Letaxaban

The direct oral anticoagulants (DOAC) have similar half-lives, but the dosing regimen varies between once daily (QD) or twice daily (BID). For some prescribers, the QD regimen improves compliance. Others prefer BID regimens to promote better stability of plasma concentrations, particularly in the event of missed doses. Limited level of evidence provides guidance about the best treatment strategy. The purpose of this study was to compare the treatment effect of QD vs. BID administration of DOACs in major orthopedic surgery (MOS), non-valvular atrial fibrillation (NVAF), venous thromboembolism (VTE), and acute coronary syndrome (ACS).

We conducted a systematic review up to April 2020. We included phase II clinical trials comparing DOAC QD vs BID with same daily dose. We extracted data for the occurrence of major thrombosis (proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke) and major hemorrhage (ISTH criteria and recommendations of the European Medicines Agency for surgical patients). Relative risks (RR) were combined using a fixed and random effects weighted meta-analysis.

Twelve randomized, controlled, phase II trials were included (10,716 patients), representing 24 dosing regimen comparisons of apixaban, darexaban, edoxaban, rivaroxaban, letaxaban, and dabigatran. There was no difference for major thrombotic event (RR_BID/QD = 1.06, 95%IC 0.86-1.30) nor for major bleeding (RR_BID/QD = 1.02, 95%IC 0.84-1.23) between the BID vs QD regimens, without heterogeneity (I² = 0%).

Our study does not support a global difference in term of efficacy and safety of the BID and QD regimens of DOAC in MOS, NVAF, VTE and ACS.

Anticoagulant drugs comprise a specific subcategory of antithrombotic agents that act to inhibit blood coagulation at various stages, reducing clot development and ultimately lowering the risk of developing new-onset or recurrent thrombosis. Although the long history of anticoagulant drugs has been characteristically shaped by coumarin and heparin derivatives, a new generation of direct oral anticoagulants (DOACs), which specifically inhibit thrombin or activated factor X, combine many advantages of their progenitor drugs, and hence are prepotently revolutionizing the landscape of antithrombotic therapy. Several drugs (apixaban [BMS-562247], dabigatran [BIBR953], edoxaban [DU-1766], rivaroxaban [BAY 59–7939]) have already received widespread approval by national or supranational medicinal agencies. This narrative article provides a state-of-the-art for these and for several other DOACs at different stages of clinical evaluation (betrixaban, darexaban, eribaxaban, letaxaban, nokxaban), and certain others whose development has been discontinued (AZD-0837, fidexaban, LY517717, odiparcil, otamixaban, TTP889, and ximelagatran). What clearly emerges from our analysis is that DOACs sharing very similar mechanisms of action are still characterized by different efficacy and safety profiles. This not only depends on biochemical, biological, and pharmacokinetic characteristics, but also on lack of standardization between different clinical trials in terms of targeted disease, patient recruitment, sample size, duration and endpoints, as well as lack of harmonization around procedures used for drug licensing. These factors contribute to challenging the minds of physicians, who may find difficulty navigating their way through multiple indications, different pharmacological profiles, various side effects, and specific drug-to-drug interactions. Such considerations also burden laboratory professionals, who may face organizational and economic challenges in developing and/or implementing multiple assays to assess the pharmacodynamics (effect on coagulation) or pharmacokinetics (drug levels) of DOACs.