Immunochemotherapy of a murine thymoma with the use of idarubicin monoclonal antibody conjugates.

Abstract

Idarubicin is a derivative of daunomycin and is characterized by the absence of the methoxyl group at the C-4 position. It has been reported to have greater therapeutic effect than daunomycin. Idarubicin was chemically coupled to a monoclonal antibody to the murine Ly-2.1 alloantigen and the cytotoxicity of the drug-monoclonal antibody conjugate versus free idarubicin was tested in vitro against Ly-2+ and Ly-2- tumor cell lines. Some loss of idarubicin activity occurred upon conjugation to the monoclonal antibody; however, antibody activity was preserved and selective cytotoxicity for the Ly-2+ cell line was observed. By contrast free idarubicin was equally cytotoxic for all cell lines (Ly-2..