Intravesical immunotoxin as adjuvant therapy to prevent the recurrence of bladder cancer

Objective To assess the intravesical application of immunotoxin as adjuvant therapy to pre vent recurrence after tumor resection in bladder cancer patients.Methods An anti-human immunotoxin against bladder carcinoma, BDI-1-RT, was prepared a nd its in vitro targeting cytotoxicity estimated.The immunoreactivity of BDI- 1-RT with human bladder cancer tissue of different grades and stages was detect ed by immunohistochemical analysis.After safety test, intravesical administrat ion of BDI-1-RT was performed in 31 patients while mitomycin C (MMC) was used in 36 patients serving as a control group.The recurrence rates and side effects in both groups were recorded.In addition, the development of human anti-m ouse antibodies (HAMA) was determined by ELISA, to assess the potential safety of this immuotoxin.Results In our study, BDI-1-RT had immunoreactivity with 81.6% of bladder transitiona l cell carcinomas.The immunoreactivity of BDI-1-RT correlated with tumor gra de.High-grade carcinoma had stronger staining than low-grade (P<0.05). There was no significant difference between the BDI-1-RT group (10%) and MMC group (19.3%) in recurrence rate (P>0.05).Side effects, including s ystemic and local, were more frequent in the MMC group (11 of 36 patients versus 2 of 31, P<0.05).HAMA was not detected in any of 7 patients.Conclusion Immunotoxin may have considerable potential in the prophylaxis of bladder transi tion cell carcinoma.