Background
Milvexian (BMS‐986177/JNJ‐70033093) is an orally bioavailable factor XIa (FXIa) inhibitor currently in phase 2 clinical trials.
Objectives
To evaluate in vitro properties and in vivo ...characteristics of milvexian.
Methods
In vitro properties of milvexian were evaluated with coagulation and enzyme assays, and in vivo profiles were characterized with rabbit models of electrolytic‐induced carotid arterial thrombosis and cuticle bleeding time (BT).
Results
Milvexian is an active‐site, reversible inhibitor of human and rabbit FXIa (Ki 0.11 and 0.38 nM, respectively). Milvexian increased activated partial thromboplastin time (APTT) without changing prothrombin time and potently prolonged plasma APTT in humans and rabbits. Milvexian did not alter platelet aggregation to ADP, arachidonic acid, or collagen. Milvexian was evaluated for in vivo prevention and treatment of thrombosis. For prevention, milvexian 0.063 + 0.04, 0.25 + 0.17, and 1 + 0.67 mg/kg+mg/kg/h preserved 32 ± 6*, 54 ± 10*, and 76 ± 5%* of carotid blood flow (CBF) and reduced thrombus weight by 15 ± 10*, 45 ± 2*, and 70 ± 4%*, respectively (*p < .05; n = 6/dose). For treatment, thrombosis was initiated for 15 min and CBF decreased to 40% of control. Seventy‐five minutes after milvexian administration, CBF averaged 1 ± 0.3, 39 ± 10, and 66 ± 2%* in groups treated with vehicle and milvexian 0.25 + 0.17 and 1 + 0.67 mg/kg+mg/kg/h, respectively (*p < .05 vs. vehicle; n = 6/group). The combination of milvexian 1 + 0.67 mg/kg+mg/kg/h and aspirin 4 mg/kg/h intravenous did not increase BT versus aspirin monotherapy.
Conclusions
Milvexian is an effective antithrombotic agent with limited impact on hemostasis, even when combined with aspirin in rabbits. This study supports inhibition of FXIa with milvexian as a promising antithrombotic therapy with a wide therapeutic window.
Factor XIa (FXIa) is a blood coagulation enzyme that is involved in the amplification of thrombin generation. Mounting evidence suggests that direct inhibition of FXIa can block pathologic thrombus ...formation while preserving normal hemostasis. Preclinical studies using a variety of approaches to reduce FXIa activity, including direct inhibitors of FXIa, have demonstrated good antithrombotic efficacy without increasing bleeding. On the basis of this potential, we targeted our efforts at identifying potent inhibitors of FXIa with a focus on discovering an acute antithrombotic agent for use in a hospital setting. Herein we describe the discovery of a potent FXIa clinical candidate, 55 (FXIa K i = 0.7 nM), with excellent preclinical efficacy in thrombosis models and aqueous solubility suitable for intravenous administration. BMS-962212 is a reversible, direct, and highly selective small molecule inhibitor of FXIa.
Efforts to identify a suitable follow-on compound to razaxaban (compound 4) focused on modification of the carboxamido linker to eliminate potential in vivo hydrolysis to a primary aniline. ...Cyclization of the carboxamido linker to the novel bicyclic tetrahydropyrazolopyridinone scaffold retained the potent fXa binding activity. Exceptional potency of the series prompted an investigation of the neutral P1 moieties that resulted in the identification of the p-methoxyphenyl P1, which retained factor Xa binding affinity and good oral bioavailability. Further optimization of the C-3 pyrazole position and replacement of the terminal P4 ring with a neutral heterocycle culminated in the discovery of 1-(4-methoxyphenyl)-7-oxo-6-(4-(2-oxopiperidin-1-yl)phenyl)-4,5,6,7-tetrahydro-1H-pyrazolo3,4-cpyridine-3-carboxamide (apixaban, compound 40). Compound 40 exhibits a high degree of fXa potency, selectivity, and efficacy and has an improved pharmacokinetic profile relative to 4.
Factor XIa (FXIa) is an enzyme in the coagulation cascade thought to amplify thrombin generation but has a limited role in hemostasis. From preclinical models and human genetics, an inhibitor of FXIa ...has the potential to be an antithrombotic agent with superior efficacy and safety. Reversible and irreversible inhibitors of FXIa have demonstrated excellent antithrombotic efficacy without increased bleeding time in animal models ( Weitz, J. I. , Chan, N. C. Arterioscler. Thromb. Vasc. Biol. 2019, 39 (1), 7−12 ). Herein, we report the discovery of a novel series of macrocyclic FXIa inhibitors containing a pyrazole P2′ moiety. Optimization of the series for (pharmacokinetic) PK properties, free fraction, and solubility resulted in the identification of milvexian (BMS-986177/JNJ-70033093, 17, FXIa K i = 0.11 nM) as a clinical candidate for the prevention and treatment of thromboembolic disorders, suitable for oral administration.
