Development and clinical applications of novel oral anticoagulants. Part II. Drugs under clinical investigation.

Following the clinical approval of novel oral anticoagulants as alternatives to the vitamin K antagonists, many additional novel oral anticoagulant drugs are currently in early and advanced stages of clinical development. The majority of the drugs in development belong to the class of direct factor Xa inhibitors (the -xabans). These include betrixaban, letaxaban, darexaban, eribaxaban, and LY517717. Another representative of the class of orally available direct thrombin inhibitors (the -gatrans) is known as AZD0837. Furthermore other coagulation factors with central roles within the coagulation cascade are currently investigated as potential targets for the development of novel oral anticoagulant drugs. Among those, the first direct oral factor IXa inhibitor TTP889 has entered the clinical phase of development. A short summary of novel oral anticoagulant currently in earlier stages of clinical development is provided.