Edrecolomab (monoclonal antibody 17-1A)

Edrecolomab is a mouse-derived monoclonal IgG2a antibody. It recognises the human tumour-associated antigen CO17-1A which is expressed on the cell surface of a wide variety of tumours and normal epithelial tissue. Edrecolomab is thought to destroy tumour cells by activating an array of endogenous cytotoxic mechanisms, including antibody-dependent cell-mediated cytotoxicity and possibly antibody-dependent complement-mediated cytotoxicity. Edrecolomab may induce antitumour activity indirectly by inducing a host anti-idiotypic antibody response. Adjuvant therapy with edrecolomab (500 mg initial dose followed by four 100 mg infusions administered at 4-weekly intervals) significantly improved survival and reduced the tumour recurrence rate in patients with resected Dukes' stage C colorectal cancer and minimal residual disease. Data from several small clinical trials suggest that edrecolomab given as monotherapy or in combination with other antineoplastic agents has limited efficacy in the treatment of advanced colorectal or pancreatic tumours. However, results from a small phase I study in patients with advanced breast cancer were more promising. Edrecolomab was generally well tolerated in clinical trials. In a postmarketing surveillance study, the most common adverse events associated with edrecolomab were flushing/erythema and gastrointestinal symptoms including diarrhoea, abdominal pain and nausea and vomiting. Because edrecolomab is of murine origin, anaphylactic reactions have developed in some patients treated with the drug.