A study presented at the 2016 Genitourinary Cancers Symposium showed that 40% of patients with metastatic castration-resistant prostate cancer treated with docetaxel following abiraterone (Zytiga) had at least a 50% reduction in prostate-specific antigen (PSA), demonstrating the activity of this drug sequencing. These findings were presented at the by Thomas W. Flaig, MD, of the University of Colorado Cancer Center, and colleagues.1
The multi-institution study followed 1,088 patients treated on the clinical trial COU-AA-302. Of the patients treated with abiraterone, 67% went on to receive further therapies, with 36% receiving two additional therapies and 17% receiving three or more. About half of all abiraterone-treated patients on the study were treated with docetaxel in the next line of therapy. Of these patients receiving docetaxel after abiraterone, 40% had PSA decline by more than half, demonstrating the effectiveness of this chemotherapy even after treatment with androgen-deprivation therapy.
“Surprisingly, the next most common ‘treatment’ in this setting after docetaxel was no treatment at all,” Dr. Flaig noted.
“This confirms the activity of abiraterone followed by docetaxel and represents important data on the sequencing of medical therapies under this new paradigm,” Dr. Flaig said. ■
Disclosure: For full disclosures of the study authors, see https://coi.asco.org/Report/ViewAbstractCOI?id=156483.
1. Flaig TW, et al: Genitourinary Cancers Symposium. Abstract 168. Presented January 7, 2016.