Phase II Clinical Trial of a Murine Monoclonal Antibody Cytotoxic for Gastrointestinal Adenocarcinoma1

A murine monoclonal antibody (MAb) which binds to human metastatic gastrointestinal adenocarcinomas can be adminis tered safely and has tumor effects in some patients. Its thera peutic effect was assessed in 20 patients with measurable advanced colorectal carcinoma that was refractory to prior sur gical resection, chemotherapy, and/or radiotherapy. All patients had agreed to receive no other therapy at the time of MAb administration and follow-up evaluation. In one patient, tumor at all known sites responded after a single i.v. injection of antibody. One other patient had a marked reduction in a hepatic metastasis where binding of 131l-labeled F(ab')2 MAb fragments was dem onstrated but not in his abdominal wall métastases where no MAb binding could be demonstrated. In a third patient, stabili zation persisting for 12 mo of an aggressively growing tumor was observed. The antibody was well tolerated in all patients, although 10 patients mounted an anti-murine immunoglobulin