A Phase I Toxicity, Pharmacology, and Dosimetry Trial of Monoclonal Antibody OKB7 in Patients With Non-Hodgkin's Lymphoma: Effects of Tumor Burden and Antigen Expression

Eighteen patients with relapsed non-Hodgkin's lym-phoma (NHL) were infused with escalating doses of monoclonal antibody (mAb) OKB7, trace-labeled with iodine-131 (1311), in order to study toxicity, pharmacol-ogy, antibody localization, and dosimetry of radioio-dine. OKB7 is a noncytotoxic mouse immunoglobulin G2b (IgG2b) mAb reactive with B cells and most B-cell NHL. Three patients each were treated at six dose levels ranging from 0.1 mg to 40 mg. All patients had radionuclide imaging and counting daily, had serial blood sampling to study pharmacokinetics, human antimouse antibody (HAMA), and circulating antigen, and had a biopsy of accessible lymphoma to deter-mine delivery of isotope to tumors and assess the effect of tumor antigen expression on mAb delivery