A single arm phase II trial of neoadjuvant cabazitaxel and cisplatin chemotherapy for muscle invasive transitional cell carcinoma of the urinary bladder

Introduction
Neoadjuvant cisplatin-based combination chemotherapy improves survival in muscle-invasive bladder cancer. However, response rates and survival remain suboptimal. We evaluated the efficacy, safety, and tolerability of cisplatin plus cabazitaxel.

Methods
A phase II single-arm trial was designed to recruit at least 26 evaluable patients. This would give 80% power to detect the primary endpoint, an objective response rate defined as a pathologic complete response plus partial response (pathologic downstaging), measured by pathologic staging at cystectomy (p0 = 0.35 and p1 = 0.60, α = 0.05).

Results
Objective response was seen in 15 of 26 evaluable patients (57.7%) and more than one- third of patients achieved a pathologic complete response (9/26; 34.6%). Seventy-eight percent of the patients (21/27) completed all cycles of treatment, with only 6.7% of the reported adverse events being graded 3 or 4. There were 6 treatment-related serious adverse event reported, but no suspected unexpected serious adverse reactions. In the patients who achieved an objective response, the median progression-free survival and overall survival were not reached (median follow-up of 41.5 months). In contrast, the median progression-free survival (7.2 months) and overall survival (16.9 months) were significantly worse (P = .001, log-rank) in patients who did not achieve an objective response.

Conclusion
Cabazitaxel plus cisplatin for neoadjuvant treatment of muscle-invasive bladder cancer can be considered a well-tolerated and effective regimen before definitive therapy with higher rates (57.7%) of objective response, comparing favorably to that with of cisplatin/gemcitabine (23%–26%). These results warrant further evaluation in a phase III study.