Clinical activity of enzalutamide in Docetaxel-naive and Docetaxel-pretreated patients with metastatic castration-resistant prostate cancer.

ABSTRACT: Two randomized clinical trials have demonstrated a survival advantage with enzalutamide over placebo in both docetaxel (D)-pretreated and D-naïve metastatic castration-resistant prostate cancer (mCRPC) patients. Cross-resistance between androgen receptor-directed therapies and taxanes has been suggested, possibly leading to lower efficacy of enzalutamide in the post-D setting.We aimed to examine the impact of prior D treatment on the clinical activity of enzalutamide in patients with mCRPC. We retrospectively reviewed an institutional database to identify men with mCRPC treated with standard-of-care enzalutamide. Patients were classified as D-naïve or D-pretreated. The efficacy end points were prostate-specific antigen (PSA) response rates (??50% PSA decline), time to PSA progression (TTPP) and clinical/radiographic progression-free survival (PFS) in response to enzalutamide. Differences between groups (D-naïve and D-pretreated) were assessed by univariate and multivariable analyses using logistic and Cox regression models.One-hundred-seven (107) consecutive patients were included: 60 were D-pretreated and 47 were D-naïve. PSA responses were 43.2% in D-naïve patients and 25.4% in D-pretreated patients (P?=?0.089). Median TTPP was 7.2 months (95% CI?=?4.5?-?17.2) in the D-naïve group versus 2.6 mo (95% CI?=?1.9?-?3.5) in the D-pretreated group (P?

SUBMITTER: Nadal R 

PROVIDER: S-EPMC4176523 | biostudies-other | 2014 Nov

REPOSITORIES: biostudies-other