- Histologically documented CD20 and CD22 positive diffuse large B-cell lymphoma, according to WHO classification. CD20 and CD22 immunophenotyping at initial diagnosis is acceptable. If such prior documentation is not available, then the immunophenotyping at relapse must be established by fine-needle aspirate or biopsy or by circulating CD20 and CD22 positive NHL cells from peripheral blood during screening. Upon registration the pathological report confirming the diagnosis, must be available