Edoxaban (DU-176b, trade names Savaysa, Lixiana) is a selective factor Xa inhibitor reduces thrombin generation and thrombus formation and is an orally bioavailable anticoagulant drug. It was developed by Daiichi Sankyo to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF) and for the treatment of deep vein thrombosis and pulmonary embolism following 5-10 days of initial therapy with a parenteral anticoagulant.

Apixaban is an orally active inhibitor of coagulation factor Xa with anticoagulant activity. Apixaban directly inhibits factor Xa, thereby interfering with the conversion of prothrombin to thrombin and preventing formation of cross-linked fibrin clots. Apixaban has been available in Europe since May 2012. An FDA decision on apixaban which was expected on June 28, 2012 was initially delayed before final approval on December 28, 2012. On August 21, 2014, Pfizer announced that apixaban was now FDA approved for treatment and secondary prophylaxis of deep vein thrombosis (DVT) and pulmonary embolism (PE). It is being developed in a joint venture by Pfizer and Bristol-Myers Squibb. It has also been used to lower the risk of developing venous thrombosis post-orthopedic surgical procedures.

Rivaroxaban (trade name Xarelto) is an oral anticoagulant. It is the first available orally active direct factor Xa inhibitor. Upon oral administration, rivaroxaban selectively binds to both free factor Xa and factor Xa bound in the prothrombinase complex. This interferes with the conversion of prothrombin (factor II) to thrombin and eventually prevents the formation of cross-linked fibrin clots. Rivaroxaban does not affect existing thrombin levels. Activation of factor X to factor Xa (FXa) via the intrinsic and extrinsic pathways plays a central role in the cascade of blood coagulation. Xarelto is indicated to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, treatment and prophylaxis of deep vein thrombosis (DVT) which may lead to PE in patients undergoing knee or hip replacement surgery, pulmonary embolism (PE) and for the reduction in the risk of recurrence of deep vein thrombosis and of pulmonary embolism following initial 6 months treatment for DVT and/or PE.

Fondaparinux is a synthetic and specific inhibitor of activated Factor X (Xa). By selectively binding to antithrombin III (ATIII), fondaparinux sodium potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII. Neutralization of Factor Xa interrupts the blood coagulation cascade and thus inhibits thrombin formation and thrombus development. Fondaparinux is indicated for the prophylaxis of deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE): in patients undergoing hip fracture surgery, including extended prophylaxis; in patients undergoing hip replacement surgery; in patients undergoing knee replacement surgery; in patients undergoing abdominal surgery who are at risk for thromboembolic complications. The most serious adverse reactions reported with Fondaparinux are bleeding complications and thrombocytopenia. Agents that may enhance the risk of hemorrhage should be discontinued prior to initiation of therapy with Fondaparinux unless these agents are essential.

Eribaxaban (PD 348292) is an orally efficacious factor Xa inhibitor. It demonstrated antithrombotic efficacy in animal models. Pfizer was developing eribaxaban for the treatment of venous thrombosis.

Ciraparantag (PER-977, aripazine), developed by Perosphere Inc., is a small, synthetic, water-soluble, cationic molecule and can reverse the anticoagulation mediated by unfractionated heparin, low-molecular-weight heparin, factor Xa and factor IIa inhibitors, and fondaparinux. It has the potential to be a universal antidote, inhibiting nearly all anticoagulants except vitamin K antagonists and argatroban. In April 2015, ciraparantag received FDA fast-track designation as an investigational anticoagulant reversal agent. Phase I/II trials are currently underway to evaluate the safety and efficacy of PER977 in reversing anticoagulation of edoxaban, LMWH, and UFH.2.

Otamixaban is a synthetically derived parenteral fXa inhibitor currently in late stage clinical development at Sanofi-Aventis for the management of acute coronary syndrome. Otamixaban is a potent (Ki = 0.5 nM), selective, rapid acting, competitive and reversible fXa inhibitor that effectively inhibits both free and prothrombinase-bound fXa. Factor Xa (fXa) is a critical serine protease situated at the confluence of the intrinsic and extrinsic pathways of the blood coagulation cascade. FXa catalyzes the conversion of prothrombin to thrombin via the prothrombinase complex. Its singular role in thrombin generation, coupled with its potentiating effects on clot formation render it an attractive target for therapeutic intervention. In vivo experiments have demonstrated that Otamixaban is highly efficacious in rodent, canine and porcine models of thrombosis. In addition, recent clinical findings indicate that Otamixaban is efficacious, safe and well tolerated in humans and therefore has considerable potential for the treatment of acute coronary syndrome. Following the results of the Treatment of non-ST elevation Acute coronary syndrome with otamixaban, Sanofi has decided to discontinue the investigational programme with otamixaban, due to efficacy lower than expected. Otamixaban did not show superior benefit/risk to the combination of unfractionated heparin.

(1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) is a β-carboline indole alkaloid naturally occurring in plants, foods, insects, and endogenously in mammals and humans. It exerts antioxidant and antithrombotic properties. MTCA is thought to be a possible causative substance of eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan.

Betrixaban is an anticoagulant drug which acts as a direct factor Xa inhibitor. Betrixaban is now being developed by Portola Pharmaceuticals. Oral, once-daily Factor Xa inhibitor anticoagulant that directly inhibits the activity of Factor Xa, an important validated target in the blood coagulation pathway, to prevent life-threatening thrombosis. U.S. Food and Drug Administration granted Fast Track designation to betrixaban for extended-duration prevention of venous thromboembolism (VTE; blood clots) in acute medically ill patients (i.e., those who are hospitalized for serious medical conditions, such as heart failure, stroke, infection and pulmonary disease). Has the potential to become the first oral Factor Xa inhibitor anticoagulant approved for hospital-to-home prevention of VTE in acute medically ill patients.

Ximelagatran (Exanta or Exarta, H 376/95) is an anticoagulant that has been investigated extensively as a replacement for warfarin that would overcome the problematic dietary, drug interaction, and monitoring issues associated with warfarin therapy. In 2006, its manufacturer AstraZeneca announced that it would withdraw pending applications for marketing approval after reports of hepatotoxicity (liver damage) during trials, and discontinue its distribution in countries where the drug had been approved (Germany, Portugal, Sweden, Finland, Norway, Iceland, Austria, Denmark, France, Switzerland, Argentina and Brazil). Ximelagatran is a prodrug that is rapidly converted after oral administration to the active compound melagatran. Melagatran is able to inhibit thrombin activity directly and quickly. The melagatran molecule binds to the arginine side pocket of thrombin, inactivating the thrombin. Following oral administration of ximelagatran, oral bioavailability (measured as melagatran) is 18% to 25%. Peak melagatran levels after a ximelagatran dose of 48 mg twice daily are achieved within approximately 2 hours. Ximelagatran is rapidly and extensively converted to melagatran in the liver and other tissues. This conversion is achieved by ester hydrolysis and reduction via two intermediate metabolites, hydroxymelagatran, and ethylmelagatran. The predominant compound in plasma is the active drug, melagatran. The elimination half-life of melagatran after an oral dose of ximelagatran is 2.5 to 4.3 hours.