Colorectal carcinoma metastases: detection with In-111-labeled monoclonal antibody CCR 086

A phase I/II clinical trial with indium-111-labeled antimucin murine monoclonal antibody (MoAb) CCR 086 was conducted. Seventeen patients with histologically proved colorectal carcinoma and known metastatic disease underwent external scintigraphy after administration of 5.5 mCi (203.5 MBq) of In-111 CCR 086 at doses of 5 and 20 mg. Of 25 known lesions, 17 were detected (sensitivity, 68%). The smallest detected lesion in the lung was 1 cm and in the liver was 1.5 cm. The serum half-life of In-111-labeled CCR 086 MoAb was approximately 64 hours. The formation of human antimouse antibody (HAMA) was detected in the serum of four of five patients who received 20 mg of MoAb. No HAMAs were detected in four patients receiving 5 mg of MoAb. No side effects were encountered. Because of effective detection of liver and lung metastases with lower doses (5-20 mg) of CCR 086 conjugated with In-111, further investigations are warranted to assess clinical and therapeutic potentials of CCR 086 in the management of colorectal cancer.