The addition of abiraterone acetate and prednisone (AAP) or docetaxel and prednisone (DocP) to standard of care (SOC) may improve survival outcomes in patients with high-risk prostate cancer (PCa) initiating long-term androgen deprivation therapy, according to data presented at the European Society of Medical Oncology (ESMO) 2017 Congress in Spain.1
Long-term hormone monotherapy has been the standard of care for patients with PCa for more than 60 years. The purpose of this study was to compare the efficacy of 2 new treatment standards using a patient subset of the STAMPEDE trial (ClinicalTrials.gov Identifier: NCT00268476). For this analysis, researchers simultaneously assigned 566 patients to 2 study arms where patients received SOC+AAP, or SOC+DoCP.
Patient characteristics were well balanced between the treatment arms. Median age at baseline was 66 and median PSA level was 56 ng/mL. Sixty percent of patients were classified as M1 status, 76% of patients had Gleason scores of 8 to 10, and 79% were WHO PS 0.
At a median follow-up of 4 years, there were 45 deaths in the SOC+DocP arm and 111 deaths in the SOC+AAP arm. Estimated overall survival was a hazard ratio (HR) of 1.16 with no statistically significant difference between the 2 treatment arms.
Patients in the SOC+AAP arm demonstrated a more favorable failure-free survival (HR, 0.51 [0.39-0.67]) and progression-free survival (HR, 0.65 [0.48-0.88]) compared to the SOC+DocP arm. Both the estimated treatment effects for metastases-free survival (HR, 0.77 [0.57-1.03]), and freedom from skeletal-related events (HR, 0.83 [0.55-1.25]) were also more favorable with the SOC+AAP arm but there were no statistically significant differences between the two arms.
There was no heterogeneity observed according to baseline M0 or M1 status. The toxicity results differed between the treatment arms with Grade 3, 4, and 5 toxicities occurring in 36%, 13%, and 1% of SOC+DocP patients compared to 40%, 7%, and 1% of SOC+AAP patients.
Findings from this comparative study indicate a favorable failure-free survival and progression-free survival with SOC+AAP, with less robust evidence regarding metastases-free survival and skeletal related events.
Study authors concluded that treatment choice may be driven by drug availability as well as patients’ characteristics and preferences.
- Sydes MR, Mason MD, Spears MR, et al. Adding abiraterone acetate plus prednisolone (AAP) or docetaxel for patients (pts) with high-risk prostate cancer (PCa) starting long-term androgen deprivation therapy (ADT): Directly randomised data from STAMPEDE (NCT00268476). Presented at: ESMO 2017 Congress; Madrid, Spain: September 8-12, 2017. Abstract LBA31_PR.
This article originally appeared on Cancer Therapy Advisor