Study of IMM0306 in Patients With Relapsed or Refractory CD20-positive B-cell Non-Hodgkin's Lymphoma

Inclusion Criteria: * Relapsed or refractory CD20-positive B-cell non-Hodgkin's lymphoma (B-NHL) that has been diagnosed, including but not limited to diffuse large B-cell lymphoma (DLBCL) Follicular lymphoma (FL), mucosal lymphoma (MALT-L), small lymphocytic lymphoma (SLL) / chronic lymphocytic leukemia (CLL). * At least one measurable or assessable tumor lesion. * Adequate organ and hematologic function. * Eastern Co-operative Oncology Group (ECOG) score 0 to 2. * All adverse events from prior treatment must be CTCAE v5.0 grade \<= 1 Exclusion Criteria: * Active central nervous system (CNS) lymphoma. * Systemic steroid therapy (dose equivalent to \> 10 mg prednisone / day). * History of severe allergic reactions to macromolecular protein preparations/monoclonal antibodies and any test drug components (CTCAE v5.0 grade \>=3). * Have evidence of severe uncontrollable active infection. * Subjects have deep vein embolism or pulmonary embolism within 6 months before screening.