title: Synergistic antitumor effect of bispecific CD19 x CD3 and CD19 x CD16 diabodies in a preclinical model of non-Hodgkin's lymphoma.
abstract: To target NK cells against non-Hodgkin's lymphoma, we constructed a bispecific diabody (BsDb) with reactivity against both human CD19 and FcgammaRIII (CD16). Bacterially produced CD19 x CD16 BsDb specifically interacted with both CD19(+) and CD16(+) cells and exhibited significantly higher apparent affinity and slower dissociation from the tumor cells than from effector cells. It was able to induce specific lysis of tumor cells in the presence of isolated human NK cells or nonfractionated PBLs. The combination of the CD19 x CD16 BsDb with a previously described CD19 x CD3 BsDb and CD28 costimulation significantly increased the lytic potential of human PBLs. Treatment of SCID mice bearing an established Burkitt's lymphoma (5 mm in diameter) with human PBLs, CD19 x CD16 BsDb, CD19 x CD3 BsDb, and anti-CD28 mAb resulted in the complete elimination of tumors in 80% of animals. In contrast, mice receiving human PBLs in combination with either diabody alone showed only partial tumor regression. These data clearly demonstrate the synergistic effect of small recombinant bispecific molecules recruiting different populations of human effector cells to the same tumor target.
authors.affiliation: Affimed Therapeutics, Heidelberg, Germany. s.kipriyanov@affimed.com
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Kipriyanov
authors.forename: Björn
authors.initials: B
authors.lastname: Cochlovius
authors.forename: Holger J
authors.initials: HJ
authors.lastname: Schäfer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Moldenhauer
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bähre
authors.forename: Fabrice
authors.initials: F
authors.lastname: Le Gall
authors.forename: Stefan
authors.initials: S
authors.lastname: Knackmuss
authors.forename: Melvyn
authors.initials: M
authors.lastname: Little
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D000918:Antibody Specificity / Q000235:genetics; D018941:Antigens, CD19 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000138:chemical synthesis / Q000494:pharmacology*; D001666:Binding Sites, Antibody / Q000235:genetics; D015374:Biosensing Techniques; D002051:Burkitt Lymphoma / Q000276:immunology / Q000628:therapy; D017252:CD3 Complex / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D004357:Drug Synergism; D006801:Humans; D007275:Injections, Intravenous; D019169:Jurkat Cells; D007694:Killer Cells, Natural / Q000276:immunology; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D051379:Mice; D016513:Mice, SCID; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000138:chemical synthesis / Q000235:genetics / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D018033:Antibodies, Bispecific; D018941:Antigens, CD19; D000970:Antineoplastic Agents; D017252:CD3 Complex; D017452:Receptors, IgG; D011994:Recombinant Proteins