The Rivaroxaban in APS (RAPS) trial is now recruting new patients to the trial. Our charity has agreed to help with this important trial as it could finally provide a safe alternative treatment to warfarin.
Below is the recruitment paper from Professor Hannah Cohen of University College Hospital in London but, to put simply, they have a very strict criteria where the patient:
- has a positive diagnosis of APS
- is based in the UK
- has only had a DVT and/or PE, but not a stroke or TIA related to APS
- has a target INR range of between 2.0–3.0
- has been taking warfarin for at least three months
If you meet the criteria and can travel to one of the London centres (either UCL or the Haematology Department at St Thomas') then please do get in touch. There will be six visits in seven months and your travel expenses will be paid for.
Thanks in advance to anyone who is able to participate,
Kate - firstname.lastname@example.org
RAPS (Rivaroxaban in AntiPhospholipid Syndrome)
A prospective randomised controlled phase II/III clinical trial of rivaroxaban versus warfarin in patients with thrombotic antiphospholipid syndrome, with or without SLE
Background and study aims
In patients with antiphospholipid syndrome (APS), with or without ‘lupus’, long-term anticoagulation with warfarin is the established treatment following deep vein thrombosis (DVT) and/or pulmonary embolism (PE) to prevent further thrombosis, which can be life-threatening.
Rivaroxaban is a recently introduced oral anticoagulant (blood thinner), which is given as fixed-dose tablets once daily. Unlike warfarin, rivaroxaban does not require routine INR monitoring blood tests because it has a predictable anticoagulant effect, similar to heparin injections. Also, unlike warfarin, rivaroxaban does not interact with food or alcohol and has few drug interactions. It is unlikely that antiphospholipid antibodies will interfere with rivaroxaban's effects on blood clotting (as is the case with warfarin) as, unlike warfarin, it has a very targeted effect on blood.
We are comparing the anticoagulant (blood thinning) effect of rivaroxaban with that of warfarin in patients with thrombotic APS, with or without ‘lupus’. We are doing this by assessment of a specialised and excellent measure of anticoagulation called the 'thrombin generation test' (TGT). We are also assessing rates of bleeding and further thrombosis, and comparing serious adverse events and quality of life in patients on rivaroxaban with those on warfarin. If we can demonstrate that the anticoagulant effect of rivaroxaban is not inferior to that of warfarin, and that there is no increase in the rate of serious adverse effects (very unlikely – see below), we believe that this would provide good evidence to change practice for our patients, and make rivaroxaban the standard of care for patients with thrombotic APS, with or without ‘lupus’.
Who can participate?
Patients with thrombotic APS, with or without lupus, who have had a DVT and/or PE (but not a TIA (transient ischaemic attack) or stroke related to APS), and have been on warfarin at a target INR of 2.5 (range 2.0–3.0) for at least three months are eligible to take part in the study.
Some patients being run at a target INR of 2.0-3.0 and who have had more than one DVT and/or PE may also be eligible if the event occurred whilst off anticoagulation or when there was inadequate anticoagulation.
The trial results will not be applicable to patients who require a higher target INR range than 2.0-3.0. This is because there are no studies to compare warfarin versus rivaroxaban in patients being run at a higher target INR and therefore, future studies are needed to see whether rivaroxaban would be effective for such patients.
What does the study involve?
Patients are randomly allocated to either remain on warfarin or to switch to rivaroxaban. The trial involves six visits over a seven month period. Trial visits will enable face-to-face contact with healthcare professionals to discuss any concerns and patients will be able to contact the Research Nurse to discuss any problems between visits. Two extra blood samples (each about four teaspoonfuls) will be taken prior to random allocation and six weeks later, in addition to routine blood tests. The trial treatment will last for six months and following this, patients will be offered appropriate anticoagulation.
What are the possible benefits and risks of participating?
Rivaroxaban is licensed in the UK and approved by NICE for the prevention of DVT/PE in patients undergoing hip and knee replacements and also for the treatment of DVT and prevention of recurrent DVT and PE following an acute DVT; and the prevention of stroke in patients with atrial fibrillation (an abnormal heart rhythm associated with an increased risk of stroke). Studies on tens of thousands of patients with DVT/PE or other conditions have shown that rivaroxaban is effective with a similar safety profile to warfarin. Indeed, to date in studies on a total of over 65,000 patients no major safety issues have emerged. It is likely that some patients with APS were included in the studies on DVT/PE, but there is no separate information available on this group.
Where is the study run from?
The study is taking place at University College London Hospitals NHS Foundation Trust and Guys and St Thomas’ NHS Foundation Trust (UK).
Arthritis Research UK and a drug company (http://www.controlled-trials.com/ISRCTN68222801)
If you are interested in participating in this trial, please contact either:
Dr Hannah Cohen
Department of Haematology UCL Division of Medicine
1st Floor Central, 250 Euston Road
London NW1 2PG
Professor Beverley Hunt
Department of Haematology
Guy’s and St Thomas’ NHS Foundation Trust
London SE1 7EG