New guidelines from the British Society for Haematology (BSH) offer a less restrictive approach to the use of DOACS in antiphospholipid syndrome (APS) compared to recent regulatory agency bans.
In 2019 medicine regulators including the TGA recommended that DOACS should not be used in patients with APS, after extrapolating results from the TRAPS1 study that showed an increase in the risk of recurrent thrombotic events with rivaroxaban compared to warfarin in patients with APS who were ‘triple positive’ for all three antiphospholipid antibodies (lupus anticoagulant, anticardiolipin and anti-β2-glycoprotein I antibodies).
However in a new addendum to its guidelines on the management of APS, the British Society for Haematology Haemostasis and Thrombosis Taskforce says that the evidence from studies such as TRAPS1 is not sufficient to make strong recommendations in patients with non‐triple positive APS.
The Taskforce notes that most of the recurrent thrombotic events reported in the rivaroxaban arm of the TRAPS1 trial occurred in patients who received it for arterial thrombosis, which is an unlicensed indication.
They also note that no increase in recurrent thrombosis was seen with rivaroxaban compared to warfarin in a previous study, the RAPS (Rivaroxaban in Antiphospholipid Syndrome) trial in which the majority of patients were not triple positive.
The BSH has therefore added recommendations regarding the use of DOACs in patients with thrombotic APS:
For patients with non‐triple positive APS and venous thrombosis, it states that there is insufficient evidence to make strong recommendations in this group of patients.
“We suggest against the initiation of DOACs for treatment or secondary prophylaxis in patients with venous thrombosis and known non‐triple positive APS (Grade 2C).
“Patients who are already on a DOAC may continue or switch to a vitamin K antagonist (VKA) after discussion with the patient taking into account their clinical history, treatment adherence and previous experience. For those patients who do not wish to switch, we recommend continuation of the DOAC over no anticoagulation (Grade 2C).”
For patients with triple positive APS and venous thrombosis, the Society recommend against the initiation of DOACs for treatment or secondary prophylaxis.
“For patients with triple positive APS who are currently on a DOAC, we recommend switching from the DOAC to a VKA after discussion with patients regarding the available evidence. For those patients who do not wish to switch, we recommend continuation of the DOAC over no anticoagulation (Grade 1B).
The BSH also does not recommends use of DOACs in patients for anticoagulation for treatment and secondary prophylaxis of arterial thrombosis in patients with APS.