Pharmacological Profile of JNJ-64179375: A Novel, Long-Acting Exosite-1 Thrombin Inhibitor

Abstract

JNJ-64179375 (JNJ-9375) is a recombinant human IgG4 monoclonal antibody engineered to mimic an IgA antibody that was identified in a patient who exhibited markedly prolonged clotting times but without spontaneous bleeding episodes over several years of follow-up. The crystal structure of the JNJ-9375 antigen-binding fragment/thrombin complex showed an almost identical binding mode to that of the patient IgA. In the current study, we characterized the in vitro and in vivo properties of JNJ-9375. Surface plasmon resonance studies demonstrated that JNJ-9375 binds to a-thrombin with high affinity and specificity (K D : 0.8 nM for human thrombin). JNJ-9375 produced concentration-dependent prolongation of in vitro clotting assays in human plasma, including thrombin time (TT), ecarin clotting time, prothrombin time, and activated partial thromboplastin time, with EC 2X values of 4.4, 12.4, 172.6, and 202.7 mg/ml, respectively. JNJ-9375 inhibited thrombin-induced platelet aggregation in human plasma with an IC 50 value of 52.6 nM (7.8 mg/ml) and produced concentration-dependent prolongation of reaction time tested by thromboelastography. JNJ-9375 pretreatment resulted in dose-dependent reduction in thrombus formation in the rat arteriovenous (AV) shunt model of thrombosis. Robust efficacy was observed at 0.3 mg/kg accompanied by 1.5Â of TT. Bleeding was increased at 3 mg/kg in a rat tail transection bleeding model demonstrating a therapeutic index of 10Â compared with 1Â for apixaban in the same models. Our data suggest that thrombin exosite I inhibition is efficacious against thrombosis in a pretreatment prevention animal model. SIGNIFICANCE STATEMENT JNJ-9375 is a novel, fully human monoclonal antibody that binds to the exosite I region of thrombin with high affinity and specificity. JNJ-9375 concentration dependently prolonged clotting times and inhibited thrombin-induced platelet aggregation in in vitro assays based on its mechanism of action. In an in vivo rat AV shunt model, JNJ-9375 prevented thrombus formation in a dose-dependent fashion while demonstrating reduced bleeding risk. The present study demonstrated the antithrombotic effects of inhibiting the exosite I region of thrombin when given in a prevention mode in preclinical animal models.

Translational PK/PD and model‐informed development of JNJ‐67842125, a Fab reversal agent for JNJ‐64179375, a long‐acting thrombin inhibitor

“…Based on SPR experiments, JNJ‐9375 binds to α‐thrombin with similar K D values of 1.0 and 0.8 nM in cynomolgus monkeys and humans (Huang Devine et al, 2019). Our in vitro (SPR) and in vivo (PK/PD studies indicate that JNJ‐2125 bound JNJ‐9375 with an affinity ~100‐fold higher than the affinity of JNJ‐9375 for thrombin.…”

“…Although the newer generation direct oral anticoagulants offer substantial advantages over warfarin, the risk of bleeding with these drugs—as with all existing anticoagulants—remains an ongoing safety concern (Eikelboom & Merli, 2016). JNJ‐64179375 (JNJ‐9375 hereafter) is a first‐in‐class, recombinant, fully human IgG4 monoclonal antibody (mAb) that binds with high affinity and specificity to exosite‐1 on thrombin and acts as an anticoagulant (Huang Devine et al, 2019). As a result, JNJ‐9375 inhibits thrombosis in vitro (Bunce et al, 2018), in preclinical models (Chintala, Li, Huang Devine, & Bunce, 2017; Huang Devine et al, 2019), and in ex vivo human translational models of thrombosis (Wilson et al, 2019).…”

“…JNJ‐64179375 (JNJ‐9375 hereafter) is a first‐in‐class, recombinant, fully human IgG4 monoclonal antibody (mAb) that binds with high affinity and specificity to exosite‐1 on thrombin and acts as an anticoagulant (Huang Devine et al, 2019). As a result, JNJ‐9375 inhibits thrombosis in vitro (Bunce et al, 2018), in preclinical models (Chintala, Li, Huang Devine, & Bunce, 2017; Huang Devine et al, 2019), and in ex vivo human translational models of thrombosis (Wilson et al, 2019). In a preclinical rat arteriovenous shunt model of thrombosis, JNJ‐9375 was associated with substantially less bleeding when compared to apixaban at doses of equivalent antithrombotic efficacy (Chintala, Li, Huang Devine, & Bunce, 2017; Chintala, Li, Huang‐Devine, et al, 2017), demonstrating a potential wider therapeutic index.…”

An anticoagulant that does not cause bleeding – an abrupt stop on the road to the Holy Grail

“…compared to the paraprotein. 10 JNJ-9375 inhibited thrombin-induced platelet aggregation but not the aggregation induced by other agonists. There was a small increase in lag time in thrombin generation analyses, but hardly any effects on peak thrombin or the endogenous thrombin potential.…”

“…In a rat arteriovenous shunt model of thrombosis, pretreatment with JNJ-9375 dose-dependently reduced thrombus formation with a better safety profile than its comparator apixaban. 10 The logical next step was therefore to test the anti-…”