The purpose of this study is to determine whether SCT400 is safe and effective in the treatment of B-cell Non Hodgkin's lymphoma

Inclusion Criteria:

• aged from 18 to 75 years
• having histologically confirmed NHL expressing CD20 antigen
• having relapsed non-Hodgkin's lymphoma(NHL) after at least one prior course of standard therapy
• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 according to WHO scale, and expected survival of at least ≥ 3 months
• signed an informed consent form which was approved by the institutional review board of the respective medical center

Exclusion Criteria:

• single measurable lesion ≥7 cm in diameter
• with serious hematologic dysfunction (white blood cell count of <3.0×103/μL; absolute neutrophil count of <1.5×103/ μL; platelet count of < 75×103/μL; hemoglobin level of < 8.0 g/dL; serum immunoglobulin G(IgG) level of <600 mg/dL);, hepatic dysfunction (total bilirubin level of > 1.5×upper limit of normal（ULN）; aspartate amino transferase (AST) and alanine amino transferase (ALT) levels of >2.5 × ULN (≥5 × ULN for patients with liver metastases)); and renal dysfunction (serum creatinine level of > 1.5×ULN )
• having to be at least 4 weeks beyond prior anticancer therapy including corticosteroid, or participating in other clinical trial or have not recovered from significant toxicities of prior therapy
• had received rituximab or other anti-CD20(+) monoclonal antibody treatment within 1 year before enrollment
• had received hematopoietic cytokines, e.g CSF、EPO within 1 week prior to study entry
• with other malignancies ; or central nervous system (CNS) lymphoma, AIDS- related lymphoma; or active opportunistic infection, a serious nonmalignant disease
• having hepatitis B virus surface antigen and /or antibodies to hepatitis C virus or human immunodeficiency virus
• with pleural effusions or ascites secondary to lymphoma; or high risk of tumor lysis syndrome; or recent major surgery (within 28 days )
• with a history of allergic reaction or protein product allergy including murine proteins
• pregnant or lactating or not accepted birth control methods including male patients