Evaluation of the Use of Apixaban in Prevnetion of Thromboembolic Disease in Patients With Myeloma Trated With iMiDs

Inclusion Criteria: * Patients (men/women) aged more than 18 years * All consecutive patients, with myeloma, in first-line treatment or in relapse, who are treated - With IMiDs (MPT, Melphalan -Prednisone -Thalidomide ; Lenalidomide - Dexamethasone). AND \- who require prevention of venous thromboembolic events with Aspirin or Low molecular Weight Heparin (LMWH) for a minimum duration of 6 months At least, 2/3 of patients will be treated with Lenalidomide-Dexamethasone. * Written informed consent * Patients affiliated to the French social security system or equivalent Exclusion Criteria: * Patient who needs curative anticoagulant treatment (heparin, LMWH, vitamin K antagonists, Dabigatran, Rivaroxaban, Apixaban) for an associated disorder (mechanical valve, atrial fibrillation or venous thromboembolic disease in the previous 6 months). * Patient who needs preventive treatment with an anticoagulant in a post-operative context * Patient who needs anti-platelet treatment (Aspirin, Clopidogrel, Prasugrel, Ticagrelor or dual anti-platelet therapy ) * Patient with active bleeding or at a high risk of bleeding (ulcer disease, intracranial bleeding in the previous 6 months, uncontrolled hypertension) * Patient having undergone a surgical intervention within the past 30 days likely to expose them to an haemorrhagic risk * Active hepatic disease (hepatitis, cirrhosis) * Severe renal insufficiency (creatinine clearance using the Cockcroft equation \< 30 ml/mn) * Known allergic rea…