BAY1831865 / Aronora, Bayer, Ligand - LARVOL DELTA

Selective Bypassing Approaches for Long-Acting Factor XI Antibody Therapeutics (ISTH 2026) - "BAY1831865) and gruticibart (AB023 A2 ) are therapeutic FXI antibodies currently in clinical phase 1 and phase 2 development, respectively. These results suggest that selective neutralization of a FXI inhibitor may be a safer reversal strategy to one that mimics FXI replacement. DOI*10.1016/j.rpth.2026.105547"

Cardiovascular • Hematological Disorders • Thrombosis

Evaluating reversal strategies for long-acting factor XI antibodies: RFVIIa®, FEIBA®, Kcentra®, novel FXI mutants, and an anti-idiotypic antibody (ASH 2025) - "BAY1831865), and theactive site binding FXIa inhibitor osocimab...With contact activation (ellagic acid or kaolin), the relative potency of thrombin inhibitionshifted: AB011 again showed the strongest inhibition on par with FXI-/- plasma, followed by gruticibart,and osocimab... FXI inhibitors produce anticoagulant effects across global coagulation assays that can bepartially or completely reversed by bypassing agents, particularly NovoSeven® and FEIBA®; however PT,TGA and viscoelastic testing also reveal the potential to generate a transient procoagulant/prothromboticstate if plasma concentrations of these commercially available agents are too high. The magnitude of theprocoagulant activity is dependent on the bypassing agent as well as the specific FXI inhibitor, suggestingthat reversal strategies should be tailored to the mechanism of the different FXI inhibitors (i.e. A2, A3, orcatalytic domain) to achieve optimal outcomes."

Hematological Disorders • Hemophilia • Rare Diseases

First randomized evaluation of safety, pharmacodynamics, and pharmacokinetics of BAY 1831865, an antibody targeting coagulation factor XI and factor XIa, in healthy men. (PubMed, J Thromb Haemost) - "BAY 1831865 i.v. or s.c. was well tolerated, with no evidence of bleeding in healthy volunteers. BAY 1831865 exhibited pronounced, sustained dose-dependent prolongation of aPPT and duration of FXI inhibition."

Journal • PK/PD data • Hematological Disorders • Immunology