The Efficacy and Safety of Pomalidomide and Bendamustine With Dexamethasone in Relapsed or Refractory Multiple Myeloma

Inclusion Criteria: * Age of 18-75, no gender limitations. * Ability of contraception during the experiment, no matter if they have suffered from infertility. * Relapsed or refractory to prior lenalidomide or/and bortezomib(either in combination or sequential)therapy (i.e. history of progression on therapy or within 60 days after completion) * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-2, life expectancy of more than 6 months. * Measurable disease: Serum M protein \> 10 g/L or Urine M protein ≥200 mg/24 hr or Elevated Free Light Chain per International Myeloma Working Group (IMWG) criteria, and abnormal ratio. * Absolute neutrophil count (ANC) \>1.0 x 109/L or \>1.0 x 109/L due to granulocyte/macrophage colony stimulating factor (GCSF and GMCSF), or if \>50% marrow involvement, there is no limitations * Platelet count \>50.0 x 109/L or if \>50% marrow involvement, there is no limitations. * Total bilirubin ≤ 2.0mg/dL, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 3 times the upper limit of normal. * Serum creatinine ≤2.0 mg/dL or creatinine clearance ≥60ml/min. * Agree to take anticoagulant drugs, included but not limited to aspirin. * Agree to sign the informed consent form. Exclusion Criteria: * Patients with known sensitivity to pomalidomide or bendamustine or dexamethasone and their accessories. * Patients with primary systemic amyloidosis or monoclonal gammopathy of undetermined significance or smoldering multiple …