by the number of 100 person-years through the first event or end of treatment across all participants, is presented. For participants not experiencing events, person-years is calculated through the end of treatment during the randomized phase.

Trial Locations

Locations (3)

Anthos Investigative Site; 🇨🇳 Tiachung, TXG, Taiwan

Anthos Investigative Site (4002); 🇭🇺 Nyíregyháza, SZ, Hungary

Anthos Investigative Site (4003); 🇭🇺 Nyíregyháza, SZ, Hungary