Toxicity of local, continuous and cyclic, high-dose bladder perfusion with recombinant and natural interleukin-2 in advanced cancer of the urinary bladder.

We evaluated the toxicity of high-dose local interleukin-2 (IL-2) in 18 patients not eligible for standard treatment of advanced transitional cell bladder carcinoma. Seven received continuous high-dose local natural IL-2 via pump system in the bladder for up to 420 days. 11 received cyclic high-dose local natural IL-2 or recombinant IL-2 for up to 420 days. Treatment was well tolerated and, considering the low rate of toxicity, could be offered in an outpatient setting. Except for local contrast-media hypersensitivity, no serious side-effects were observed. This study provides a basis for the non-toxic use of local IL-2 in future studies to evaluate effectiveness of the treatment or prophylaxis of patients with superficial bladder cancer in order to prevent recurrences.