A substance being studied in the treatment of liver cancer. HuAFP31 is a monoclonal antibody that can bind to tumor cells that make a protein called alpha fetoprotein (AFP). It is linked to a radioactive substance called yttrium Y 90, which may help kill the cancer cells. Yttrium Y 90 DOTA monoclonal antibody HuAFP31 is a type of radioimmunoconjugate.

A radioimmunoconjugate comprised of the monoclonal antibody HuAFP31, directed against alpha fetoprotein, that is conjugated to the chelating agent tetra-azacyclododecanetetra-acetic acid (DOTA) and radiolabeled with the beta-emitting radioisotope Yttrium Y90. Yttrium Y 90 DOTA monoclonal antibody HuAFP31 binds to tumor cells expressing alpha fetoprotein, selectively delivering a cytotoxic dose of beta radiation.