The dose-limiting issue with available anticoagulant therapies is bleeding. Is there an approach that could provide antithrombotic protection with reduced bleeding? One hypothesis is that targeting ...proteases upstream from the common pathway provides a reduction in thrombin sufficient to impede occlusive thrombosis yet allows enough thrombin generation to support hemostasis. The impairment of intrinsic coagulation by selective inhibition of factor XI (FXI) leaves the extrinsic and common pathways of coagulation intact, making FXI a drug target. This concept is supported by the observation that human deficiency in FXI results in a mild bleeding disorder compared with other coagulation factor deficiencies, and that elevated levels of FXI are a risk factor for thromboembolic disease. Moreover, FXI knockout mice have reduced thrombosis with little effect on hemostasis. The results from genetic models have been supported by studies using neutralizing antibodies, peptide inhibitors, and small-molecule inhibitors. These agents impede thrombosis without affecting bleeding time in a variety of experimental animals, including primates. Together, these data strongly support FXIa inhibition as a viable method to increase the ratio of benefit to risk in an antithrombotic drug.
Factor XIa Inhibitors as New Anticoagulants Quan, Mimi L; Pinto, Donald J. P; Smallheer, Joanne M ...
Journal of medicinal chemistry,
09/2018, Letnik:
61, Številka:
17
Journal Article
Recenzirano
With the introduction of thrombin and factor Xa inhibitors to the oral anticoagulant market, significant improvements in both efficacy and safety have been achieved. Early clinical and preclinical ...data suggest that inhibitors of factor XIa can provide a still safer alternative, with expanded efficacy for arterial indications. This Perspective provides an overview of target rationale and details of the discovery and development of inhibitors of factor XIa as next generation antithrombotic agents.
Aims
The aims of the present study were to assess the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of BMS‐962212, a first‐in‐class factor XIa inhibitor, in Japanese and non‐Japanese ...healthy subjects.
Methods
This was a randomized, placebo‐controlled, double‐blind, sequential, ascending‐dose study of 2‐h (part A) and 5‐day (part B) intravenous (IV) infusions of BMS‐962212. Part A used four doses (1.5, 4, 10 and 25 mg h−1) of BMS‐962212 or placebo in a 6:2 ratio per dose. Part B used four doses (1, 3, 9 and 20 mg h−1) enrolling Japanese (n = 4 active, n = 1 placebo) and non‐Japanese (n = 4 active, n = 1 placebo) subjects per dose. The PK, PD, safety and tolerability were assessed throughout the study.
Results
BMS‐962212 was well tolerated; there were no signs of bleeding, and adverse events were mild. In parts A and B, BMS‐962212 demonstrated dose proportionality. The mean half‐life in parts A and B ranged from 2.04 to 4.94 h and 6.22 to 8.65 h, respectively. Exposure‐dependent changes were observed in the PD parameters, activated partial thromboplastin time (aPTT) and factor XI clotting activity (FXI:C). The maximum mean aPTT and FXI:C change from baseline at 20 mg h−1 in part B was 92% and 90%, respectively. No difference was observed in weight‐corrected steady‐state concentrations, aPTT or FXI:C between Japanese and non‐Japanese subjects (P > 0.05).
Conclusion
BMS‐962212 has tolerability, PK and PD properties suitable for investigational use as an acute antithrombotic agent in Japanese or non‐Japanese subjects.
Modification of a series of pyrazole factor Xa inhibitors to incorporate an aminobenzisoxazole as the P1 ligand resulted in compounds with improved selectivity for factor Xa relative to trypsin and ...plasma kallikrein. Further optimization of the P4 moiety led to compounds with enhanced permeability and reduced protein binding. The SAR and pharmacokinetic profile of this series of compounds is described herein. These efforts culminated in 1-(3‘-aminobenzisoxazol-5‘-yl)-3-trifluoromethyl-N-2-fluoro-4-(2‘-dimethylaminomethyl)imidazol-1-ylphenyl-1H-pyrazole-5-carboxyamide (11d), a potent, selective, and orally bioavailable inhibitor of factor Xa. On the basis of its excellent in vitro potency and selectivity profile, high free fraction in human plasma, good oral bioavailability, and in vivo efficacy in antithrombotic models, the HCl salt of this compound was selected for clinical development as razaxaban (DPC 906, BMS-561389).
Factor XIa (FXIa) inhibitors are promising novel anticoagulants, which show excellent efficacy in preclinical thrombosis models with minimal effects on hemostasis. The discovery of potent and ...selective FXIa inhibitors which are also orally bioavailable has been a challenge. Here, we describe optimization of the imidazole-based macrocyclic series and our initial progress toward meeting this challenge. A two-pronged strategy, which focused on replacement of the imidazole scaffold and the design of new P1 groups, led to the discovery of potent, orally bioavailable pyridine-based macrocyclic FXIa inhibitors. Moreover, pyridine-based macrocycle 19, possessing the phenylimidazole carboxamide P1, exhibited excellent selectivity against relevant blood coagulation enzymes and displayed antithrombotic efficacy in a rabbit thrombosis model.
PDF
