Document Type

Article

Department

Haematology and Oncology, East Africa

Abstract

Twelve patients with metastatic colorectal cancer participated in a Phase I trial of 1311-labeled chimeric B72.3 (human IgG4). Consecutive groups of patients received 18 mCi/m 2, 27 mCi/ m 2 and 36 mCi/m a. No acute side effects related to antibody administration were noted. Bone marrow suppression was the only side effect; it was dose-dependent and correlated with whole-body radiation dose estimates. The lowest dose level produced no marrow suppression, whereas 27 mCi/m 2 resulted in Grade 1 and 2 marrow suppression in two of three patients. The maximum tolerated close was 36 mCi/m 2 with all six patients at this dose level having at least Grade 1 and two patients with Grade 3 and 4 marrow suppression. Eight of 12 patients had radioimmune imaging of tumor sites at 5- 22 days. Seven patients had an antibody response to initial infusion. On retreatment, whole-body kinetics and imaging were altered for patients with a high anti-ch-B72.3 response. Thus, chimeric B72.3 (IgG4) has limited utility as a means of delivering multiple therapeutic doses of 1311 in the majority of patients; alternative strategies including second generation anti-TAG-72 monoclonal antibodies, other radioisotopes and other chimeric human isotypes will need to be pursued.

Comments

This work was published before the author joined Aga Khan University.

Publication (Name of Journal)

Journal of Nuclear Medicine

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