Lenalidomide, Rituximab, Gemcitabine, Oxaliplatin and Dexamethasone in Relapse and Refractory DLBCL

Inclusion Criteria: * Age 18-65 years old; * ECOG PS 0- 2; * Histologically confirmed diffuse large B cell lymphoma（With exception of Primary mediastinal large B cell lymphoma、Primary central nervous system lymphoma、HIV-related lymphoma),relapse or refractory,defined as: * relapse after standard first-line immunochemotherapy( R-CHOP or R-CHOP like) * SD as best response after 4 cycles or PD after 2 cycles of first-line immunochemotherapy; * a measurable or evaluable disease at the time of enrollment(diameter ≥ 1.5cm）； * Eligible for subsequent autologous stem cell transplantation； * Female subjects in childbearing age, their serum or urine pregnancy test must be negative. All patients must agree to take effective contraceptive measures during the trial measures * Expected survival ≥ 12 weeks； * Understand and voluntarily sign an informed consent form, able to adhere to the study visit schedule and other protocol requirements Exclusion Criteria: * Women who are pregnant or lactating. Patients have breeding intent in 12 months or cannot take effective contraceptive measures during the trial measures； * Uncontrollable active infection within four week. Prophylactic antibiotic, antiviral and antifungal treatment is permissible. Active hepatitis B or hepatitis C virus infection, as well as acquired, congenital immune deficiency diseases, including but not limited to HIV-infected persons； * Used of systemic anti-tumor treatment within four weeks； * CNS or meningeal involvement; * Poor hepatic and/or renal function, defined as total bilirubin, ALT, AST, Cr more than two fold of upper normal level,Ccr\< 50 mL/min unless these abnormalities were related to the lymphoma; * Poor bone-marrow reserve, defined as neutrophil count less than 1.5×10⁹/L or platelet count less than 75×10⁹/L, unless caused by bone marrow infiltration; * New York Heart Association class III or IV cardiac failure; or Ejection fraction less than 50%;or history of following disease in past 6 months: acute coronary syndrome、acute heart failure、severe ventricular arrhythmia； * Known sensitivity or allergy to investigational Product; * Major surgery within three weeks; * Presence of Grade III nervous toxicity within past two weeks; * Active and severe infectious diseases; * History of DVT or PE within past 12 months； * Any potential drug abuse, medical, psychological or social conditions which may disturb this investigation and assessment; * In any conditions which investigator considered ineligible for this study.