Capture of recombinant ricin A chain by a bispecific anti-RTA:anti-CEA monoclonal antibody pre-targeted to a human gastric carcinoma xenograft in nude mice

A bispecific antibody against carcinoembryonic antigen (CEA) and ricin A chain has been shown to localise in a CEA-producing human tumour xenograft. When labelled recombinant ricin A chain was subsequently injected there was uptake into tumours, indicating that this bispecific antibody can capture or carry toxin into tumour deposits.