111In-DOTA-anti-CEA diabody

111In-DOTA-anti-CEA diabody is a radiopharmaceutical imaging agent designed for the detection of tumors expressing carcinoembryonic antigen (CEA), such as colorectal carcinoma. It consists of a bivalent antibody fragment (diabody) derived from the T84.66 antibody, which targets CEA with high affinity. The diabody is conjugated to the chelator DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) and radiolabeled with the gamma-emitting isotope indium-111 (^111In). With a molecular weight of approximately 50-55 kDa, the diabody format offers rapid blood clearance and high tumor penetration compared to intact antibodies, facilitating high-contrast radioimmunoimaging (SPECT). Preclinical studies conducted primarily at the City of Hope National Medical Center demonstrated high tumor uptake but also significant renal retention of the radiolabel, leading to the subsequent development of PEGylated variants to optimize pharmacokinetics.

Other names

111In-DOTA-T84.66 diabodyIndium-111 DOTA-anti-CEA diabodyIndium111 DOTA-anti-CEA diabodyIndium 111 DOTA-anti-CEA diabody111In-labeled anti-CEA diabody