ESMO Virtual Congress 2020: The PROSPER Trial, Nonmetastatic Castration - Resistant Prostate Cancer, Outcomes by Prostate - PSA Response

( There has been a rapid evolution in treatment options for patients with non-metastatic castration-resistant prostate cancer (nmCRPC) since the spring of 2018. Up until the presentation of SPARTAN and PROSPER trials, reporting on the use of apalutamide and enzalutamide in non-metastatic castration-resistant prostate cancer, at GU ASCO in February 2018, there were no specifically approved treatment options for these patients. These agents, as well as darolutamide, were subsequently approved on the basis of demonstrated improvements in metastasis-free survival (MFS). At ASCO 2020, updated results of the PROSPER trial were presented demonstrating improvements in overall survival for patients with nmCRPC randomized to enzalutamide and androgen deprivation therapy, as compared to androgen deprivation therapy (ADT) alone. 

In a poster presentation at this year’s European Society of Medical Oncology (ESMO) 2020 Virtual Annual Meeting, Dr. Maha Hussain presented results of the PROSPER trial, stratified according to prostate-specific antigen (PSA) response.

To summarize the design of the PROSPER trial, men with nmCRPC, a prostate-specific antigen (PSA) doubling time ≤10 months, and an absolute PSA ≥2 ng/mL were randomized to enzalutamide 160 mg PO daily or placebo in addition to standard ADT with the primary endpoint of metastasis-free survival.

As a result of 2:1 randomization, 933 men were randomized to enzalutamide. By week 17, 79% of men randomized to enzalutamide had PDA declines >50% compared to baseline with 23% having an undetectable PSA (< 0.2 ng/mL). In comparison, PSA declines of >50% were observed in 5% of men randomized to placebo and none achieved an undetectable PSA.


The authors then focused their analysis on men receiving enzalutamide. In this group, multivariable modeling demonstrating that PSA decline from baseline was significantly associated with metastasis-free survival.


Presented by: Maha Hussain, MD, FACP, FASCO, is the Genevieve Teuton Professor of Medicine in the Division of Hematology-Oncology, Department of Medicine, and the Deputy Director at the Robert H. Lurie Comprehensive Cancer Center of the Northwestern University Feinberg School of Medicine, Chicago, IL. 

Written by: Christopher J.D. Wallis, Urologic Oncology Fellow, Vanderbilt University Medical Center Contact: @WallisCJD at the European Society for Medical Oncology Virtual Congress, ESMO Virtual Congress 2020 #ESMO20, 18 Sept - 21 Sept 2020

Related Content:
Final Overall Survival Analysis of the PROSPER Trial in Nonmetastatic Castration-Resistant Prostate Cancer - Karim Fizazi
The PROSPER Trial: Chemotherapy-Related Endpoints in Patients with nmCRPC - Neal Shore
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