Cabazitaxel-gemcitabine-cisplatin combo for BCG-unresponsive bladder cancer passes phase II trial

A phase II trial has demonstrated the safety and tolerability of combination treatment with intravesical cabazitaxel, gemcitabine, and cisplatin in patients with nonmuscle-invasive bacillus Calmette-Guérin (BCG)‒unresponsive urothelial carcinoma of the bladder.

Thirty-three patients were enrolled in this trial (median age 72 years, seven female), with a median follow-up of 30.8 months. Participants had high-grade disease and met the criteria for BCG-unresponsive disease at enrolment.

At 3 months, recurrence-free survival (RFS) was 82 percent (95 percent confidence interval [CI], 69‒95), which decreased to 73 percent (95 percent CI, 57‒87) at 12 months and further dropped to 59 percent (95 percent CI, 42‒76) at 24 months. The restricted mean survival time for RFS at 24 months was estimated to be 18.1 months (95 percent CI, 15‒21). No dose-limiting toxicities were observed.

“RFS results are excellent and may represent an improvement from many other available nonsurgical treatments for BCG-unresponsive bladder cancer,” the investigators said.

This single-centre trial included patients with BCG-unresponsive high-risk nonmuscle-invasive bladder cancer who refused or were not eligible for radical cystectomy. They received an intravesical induction course of cabazitaxel and gemcitabine weekly and cisplatin biweekly for 6 weeks.

Initial clinical response was characterized by no evidence of high-grade disease on postinduction cystoscopy with biopsy at 3 months. Patients who responded to treatment received maintenance therapy each month with cabazitaxel and gemcitabine during the first year, and bimonthly for the second year, for a total of 24 months.

Patients underwent flexible cystoscopy every 3 months, and those with any abnormalities went through rigid cystoscopy and biopsy. RFS at 12 months was the primary outcome.