Pradeep Natarajan Shared New Article: Comparison Between Milvexian, Abelacimab and Enoxaparin
Pradeep Natarajan, Director, Preventive Cardiology at Massachusetts General Hospital, shared on LinkedIn:
“Milvexian (oral FXIa inhibitor bid) and Abelacimab (FXI mAb x1) both have been shown to ↓knee arthroplasty postop VTE vs enoxaparin (sc FXa & thrombin inhibitor).
In new RCT in same context, REGN7508Cat x1 was superior to enoxaparin sc daily but REGN9933A2 x1 was non-inferior. Bleeding rates were similar but postop anemia less common for both vs enopaxarin.

– REGN7508Cat blocks the catalytic domain of FXI, so it blocks FXIa activity & FXI activation by FXIIa *and* thrombin. This is generally similar to Abelacimab, which locks FXI in its inactive state.
– REGN9933A2 blocks the apple 2 domain of FXI, blocking FXIIa-mediated activation but permits thrombin-mediated activation. So it’s primarily a contact pathway FXI inhibitor.
The effect estimate for reduced VTE with REGN7508Cat vs enoxaparin seems similar for Abelacimab at the higher doses in ANT-005 TKA.
Milvexian BID had lower VTE rates relative to enoxaparin only at the highest studied dose of AXIOMATIC-TKR with similar bleeding rates.
The data continue to show that the deepest inhibition of FXI (Abelacimab, now REGN7508Cat) is most favorable for postop VTE prevention after knee arthroplasty.
This study effectively demonstrates that FXI activation by both FXIIa *and* thrombin play a role in postop VTE.
In exploratory analyses, REGN7508Cat had lower VTE rates vs apixaban (oral FXa inhibitor), which is exciting to see. Such a comparison was not performed in the Milvexian and Abelacimab postop VTE trials.”
Title: Efficacy and safety of REGN9933A2 and REGN7508Cat for preventing postoperative venous thromboembolism (ROXI-VTE-I and ROXI-VTE-II): two randomised, open-label, phase 2 trials
Authors: Jeffrey I Weitz, Aaron P Kithcart, Meagan P O’Brien, Oren Levy, Ethan Marin, Margaret Onisko, Kusha A Mohammadi, Dateng Li, Karoline A Meagher, Hannah H Chang, Benjamin A Olenchock, David E Gutstein, Annelise Segers, Robin S Roberts, Marc P Bonaca, Gary E Raskob

Read full paper here.
Stay informed with Hemostasis Today.
-
Sep 24, 2026, 06:52Gina Sado: Screening-Detected Atrial Fibrillation Carries High Risk of Heart Failure
-
Sep 24, 2026, 06:33Benjamin Vipler: Optimal Oral Anticoagulation Choice in Atrial Fibrillation and Advanced CKD
-
Sep 24, 2026, 06:08Christopher Salerno: AI-Powered At-Home Anemia Screening Advances Telehealth Access
-
Sep 24, 2026, 05:38Aya Qattan: When a Normal CBC Does Not Mean Normal Iron Status
-
Sep 24, 2026, 05:11Mastering Warm Autoimmune Hemolytic Anemia Diagnosis and Practice – ASH Education
-
Sep 23, 2026, 16:04Monia Ezzalfani: Advancing Patient-Centered Care in Hemophilia A and B
-
Sep 23, 2026, 15:49Bilge Başak: How Activated PRP Modulates Osteoarthritic Chondrocyte Function
-
Sep 23, 2026, 14:50Mbonjo Bitsie Dora: Strengthening Sickle Cell Care Through Education, Awareness and Innovation
-
Sep 23, 2026, 13:58The New B12 Diagnostic Algorithm: From Serum Cobalamin to Functional Deficiency