Characterization of a Novel Humanized Anti-CD20 Antibody with Potent Anti-Tumor Activity against Non-Hodgkin's Lymphoma

• Published in: Cellular physiology and biochemistry Vol. 32; no. 3; pp. 645 - 654
• Main Authors: Zhang, Haifeng, Song, Liping, Ye, Hongtu, Hu, Lide, Liang, Wenlu, Liu, Datao
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Cell Physiol Biochem Press GmbH & Co KG 01-01-2013
• Subjects: Amino Acid Sequence; Animals; Anti-CD20 antibody; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - therapeutic use; Antibodies, Monoclonal, Humanized - immunology; Antibodies, Monoclonal, Humanized - therapeutic use; Antibodies, Monoclonal, Humanized - toxicity; Antibodies, Monoclonal, Murine-Derived - chemistry; Antibodies, Monoclonal, Murine-Derived - immunology; Antibodies, Monoclonal, Murine-Derived - therapeutic use; Antigens, CD20 - immunology; Antineoplastic Agents - immunology; Antineoplastic Agents - therapeutic use; Antineoplastic Agents - toxicity; Binding Sites, Antibody; Cell Line, Tumor; Cell Survival - drug effects; Complementarity Determining Regions - chemistry; Humanization; Humans; Immunogenicity; Lymphoma, Non-Hodgkin - drug therapy; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Docking Simulation; Molecular Sequence Data; Non-Hodgkin’s lymphoma; Original Paper; Rituximab; Transplantation, Heterologous; Non-Hodgkin’s lymphoma; Anti-CD20 antibody; Immunogenicity; Humanization
• ISSN: 1015-8987; 1421-9778
• DOI: 10.1159/000354468

Background: Rituximab, a mouse Fab and human Fc chimeric antibody, has been widely used to treat Non-Hodgkin's lymphoma (NHL). However, only 48% of patients respond to the treatment and complete response rate is below 10%. Also, immunogenicity was reported in 17-20% patients receiving the treatment, making it unsuitable for long term diseases such as autoimmune disorders. It has been a hot research field to “humanize” rituximab toward improved efficacy and reduced immunogenicity. Methods: In this study, an advanced antibody humanization technology was applied to the sequence of the anti-CD20 antibody 2B8, its sequence of which was based on the original murine monoclonal antibody of rituximab in Roche. The complementarity-determining regions (CDRs) of the humanized antibodies were further optimized through computer-aided molecular dock. Results: Five novel humanized anti-CD20 antibodies 1-5(1635, 1534, 3637, 1634 and 1536) were generated and their immunogenicity was significantly decreased when compared to rituximab. The novel humanized anti-CD20 antibodies 1-5 retained the binding activity of their murine counterpart, as demonstrated by the fluorescence-activated cell-sorting analysis (FACS). When compared to rituximab, the humanized antibodies still have the similar properties on both complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Furthermore, its anti-tumor efficacy in xenograft model is comparable to that of rituximab. Conclusion: The humanized anti-CD20 antibodies 1-5 have lower immunogenicity than rituximab. And at the same time, they still retain the anti-tumor effect both in vitro and vivo.