The Comprehensive Clinical Trials Unit at UCL


RAPS Rivaroxaban in Anti-Phospholipid Syndrome

1 November 2018


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

Antiphospholipid syndrome (APS) is an autoimmune disease that is caused by antibodies against normal blood proteins that bind to cell-membrane phospholipids and can provoke thrombosis. These thrombotic events are potentially fatal and patients require long-term anticoagulation therapy, with warfarin being the mainstay. Rivaroxaban is a recently introduced fixed-dose oral anticoagulant which, unlike warfarin, does not require routine anticoagulant monitoring. The primary aim of the RAPS trial is to assess whether the anticoagulant effects of rivaroxaban are not inferior to those of warfarin, in patients who have thrombotic APS and are on warfarin. This will be achieved by comparing the percentage change in endogenous thrombin potential (ETP), assessed by the thrombin generation test (TGT), from randomisation to day 42. The ETP is a global measure of the anticoagulant effects. The TGTs will be performed in the UCL Haemostasis Research Unit.