Phase 2 study of adjuvant intravesical instillations of apaziquone for high risk nonmuscle invasive bladder cancer.

PURPOSE

We studied the safety and efficacy of multiple adjuvant apaziquone instillations in patients with high risk nonmuscle invasive bladder cancer.

MATERIALS AND METHODS

Patients with high risk nonmuscle invasive urothelial carcinoma of the bladder underwent transurethral resection of all bladder tumor(s), and received 6 weekly adjuvant intravesical apaziquone instillations of 4 mg in 40 ml. Patients with carcinoma in situ received 3 further maintenance instillations at months 3, 6 and 12. Followup consisted of cystoscopy, urine cytology and observation of adverse events every 3 months for 18 months.

RESULTS

A total of 53 patients were enrolled in the study. Although all patients were high risk according to the definitions used when the study was initiated, according to most recent guideline criteria, 80% and 20% of these patients would now be considered intermediate and high risk for recurrence, and 50% and 44% would be considered intermediate and high risk for progression, respectively. Intent to treat analysis of 49 patients with papillary tumors showed recurrent tumors in 34.7% and 44.9% at 12 and 18 months, respectively. One patient had progression to T2 or greater urothelial carcinoma after 9 months. There were 4 patients with carcinoma in situ who had complete responses at 3 months but discontinued treatment due to cystitis, recurrent papillary disease, urinary incontinence and dysuria. Most other side effects were mild (grade 1 to 2).

CONCLUSIONS

Adjuvant intravesical instillations of apaziquone are generally well tolerated. The recurrence rates of 34.7% after 12 months and 44.9% after 18 months in these patients can be considered encouraging, and warrant further study.