Rivaroxaban in Antiphospholipid Syndrome (RAPS)

• Research type

  Research Study

• Full title

  A prospective randomised controlled phase II/III clinical trial of rivaroxaban versus warfarin in patients with thrombotic antiphospholipid syndrome, with or without SLE.

• IRAS ID

  97943

• Contact name

  Hannah Cohen

• Eudract number

  2012-002345-38

• ISRCTN Number

  not issued

• Research summary

  Antiphospholipid syndrome (APS) is an autoimmune disease that is caused by antibodies against normal blood proteins that bind to cell-membrane phospholipids that can provoke thrombosis. Patients with thrombotic APS experience venous and/or arterial thrombosis in association with persistent antiphospholipid antibodies. These thrombotic events are potentially fatal and patients require long-term anticoagulation therapy, with warfarin the mainstay. APS can also occur in patients with other autoimmune diseases, such as systemic lupus erythematosus (SLE). Treatment with warfarin, although effective, is problematic as it can interact with numerous drugs and dietary constituents. Its action can also be affected by alcohol, smoking, intercurrent illness and exercise. Patients therefore require frequent monitoring, which is inconvenient for the patient and costly for the NHS. Rivaroxaban is a new, recently introduced fixed-dose oral anticoagulant with predictable anticoagulant effect, few reported drug interactions and no interactions with food or alcohol, and does not require routine anticoagulant monitoring. 156 patients with venous thromboembolism on warfarin for at least 6 months at a target INR (International Normalised Ratio; the test used to monitor the anticoagulant effects of warfarin)of 2-5, will be randomised to either continue with warfarin, or to switch to a daily 20mg dose of rivaroxaban for 6 months. After the therapeutic phase of the trial, patients will be offered what is considered appropriate anticoagulation. The primary aim of the trial is to assess the non-inferiority of the anticoagulant effects of rivaroxaban in comparison to warfarin. This will be achieved by comparing thrombin generation 42 days after randomisation in the two groups, assessed by the thrombin generation test (TGT), with the endogenous thrombin potential (ETP) a key parameter. The TGT is a global measure of anticoagulation, which can assess the anticoagulant effects of both rivaroxaban and warfarin (drugs with very different modes of action on the coagulation mechanism).

• REC name

  South Central - Oxford A Research Ethics Committee

• REC reference

  12/SC/0566

• Date of REC Opinion

  30 Oct 2012

• REC opinion

  Further Information Favourable Opinion