The prognosis of DLBCL with MYC rearrangement is dismal. Previous study showed that lenalidomide in combination with R-CHOP showed promising therapeutic activity and that R-DA EPOCH was superior compared to R-CHOP regimen in this cohort of patients. The investigators therefore design this phase I/II study to investigate the safety and efficacy of lenalidomide in combination with R-DA EPOCH in patients with untreated MYC-rearranged DLBCL.

Inclusion Criteria:

1. Histologically confirmed DLBCL with MYC rearrangement according to WHO 2016 criteria, excluding PMBCL, PCNSL, HIV-associated lymphoma.
2. ECOG PS 0-2
3. Age 18-60 years old
4. Expected survival ≥ 12 weeks
5. A measurable or evaluable disease at the time of enrolment (diameter ≥1.5cm)
6. Understand and voluntarily sign an informed consent form, able to adhere to the study visit schedule and other protocol requirements.

Exclusion Criteria:

1. Women who are pregnant or lactating. Patients have breeding intent in 12 months or cannot take effective contraceptive measures during the trial measures
2. Active hepatitis B or hepatitis C virus infection, as well as acquired, congenital immune deficiency diseases, including but not limited to HIV infected persons
3. Previous exposure to any anti-tumor therapy
4. 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
5. History of DVT or PE within past 12 months
6. 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
7. 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
8. CNS or meningeal involvement
9. Known sensitivity or allergy to investigational product
10. Major surgery within three weeks
11. Patients receiving organ transplantation
12. Patients with secondary tumour, excluding cured (5 years without relapse) in situ Non-melanoma skin cancer. superficial bladder cancer, in situ cervical cancer, Gastrointestinal intramucous carcinoma and breast cancer
13. Presence of Grade III nervous toxicity within past two weeks
14. Active and severe infectious diseases
15. Any potential drug abuse, medical, psychological or social conditions whichmay disturb this investigation and assessment
16. In any conditions which investigator considered ineligible for this study
17. Patients with histological transformation.