ORLANDO, FL, USA (UroToday.com) - This poster presented a post hoc analysis of the COU-AA-302 trial examining outcomes related to the administration of taxane chemotherapy (i.e. docetaxel, cabazitaxel) as the therapy subsequent to abiraterone acetate (AA) in men with metastatic castration-resistant prostate cancer (mCRPC). COU-AA-302 was a randomized, double-blind, placebo-controlled trial published in 2014 which demonstrated improved radiographic progression-free survival (PFS) and overall survival (OS) with AA administration with prednisone in chemotherapy-naïve mCRPC patients.
This poster presentation looked at patients who progressed in the AA arm, focusing on outcomes of those patients receiving taxane therapy as their subsequent treatment. A total of 265 of the 502 patients (53%) in the AA arm who demonstrated progression of disease went on to receive taxane therapy as their next step, predominantly docetaxel (261 patients). The authors found that taxane chemotherapy demonstrated efficacy in this setting with greater than 50% PSA decline seen in 47% of patients. The median time to PSA progression observed was 7.59 months, however the authors caution that interpretation of this data is limited given an 87% censoring rate. The most common reason for discontinuation of taxane therapy was for progressive disease, either clinical (15%), radiographic (14%) or PSA-based (29%).
Multiple agents have become available in the last 5 years for mCRPC, and to date few studies are available to help answer the question of what the appropriate sequencing of these agents should be. This study demonstrates that taxane chemotherapy retains some antitumor efficacy following the use of AA and thus this sequence appears to be a viable strategy. Further studies will be required to assess whether this sequence is optimal or some other sequence or combination of agents for mCRPC patients.
Presented by Johann Sebastian De Bono, Matthew Raymond Smith, Fred Saad, Dana E. Rathkopf, Peter F.A. Mulders, Eric Jay Small, Neal D. Shore, Karim Fizazi, Peter De Porre, Thian San Kheoh, Jinhui Li, Mary Beth Todd, Thomas W. Griffin, and Charles J. Ryan at the 2015 Genitourinary Cancers Symposium - "Integrating Biology Into Patient-Centric Care" - February 26 - 28, 2015 - Rosen Shingle Creek - Orlando, Florida USA
The Institute of Cancer Research and The Royal Marsden Hospital, Sutton, UK; Harvard Medical School and Massachusetts General Hospital Cancer Center, Boston, MA; University of Montréal, Montréal, Québec, Canada; Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, NY; Radboud University Medical Centre, Nijmegen, The Netherlands; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA; Carolina Urologic Research Center, Atlantic Urology Clinics, Myrtle Beach, SC; Institut Gustave Roussy, University of Paris Sud, Villejuif, France; Janssen Research & Development, Beerse, Belgium; Janssen Research & Development, San Diego, CA; Johnson & Johnson Medical China, Shanghai, China; Janssen Global Services, Raritan, NJ; Janssen Research & Development, Los Angeles, CA
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Reported by Timothy Ito, MD, medical writer for UroToday.com