ASCO GU 2018: Addition of docetaxel to first-line long-term hormone therapy in prostate cancer (STAMPEDE)

San Francisco, CA ( Dr. Nicholas James presented results from the STAMPEDE trial for the addition of docetaxel to first-line hormonal therapy for patients with prostate cancer. Results from large randomized controlled trials (RCTs) have shown that adding docetaxel to standard of care in men initiating hormone therapy for prostate cancer prolongs survival for those with metastatic disease and prolongs time to treatment failure for those without metastatic disease [1-3]. The objective of this study was to establish whether adding docetaxel to standard of care represents a cost-effective use of healthcare resources in M0 and M1 among prostate cancer patients in the STAMPEDE trial.

STAMPEDE inclusion criteria included men with locally advanced or metastatic prostate cancer, including newly diagnosed with N1 or M1 disease, or any two of the following: stage T3/4, PSA ≥ 40 ng/mL, or Gleason score 8-10. Patients undergoing prior radical prostatectomy or radiation therapy were eligible if they had more than one of the following: PSA ≥ 4 ng/mL and PSADT < 6 months, PSA ≥ 20 ng/mL, N1, or M1 disease. Treatment with radiation therapy was mandated in patients with N0M0 disease, while strongly encouraged for N1M0 patients. Docetaxel (75 mg/m2) was administered alongside standard of care for six 3-weekly cycles with prednisolone 10 mg daily. The primary outcome for the docetaxel arm of the STAMPEDE trial [1] was overall survival (OS) and secondary outcomes included failure-free (FFS), progression-free survival (PFS), metastatic PFS (MPFS), skeletal-related events (SREs), toxicity, cost-effectiveness and quality of life.  Health outcomes and costs in the UK NHS were modelled using EuroQol (EQ-5D) and resource use data collected within the STAMPEDE trial. Lifetime predictions of costs, changes in predicted survival duration, quality adjusted life years (QALYs), and incremental cost effectiveness ratios (ICERs) were calculated.

Compared to patients allocated standard of care, docetaxel was estimated to extend predicted survival by an average of 0.89 years for M1 patients and 0.78 years for M0 patients. Docetaxel was estimated to extend discounted QALYs by 0.51 years in M1 patients and 0.39 years in M0 patients. QALY gains in M0 patients were driven by the beneficial effect of delayed and reduced relapse – ie. patients receiving docetaxel spend more time in the hormone sensitive state without treatment failure and less time with CRPC. Docetaxel was cost-effective both in M1 patients (ICER = £5,514/QALY vs. standard of care) and M0 patients (higher QALYs, lower costs vs. standard of care). The probabilistic sensitivity analysis indicated a very high probability (> 99%) that docetaxel is cost-effective in both M0 and M1 patients. Docetaxel remained cost effective in M0 patients even when no survival advantage was assumed due to reductions and delays in relapse.

Dr. James concluded that docetaxel improves overall health-related quality of life, delays time to, and reduces the need for, subsequent therapy, and is cost-effective, amongst patients with both non-metastatic and metastatic disease. According to Dr. James, clinicians should consider whether the evidence is now sufficiently compelling to support docetaxel use in non-metastatic patients, particularly as it predicts an eventual survival gain. 

1. James ND, Sydes MR, Clarke NW, et al. Addition of docetaxel, zoledronic acid, or both to first-line long-term hormone therapy in prostate cancer (STAMPEDE): survival results from an adaptive, multiarm, multistage, platform randomised controlled trial. Lancet. 2016;387(10024):1163-1177.

2. Sweeney CJ, Chen YH, Carducci M, et al. Chemohormonal Therapy in Metastatic Hormone-Sensitive Prostate Cancer. N Engl J Med. 2015;373(8):737-746.

3. Gravis G, Boher JM, Joly F, et al. Androgen Deprivation Therapy (ADT) Plus Docetaxel Versus ADT Alone in Metastatic Non castrate Prostate Cancer: Impact of Metastatic Burden and Long-term Survival Analysis of the Randomized Phase 3 GETUG-AFU15 Trial. Eur Urol. 2016;70(2):256-262.

Presented by: Nicholas D. James, Institute of Cancer and Genomic Sciences University Hospitals Birmingham Edgbaston, Birmingham, United Kingdom

Co-Authors: Beth Woods, Eleftherios Sideris, Melissa Ruth Spears, David P. Dearnaley, Malcolm Mason, Noel Clarke, Mahesh K B Parmar, Matthew Robert Sydes, Mark Sculpher, STAMPEDE Investigators

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA