Abiraterone in "High-" and "Low-risk" Metastatic Hormone-sensitive Prostate Cancer

Publication

Abiraterone in "High-" and "Low-risk" Metastatic Hormone-sensitive Prostate Cancer

Journal Paper/Review - Aug 23, 2019

Hoyle Alex P, Aebersold Daniel M, Jones Rob J, Matheson David, Millman Robin, Mason Malcolm D, Ritchie Alastair W S, Russell Martin, Douis Hassan, Parmar Mahesh K B, Sydes Matthew R, Clarke Noel W, Gillessen Sommer Silke, Ingleby Fiona, Ali Adnan, James Nicholas D, Cook Adrian, Parker Christopher C, de Bono Johann S, Attard Gerhardt, Chowdhury Simon, Cross William R, Dearnaley David P, Brawley Christopher D, Gilson Clare, STAMPEDE Investigators

Citation

Hoyle A, Aebersold D, Jones R, Matheson D, Millman R, Mason M, Ritchie A, Russell M, Douis H, Parmar M, Sydes M, Clarke N, Gillessen Sommer S, Ingleby F, Ali A, James N, Cook A, Parker C, de Bono J, Attard G, Chowdhury S, Cross W, Dearnaley D, Brawley C, Gilson C, STAMPEDE Investigators. Abiraterone in "High-" and "Low-risk" Metastatic Hormone-sensitive Prostate Cancer. Eur Urol 2019; 76:719-728.

Type

Journal Paper/Review (English)

Journal

Eur Urol 2019; 76

Publication Date

Aug 23, 2019

Issn Electronic

1873-7560

Pages

719-728

Brief description/objective

BACKGROUND
Abiraterone acetate received licencing for use in only "high-risk" metastatic hormone-naïve prostate cancer (mHNPC) following the LATITUDE trial findings. However, a "risk"-related effect was not seen in the STAMPEDE trial. There remains uncertainty as to whether men with LATITUDE "low-risk" M1 disease benefit from androgen deprivation therapy (ADT) combined with abiraterone acetate and prednisolone (AAP).

OBJECTIVE
Evaluation of heterogeneity of effect between LATITUDE high- and low-risk M1 prostate cancer patients receiving ADT + AAP in the STAMPEDE trial.

DESIGN, SETTING, AND PARTICIPANTS
A post hoc subgroup analysis of the 2017 STAMPEDE "abiraterone comparison". Staging scans for M1 patients contemporaneously randomised to ADT or ADT + AAP within the STAMPEDE trial were evaluated centrally and blind to treatment assignment. Stratification was by risk according to the criteria set out in the LATITUDE trial. Exploratory subgroup stratification incorporated the CHAARTED criteria.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS
The primary outcome measure was overall survival (OS) and the secondary outcome measure was failure-free survival (FFS). Further exploratory analysis evaluated clinical skeletal-related events, progression-free survival (PFS), and prostate cancer-specific death. Standard Cox-regression and Kaplan-Meier survival estimates were employed for analysis.

RESULTS AND LIMITATIONS
A total of 901 M1 STAMPEDE patients were evaluated after exclusions. Of the patients, 428 (48%) were identified as having a low risk and 473 (52%) a high risk. Patients receiving ADT + AAP had significantly improved OS (low-risk hazard ratio [HR]: 0.66, 95% confidence interval or CI [0.44-0.98]) and FFS (low-risk HR: 0.24, 95% CI [0.17-0.33]) compared with ADT alone. Heterogeneity of effect was not seen between low- and high-risk groups for OS or FFS. For OS benefit in low risk, the number needed to treat was four times greater than that for high risk. However, this was not observed for the other measured endpoints.

CONCLUSIONS
Men with mHNPC gain treatment benefit from ADT + AAP irrespective of risk stratification for "risk" or "volume".

PATIENT SUMMARY
Coadministration of abiraterone acetate and prednisolone with androgen deprivation therapy (ADT) is associated with prolonged overall survival and disease control, compared with ADT alone, in all men with metastatic disease starting hormone therapy for the first time.