Rivaroxaban Is an Effective and Well Tolerated Anti Thrombotic Agent in Patients on Lenalidomide Therapy and in Multiple Myeloma

Patients with multiple myeloma are at high risk of thrombosis. Treatment with Lenalidomide increases this risk with venous thrombo embolic events (very common, ≥ 1/10) and myocardial infarction and stroke being common (≥ 1/100 to < 1/10) adverse events. Lenalidomide treatment often continues until disease progression or intolerance. Anticoagulation with oral vitamin K antagonists such as warfarin is often challenging in this patient group due to erratic INRs, frequent need for blood tests and multiple interactions with myeloma therapy. Prolonged treatment with low molecular weight heparin results in injection site tenderness besides cutaneous bruising.

There is no published data exploring role of newer anticoagulants as anti thrombotic agents in multiple myeloma on Lenalidomide therapy.

Rivaroxaban, an oral anti Xa inhibitor, is a newer anticoagulant which does not require INR monitoring and is licensed for thromboprophylaxis in atrial fibrillation and treatment of deep vein thrombosis / pulmonary embolism.

This is a retrospective non randomised observational study which looked at cohort of myeloma patients at high risk of thrombosis and included patients on Lenalidomide. Follow up duration varied from 3 to 12 months.

The cohort consisted of 7 patients, age range 53 to 86 years; 3 males, 4 females; dosage range 10 mg to 20 mg (guided by indication and adjusted for renal function). Indication for anti thrombotic treatment included: Deep Vein Thrombosis (n = 1), recurrent DVT (3), recurrent Pulmonary Embolism (2) and Atrial fibrillation (2). One patient had both recurrent DVT & PE. Of 7 patients, 5 were on treatment with Lenalidomide. Rivaroxaban was intended to continue long term whilst thromboembolic risks persisted. Rivaroxaban was well tolerated with only a single episode of minor bleed (oral mucosal) which resolved spontaneously. No new thromboembolic events were reported on treatment. All patients were able to continue on anti myeloma therapy (see table 1).

These data indicate that Rivaroxaban is an effective and well tolerated anti thrombotic agent in patients on Lenalidomide therapy and in multiple myeloma thus providing an option to prolonged treatment with subcutaneous low molecular weight heparin or oral vitamin K antagonists.