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

Objective To assess the intravesical application of immunotoxin as adjuvant therapy to prevent recurrence after tumor resection in bladder cancer pati ents. Methods An anti-human immunotoxin against bladder carcinoma, BDI-1-RT, was prepared and its in vitro targeting cytotoxicity estimated. The immunoreact ivity of BDI-1-RT with human bladder cancer tissue of different grades and stages was detected by immunohistochemical analysis. After safety test, int ravesical administration of BDI-1-RT was performed in 31 patients while mit omycin C (MMC) was used in 36 patients serving as a control group. The recu rrence rates and side effects in both groups were recorded. in addition, th e development of human anti-mouse antibodies (HAMA) wars determined by ELIS A, to assess the potential safety of this immuotoxin. Results In our study, BDI-1-RT had immunoreactivity with 81.6% of bladder t ransitional cell carcinomas. The immunoreactivity of BDI-1-RT correlated wi th tumor grade. 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, inclu ding systemic and local, were more frequent in the MMC group (11 of 36 pati ents 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 o f bladder transition cell carcinoma.