Efficacy of cabazitaxel rechallenge in heavily treated patients with metastatic castration-resistant prostate cancer.

BACKGROUND: Treatment option in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel (DOC), cabazitaxel (CABA) and new hormone therapy (NHT) is limited. Rechallenge with DOC is limited because of cumulative toxicities. This study investigated the activity and safety of CABA rechallenge in mCRPC. PATIENTS AND METHODS: Clinical data were collected retrospectively in 17 centres in Europe. Eligible patients had undergone rechallenge with cabazitaxel after three previous lines of treatment (DOC, NHT and CABA, in any order). Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Data on toxicities were collected. RESULTS: A total of 69 of 562 patients (Eastern Cooperative Oncology Group performance status 0-1 69%) were rechallenged with CABA (25 mg/m2 q3w, 58%; 20 mg/m2 q3w, 27.5%; other, 14.5%) for 1-10 (median 6) cycles; 76.8% received prophylactic granulocyte colony-stimulating factor. Median radiological or clinical PFS with CABA rechallenge was 7.8 months and 11.9 months with initial CABA therapy. OS was 13.7 months (95% confidence interval [CI]: 9.3-15.7) from the first CABA rechallenge cycle, 59.9 months (47.8-67.1) from the first life-extending therapy in mCRPC and 78.3 months (66.4-90.7) from mCRPC diagnosis. Best clinical benefit was improved (34.3%) or stable (47.8%). Lack of response to rechallenge occurred in 17.9% of patients (3.1% with initial CABA). The level of prostate-specific antigen decreased by ≥ 50% in 24% of patients at rechallenge (71% with initial CABA). There was no grade ≥III peripheral neuropathy or nail disorders. CONCLUSIONS: CABA rechallenge may be a treatment option without cumulative toxicity in heavily pretreated patients with mCRPC who are still fit and had a progression >3 months after the last CABA injections.

Early objective response may not be a prognostic factor of survival for patients with metastatic urothelial carcinoma: from a retrospective analysis of a cohort of 113 patients.

BACKGROUND: This study aims to better define prognostic factors for patients with metastatic urothelial carcinoma (mUC), and to identify patients who will benefit from first-line cisplatin-based chemotherapy. We test the hypothesis that early objective response (EOR), defined as the occurrence of an objective response following 2 or 3 courses of chemotherapy, could be a prognostic factor for overall survival (OS) and thus be used to guide treatment decisions. Data from 113 patients with evaluable mUC receiving first-line cisplatin-based treatment between January 2004 and December 2006 was collected retrospectively from prospectively-maintained databases across seven French cancer centers. Clinical factors potentially associated with survival and EOR were analyzed in univariate and multivariate analysis. RESULTS: One hundred three patient records were complete and available for inclusion in the multivariate model. Four factors were independently associated with OS: Performance status 1 and 2 (HR 2.3 [95 % CI 1.3-3.9], p = 0.002; HR 3.4 [95 % CI 1.6-7.2], p = 0.001 respectively); presence of visceral metastases (HR 2.2 [95 % CI 1.3-3.9], p = 0.004); abnormal hemoglobin levels (HR 1.7 [95 % CI 1.01-2.8], p = 0.045); disease progression (HR 10.1 [95 % CI 4.2-24.1], p < 0.001). CONCLUSIONS: This study confirms the prognostic factors previously reported in first-line chemotherapy for mUC. However, we failed to demonstrate that EOR was an independent predictive factor of OS. Nevertheless, an early response evaluation is recommended since early progression is an important parameter that can be used to decide whether treatment should be interrupted and changed for alternative strategies integrating the concept of personalized medicine or new immune therapies.