Abstract
202 Background: Enzalutamide improve overall survival (OS) in patients with metastatic castrate resistant prostate cancer (mCRPC) patients following docetaxel treatment. Optimal sequencing and possible cross-resistance for novel mCRPC therapeutics is less understood. In this study we report biochemical response and OS after enzalutamide treatment in post-chemo mCRPC patients following progression on post-chemo abiraterone treatment. Methods: Twenty-four post-chemotherapy and post-abiraterone mCRPC patients with progressive disease received enzalutamide 160 mg/daily in a Danish compassionate-use program sponsored by Astellas Pharma A/S. Best PSA and alkaline phosphatase response was recorded. Fischer’s exact test, Mann-Whitney U test and linear regression model was used to test for differences in PSA response. OS was calculated from initiation of enzalutamide treatment. Results: Minimum follow-up was three months. The best median PSA response was -22% (-76% to 76%). Forty-six percent of patients had a greater than 30% decrease in PSA. The PSA response to enzalutamide did not correlate to the number of prior cancer treatments (p = 0.57), time from diagnosis to CRPC (p = 0.11), or prior response to docetaxel (p = 0.67). However, eight patients treated with second line cabazitaxel had an inferior PSA response to enzalutamide (p = 0.03), and there was a trend for the PSA response to abiraterone to correlate with the PSA response to the succeeding enzalutamide (B = 0.22, p = 0.05). The best median alkaline phosphatase response was 0.1% (-67% to 126%). Median OS was 4.8 months. Conclusions: Patients with post-chemotherapy, post-abiraterone mCRPC treated with enzalutamide showed less marked biochemical response to therapy compared to the results from the AFFIRM study where post-chemo abiraterone was not used. Whether this is an effect of cross-resistance or a result of the natural history of the disease needs further elaboration.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
