title: Obinutuzumab: a new class of anti-CD20 monoclonal antibody.
abstract: OBJECTIVE
  Obinutuzumab is a new anti-CD20 monoclonal antibody which demonstrated clinical superiority compared with rituximab in a recent phase III study. There is a need to better understand how this antibody differs from rituximab and why it could modify the landscape of the treatment of CD20 malignancies in the near future.
  
  
  RESULTS
  Antibody-dependent cellular cytotoxicity plays a critical role in clinical activity of rituximab. To increase antibody-dependent cellular cytotoxicity, a strategy improving the affinity between the Fc portion of the antibody and FcγRIIIa expressed by effector cells has been recently developed. This strategy modifies the carbohydrate located between the two Fc arms. Thus, the lack of fucose on IgG oligosaccharide improves binding to FcγRIII and antibody-dependent cellular cytotoxicity. Obinutuzumab recognized a CD20 epitope different from that bound by rituximab. This property confers different features to obinutuzumab mechanisms of action with a noncaspase-dependent direct-cell death and the lack of complement-dependent cytotoxicity. Obinutuzumab demonstrated significant activity in animal models, and phase I or II studies showed clinical activity in different subtypes of CD20 diseases.
  
  
  CONCLUSIONS
  Obinutuzumab, a type II glycoengineered monoclonal antibody, is characterized by an increased antibody-dependent cellular cytotoxicity and direct-cell death but no complement-dependent cytotoxicity. Recent clinical data demonstrated a superiority of obinutuzumab compared with rituximab, suggesting that this antibody should be, in the future, the backbone of the treatment of B-lymphoproliferative disorders.
authors.affiliation: aUMR CNRS 5235, Université Montpellier, Montpellier bLabex MAbImprove, Faculté de Médecine de Tours, Tours cDépartement d'Hématologie Clinique, Centre Hospitalier Régional Universitaire (CHRU) de Montpellier, Montpellier, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Gagez
authors.forename: Guillaume
authors.initials: G
authors.lastname: Cartron
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized / Q000276:immunology* / Q000494:pharmacology; D018951:Antigens, CD20 / Q000276:immunology*; D016923:Cell Death / Q000187:drug effects; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000188:drug therapy / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018951:Antigens, CD20; C543332:obinutuzumab