Pathological response rates and quality of life outcomes of neoadjuvant cabazitaxel and cisplatin chemotherapy for muscle-invasive transitional cell carcinoma of the urinary bladder.

Abstract

5030 Background: Neoadjuvant cisplatin-based combination chemotherapy (NAC) improves survival in muscle invasive bladder cancer (MIBC). However, response rates and survival remain suboptimal. We sought to evaluate the efficacy, safety and tolerability of cisplatin cabazitaxel combination in this patient group. Methods: A phase 2 single arm trial (Simon 2 stage), to recruit at least 26 evaluable patients was designed with 80% power to detect the primary endpoint, objective response rate (ORR) of > 35%. ORR was defined as pathological complete response (pCR) plus partial response (pathological downstaging), measured by pathologic staging (T2 or greater at diagnosis, to T1 or less at radical cystectomy). Treatment was with Cisplatin 70mg/m2 and Cabazitaxel 15mg/m2 on day 1 of a 21 day cycle, for 4 cycles prior to surgery. Toxicity was recorded using CTCAE v.4.03. Quality of Life (QoL) data were collected at baseline, prior to each cycle of chemotherapy and at 3-5 weeks after 4th cycle of chemotherapy using EQ-5D and EORTC QLQ-C30, BLM30 questionnaires. Results: Objective response was seen in 15 out of 26 evaluable patients, 57.7% and over a third of patients achieved pCR (9/26; 34.6%). 78% (21/27) of patients completed all cycles of treatment, with only 6.7% of the reported adverse events (AEs) being graded 3 or 4. There were 6 treatment related SAEs reported but no SUSARs. In patients who achieved objective response the median progression free (PFS) and overall survival (OS) were not reached (median follow up: 41.5m). In contrast, median PFS (7.2m) and OS (16.9m) were significantly worse (p = 0.001) in patients who did not respond. Response rates for EORTC QLQ-C30, BLM 30 and EQ5D questionnaires was 70.4, 70.4 & 63% respectively, at end of treatment. There was no significant difference in EORTC QLQ C30 summary, global health scores and EQ5D score with treatment. There was a significant decline in mean QLQ C30 domain scores after 1st cycle compared to baseline, but no further deterioration with subsequent cycles of chemotherapy. Conclusions: Cabazitaxel with cisplatin as NAC of MIBC can be considered a safe, well-tolerated and effective regimen with higher pCR rate of 34.6%. This compares favorably to that with Cisplatin/Gemcitabine (23-26%). Minimal changes in Global Health & EQ5D observed during NAC further demonstrates the excellent tolerability of this regimen and to our knowledge are the first data regarding QoL in NAC in MIBC. These results warrant further evaluation in a larger phase 3 study. Clinical trial information: 2011 004090 82 .