title: Targeting of human breast cancer by a bispecific antibody directed against two tumour-associated antigens: ErbB-2 and carcinoembryonic antigen.
abstract: Carcinoembryonic antigen (CEA) and ErbB-2 are expressed in about 50 and 30% of breast cancers, respectively. We hypothesised that targeting of these two antigens by a bispecific antibody (BAb) might provide efficient tumour uptake and prolonged tumour residence time. In the present study, we first studied the expression of CEA and ErbB-2 on primary breast tumours screened by immunohistochemistry. Of 106 primary breast cancers, 69 (65%) were positive for CEA, 20 (19%) were positive for ErbB-2, and 13 (12%) expressed both antigens. We then prepared and evaluated a BAb directed against CEA and ErbB-2. Using BIACORE technology, we showed that the BAb recognised both CEA and ErbB-2 with affinities of 0.9 x 10 and 0.8 x 10 M(-1), respectively. In vivo, BAb tumour localisation was compared with that of its parental homodimeric F(ab')(2)-ORTHO-phenylene- dimaleimide (PDM) fragments. Uptake of (125)I-BAb was lower than that of (131)I-35A7F(ab')(2)-PDM in LS174T tumours, used as a model of CEA expressing tumours, and was similar to that of (131)I-FWP51 F(ab')(2)-PDM in SKOv3 tumours, used as a model of ErbB-2 expressing tumours. In a double-positive model, the SKOv3-CEA-1B9 tumour, BAb showed a similar uptake to that of 35A7 F(ab')(2)-PDM and we demonstrated that, although BAb had double specificity, it internalised as a homodimeric anti-ErbB-2 antibody. BAb showed a greater uptake than that of FWP51 F(ab')(2)-PDM and this difference was even more important 72 h after injection with an uptake of 7.3 +/- 2.1 vs. 1.4 +/- 0.5% of the injected dose per gram of tissue. The results obtained with the BAb in the double-positive tumour-bearing nude mice suggest that targeting two distinct tumour-associated antigens on the same cell could improve tumour localisation.
authors.affiliation: EMI 0227 INSERM and GDR CNRS 2352, Université Montpellier I, Cancer Research Centre, Montpellier, France.
authors.forename: Mylène
authors.initials: M
authors.lastname: Dorvillius
authors.forename: Vèronique
authors.initials: V
authors.lastname: Garambois
authors.forename: Didier
authors.initials: D
authors.lastname: Pourquier
authors.forename: Marian
authors.initials: M
authors.lastname: Gutowski
authors.forename: Philippe
authors.initials: P
authors.lastname: Rouanet
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Mani
authors.forename: Martine
authors.initials: M
authors.lastname: Pugnière
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Hynes
authors.forename: André
authors.initials: A
authors.lastname: Pèlegrin
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D018033:Antibodies, Bispecific / Q000276:immunology* / Q000493:pharmacokinetics / Q000627:therapeutic use; D000912:Antibodies, Neoplasm / Q000276:immunology* / Q000627:therapeutic use; D000915:Antibody Affinity; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000032:analysis / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000276:immunology*; D002272:Carcinoembryonic Antigen / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D018270:Carcinoma, Ductal, Breast / Q000276:immunology / Q000473:pathology; D018275:Carcinoma, Lobular / Q000276:immunology / Q000473:pathology; D003110:Colonic Neoplasms / Q000276:immunology / Q000473:pathology; D016503:Drug Delivery Systems; D005260:Female; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000032:analysis / Q000276:immunology; D007167:Immunotherapy; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis / Q000276:immunology*; D010051:Ovarian Neoplasms / Q000276:immunology / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000276:immunology*; D020349:Surface Plasmon Resonance; D014018:Tissue Distribution; D014162:Transfection; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D018033:Antibodies, Bispecific; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007140:Immunoglobulin Fab Fragments; D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases