A human monoclonal antibody detecting a Tumor-associated antigen (Taa) expressed on several different solid tumors and its possible use for intracavitary prophylaxis in Non Invasive Bladder Cancer (NIBC)

Aim: Production of a human monoclonal antitumour antibody for intracavitary immunoprophylaxis of non infiltrating bladder cancer. Materials and methods: A human anti-tumor-antibody-producing lymphoid cell-line was obtained by infection of peripheral blood lymphocytes (PBL) of a cancer patient with Epstein-Barr virus (EBV). Subsequently, the line has been fused with a murine myeloma and some human-antibodies- producing clones were selected by cluster picking. Results: No mouse immunoglobulins were detected. We describe here the studies performed on one of these clones, Brit-26/Hy, that produces human M and G1 class immunoglobulins reacting with a human Tumour-Associated Antigen (TAA) of 55 kDa Molecular Weight (MW). The antigen was found on cells from tumors and cell lines from different histology (Transitional Cell Carcinoma of the Bladder -TCCB-, kidney, colon and breast adenocarcinoma, glioblastoma) and does not seem to be expressed on normal cells of the corresponding tissue. Conclusions: In consideration of the high percentage of reacting TCCB cells and absence of reaction with normal transitional cells of the bladder we suggest the use of Brit-26/Hy in passive immunoprophylaxis for relapsing Non Invasive Bladder Cancer (NIBC) after transurethral resection (TUR).