Objectives: To ascertain the side effects of intravesical instillation of pertussis toxin (PTX) because it inhibits tumor cell motility in vitro and in vivo and seems to be a promising therapeutic approach against cancer.
Methods: We initiated a Phase I study and measured the effect of intravesical instillation of PTX before radical cystectomy. Study end points were PTX-related side effects. PTX was instilled at five dose levels, starting with 14 microg and continuing to 72 microg.
Results: Fifteen patients, with a median age of 64 years, were included in the study. Intravesical instillation of PTX was without local or systemic side effects (grade 0, according to National Cancer Institute toxicity criteria).
Conclusions: Treatment with PTX was safe and well tolerated without any significant local or systemic toxicity in dosages up to 72 microg. Therefore, the influence of PTX on local tumor should be evaluated in a Phase II study.