90Yttrium antiferritin--a new therapeutic radiolabeled antibody.

A new radiolabel 90Yttrium has been chelated to antiferritin antibodies for the treatment of hepatocellular cancer. The isotope 90Yttrium has the advantage of no significant external radiation to other individuals, that is, outpatient therapy and potentially more therapeutic power with an increase from 0.3 Mev 131I beta radiation to 0.9 Mev 90Yttrium pure beta radiation. Six patients treated in the Phase I study have had modest hematologic toxicity and two have had partial remissions of their primary tumors. One of these patients has had complete remission of a pulmonary metastasis. The use of external radiation (900 rad) to the primary tumor in advance of radiolabeled antibody administration has increased antibody uptake and increased tumor dose rate and total dose. An extensive study of 90Yttrium antiferritin is planned.