Phase II marker lesion study with intravesical instillation of apaziquone for superficial bladder cancer: toxicity and marker response

Purpose: We studied the ablative activity of intravesical apaziquone (EOquin™) on a papillary marker tumor and determined the incidence of side effects. Materials and Methods: A total of 46 patients with multiple pTa or pT1 bladder tumors underwent visible lesion resection except for 1 marker tumor. Patients were then treated with 6 instillations of apaziquone at weekly intervals. The response was determined 2 to 4 weeks after the last instillation. Results: One patient withdrew informed consent and refused the last treatment due to side effects. A histologically proven complete response was seen in 30 patients. Progression to invasive stage was not observed. Local side effects in this study were comparable to those due to other chemotherapy instillations, such as mitomycin C and epirubicin, but less severe and less frequent compared to those of bacillus Calmette-Guerin instillations. Conclusions: The histological complete response rate after 6 consecutive instillations of apaziquone in patients with superficial bladder cancer was 67% (95% CI 51 to 80). Local side effects were comparable to side effects due to other chemotherapy instillations.