Intravesical administration of tumor-associated monoclonal antibody AUA1 in transitional cell carcinoma of the bladder: a study of biodistribution

Summary

Forty-five patients known or suspected to have transitional cell carcinoma of the urinary bladder underwent intravesical administration of either AUA1 tumor-associated monoclonal antibody or 11.4.1. nonspecific monoclonal antibody. Antibodies were radiolabeled with iodine-131, diluted in 50 ml normal saline and remained in the bladder for up to 1 h. During cystoscopy or transurethral resection of the tumor, tissue samples were taken from normal and malignant areas and were counted for radioactivity in a gamma counter. Blood samples were also measured for radioactivity. Mean uptake of AUA1 at 2, 20, 40 and 60 h after administration (expressed as 10³ x percentage of injected dose/gram of tissue) was: 1.77±3.2, 1.28=1.67, 0.72±0.94 and 0, respectively in the tumor and 0.79±0.83, 0.14±0.34, 0.033±0.06, and 0 in normal tissue. Mean uptake of 11.4.1 at 2 and 20 h was: 0.47±0.42 and 0.018±0.015, respectively, in tumor and 0.2±0.19 and 0.013±0.002 in normal samples. No remarkable radioactivity was found in blood samples. Conventional and immunoperoxidase staining were also performed. Mean uptake of AUA1 by the tumor increased as the degree of tumor differentiation decreased. Our findings indicate that intravesical administration of AUA1 results in selective immunolocalization of AUA1 in intermediate and high-grade transitional cell carcinoma. This may allow the development of a new method for bladder carcinoma treatment or prophylaxis against recurrence.