Randomised, double-blind, parallel group study to compare PK and PD profiles between HLX01 and rituximab (MabThera®) in patients with CD20+ B-cell Lymphoma.

Inclusion Criteria:

1. aged from 18 to 65 years;
2. CD20-positive non-Hodgkin's lymphoma (NHL);
3. having obtained CR (complete remission) or CRu (uncertain complete remisson) after the prior therapy;
4. ECOG performance status of <=1, expected survival of at least >= 3 months;
5. Peripheral blood lymphocyte count < 5×10^9/L
6. signed an informed consent form which was approved by the institutional review board of the respective medical center .

Exclusion Criteria:

1. Other invasive malignancies within 5 years except for adequately treated basal cell or squamous cell skin cancer, in situ carcinoma of the cervix;
2. Chemotherapy within 1 month;
3. Had received rituximab or other anti-CD20(+) monoclonal antibody treatment within 1 month before enrollment;
4. Had received rituximab or other anti-CD20(+) monoclonal antibody treatment 1 month ago but with ADA(+) before enrollment;
5. Blood concentration of Rituximab> 24 μg/ml prior to study entry;
6. Had received hematopoitic growth factor within 1 week prior to study entry;
7. Receipt of a live/attenuated vaccine within 4 weeks prior to the Screening Visit;
8. Recent major surgery (within 8 weeks prior to screening, excluding lymph node biopsy);
9. Peripheral or central nervous system disease;
10. Serious hematologic dysfunction (white blood cell count of <3.0×109/L; absolute neutrophil count of <1.5×109/L; platelet count of < 100×109/L; hemoglobin level of < 9.0 g/dL);
11. Hepatic dysfunction (total bilirubin level of > 1.5 × upper limit of normal (ULN); aspartate amino transferase (AST) and alanine amino transferase (ALT) levels of > 2.0 × ULN; alkaline phosphatase > 3.0 × ULN; renal dysfunction (serum creatinine level of > 1.5×ULN );
12. Abnormal thyroid function;
13. Seropositive for HIV , HCV antibody; seropositive for hepatitis B virus surface antigen (HBsAg). HBV DNA>1.0×103copies/ml;
14. Serious underlying medical conditions, could impair the ability of the patient to participate in the trial (including but not limited to ongoing active infection, uncontrolled diabetes mellitus, significant cardiac disease, uncontrolled angina, gastric ulcers, active autoimmune disease);
15. Pregnancy or breast feeding. For women of childbearing potential.
16. History of a severe allergic reaction or anaphylactic reaction to a biological agent or history of hypersensitivity to any component of the trial drug.
17. Subjects had a history of alcoholism or drug abuse;
18. Researchers think that do not fit into the group.