Enzalutamide Plus ADT prolongs survival in metastatic hormone-sensitive prostate cancer
Combination of enzalutamide with androgen deprivation therapy (ADT) provides long-term survival benefit, compared to ADT alone, in patients with metastatic hormone-sensitive prostate cancer (mHSPC ), based on the final results of the ARCHES Phase 3 trial.1
These results were presented at the 2021 Congress of the European Society for Medical Oncology (ESMO) by Andrew J. Armstrong, MD, of the Duke Cancer Institute Center for Prostate & Urologic Cancers in Durham, North Carolina.
Dr Armstrong noted that enzalutamide plus ADT has been approved for the treatment of mHSPC in the United States and Europe based on previous results from the ARCHES trial (ClinicalTrials.gov Identifier: NCT02677896).
The phase 3 trial enrolled 1150 men with mHSPC. They were randomized 1: 1 to receive enzalutamide plus ADT (574 patients) or placebo plus ADT (576 patients) and were stratified by volume of disease and previous treatment with docetaxel.
In the primary analysis, enzalutamide plus ADT reduced the risk of radiographic disease progression by 61% (P <.001 and improved key secondary endpoints but overall survival data were immature at that time.>2
Based on the results of the main analysis, the study was blinded to allow crossbreeding. A total of 180 patients (31.3%) in the placebo arm were crossed over to receive enzalutamide plus ADT. The median time to cross was 21.5 months.
During ESMO 2021, Dr. Armstrong reported the results as of May 28, 2021. At this point, there have been 356 deaths – 154 in the enzalutamide arm and 202 in the placebo arm.
The median follow-up was 44.6 months. The median duration of treatment was 40.2 months in the enzalutamide arm, 13.8 months in the placebo arm and 23.9 months for the crossover patients.
Dr. Armstrong reported that patients in the enzalutamide arm had a significant delay in the need for subsequent antineoplastic therapy. The median time to subsequent treatment was not reached in the enzalutamide arm and was 40.5 months in the placebo arm (hazard ratio [HR], 0.38; 95% CI: 0.31-0.48).
Median OS was not achieved in any of the arms, but enzalutamide plus ADT significantly improved OS by 34% compared to placebo plus ADT (RR: 0.66; 95% CI: 0.53 -0.81; P <.0001 at years the os rate was in enzalutamide arm and placebo arm.>
The benefit of OS with enzalutamide was maintained regardless of disease volume, previous local treatment, disease location, Gleason score, initial prostate specific antigen level, condition functional, age and geography.
“The survival benefit does not appear to be related to differential reception of subsequent antineoplastic treatments, and the survival benefit has been observed despite the fact that 70% of patients on placebo have received life-prolonging treatment to date … , 40% of whom received enzalutamide, “said Dr. Armstrong. mentioned.
He added that the safety results of the final scan are consistent with the results of the primary scan.
There was no treatment-related fatal adverse event (AE) in the enzalutamide arm, but there was 1 in the placebo arm. More patients in the enzalutamide arm than in the placebo arm had to discontinue study treatment due to AEs – 13.8% and 5.6%, respectively.
Disclosures: This research was supported by Astellas Pharma and Pfizer. Some study authors reported affiliations with biotech, pharmaceutical and / or device companies. Please see the original reference for a full list of disclosures.
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- Armstrong AJ, Iguchi T, Azad AA, et al. ARCHES Final Overall Survival (OS) Analysis: Phase 3, randomized, double-blind, placebo-controlled (PBO) study of enzalutamide (ENZA) + androgen deprivation therapy (ADT) in men with hormone-sensitive metastatic prostate cancer (mHSPC)). Presented at: 2021 Congress of the European Society of Medical Oncology (ESMO); September 16-21, 2021. Summary LBA25.
- Armstrong AJ, Szmulewitz RZ, Petrylak DP et al. ARCHES: A randomized phase III study of androgen deprivation therapy with enzalutamide or placebo in men with hormone-sensitive metastatic prostate cancer. J Clin Oncol. 2019; 37 (32): 2974-2986. doi: 10.1200 / JCO.19.00799