Study of ADCT-402 in Patients With Relapsed or Refractory B-cell Lineage Non Hodgkin Lymphoma (B-NHL)

Inclusion Criteria: * Male or female participants, ages 18 years or older with pathologically confirmed relapsed or refractory B-cell lineage NHL who have failed or are intolerant to established therapy, or for whom no other treatment options are available. * Refractory or relapsed B-cell NHL (per World health Organization \[WHO\] Classification system). * Availability of formalin-fixed paraffin-embedded (FFPE) tumor tissue block. * Measurable disease, as defined by the 2014 Lugano Classification. * Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2. * Absolute neutrophil count (ANC) ≥1000/μL. * Platelet count of ≥75000/μL. * Hemoglobin ≥9.0 g/dL without transfusion within the 2 weeks prior to Day 1. * Serum/plasma creatinine ≤1.5 mg/dL. * Serum/plasma alkaline phosphatase, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) ≤2 times the upper limit of normal (ULN); ≤ 5 times ULN if there is liver or bone involvement. * Total serum/plasma bilirubin ≤1.5 times ULN. * Negative blood or urine beta-human chorionic gonadotropin (β-HCG) pregnancy test within 7 days prior to Day 1 for women of childbearing potential. * Males, and female participants who are biologically capable of having children, must agree to use a medically acceptable method of birth control. Exclusion Criteria: * Participants who have any option for other treatment for B-cell NHL at the current state of disease. * Active graft-versus-host disease. * Autologous or allogenic tr…