This Study Will Explore Whether a Combination of the Investigational Drug Mevrometostat (PF-06821497) and Enzalutamide Will Work Better Than Taking Enzalutamide Alone in Participants With mCSPC Who Are ARPI naïve.

Eligibility: for males ages 18 years and up (full criteria)
Location: at Alhambra, California and other locations
Dates: study started September 2025
study ends around December 2034

Description

Summary

This study will explore whether a combination of the investigational drug mevrometostat (PF-06821497) and enzalutamide will work better than taking enzalutamide alone in participants with mCSPC who are ARPI naïve and have not yet received chemotherapy in the mCSPC setting.

Official Title

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Mevrometostat (PF-06821497) With Enzalutamide in Metastatic Castration-Sensitive Prostate Cancer (MEVPRO-3)

Details

This is a global, multicenter, randomized, double-blind, placebo-controlled Phase 3 study evaluating mevrometostat in combination with enzalutamide versus placebo in combination with enzalutamide in participants with mCSPC who have not received systemic anticancer treatments with the exception of androgen-deprivation therapy (ADT) and first-generation antiandrogen agents. Prior therapy with up to 3 months of ADT (chemical or surgical) is allowed, with no radiographic evidence of disease progression or rising PSA levels prior to Day 1.

This study consists of a Screening Phase, Randomization, Treatment Phase, Safety Follow-up, and Long-Term Follow-up. Participants will be randomized on a 1:1 basis to receive (Arm A) mevrometostat (PF-06821497) in combination with enzalutamide, or (Arm B) placebo in combination with enzalutamide.

Keywords

Metastatic Castration Sensitive Prostate Cancer (mCSPC), Hormone Sensitive Prostate Cancer, Prostate Cancer, Cancer of the Prostate, Mevrometostat, Metastatic castration sensitive prostate cancer, PF-06821497, EZH2, enhancer of zeste homologue-2, enzalutamide, mCSPC, HSPC, castrate sensitive prostate cancer, prostatecancer-study.com, Phase 3, efficacy, safety, pharmacokinetics, pharmacodynamics, Prostatic Neoplasms, PF06821497

Eligibility

You can join if…

Open to males ages 18 years and up

Male participants aged ≥18 years (or the minimum age of consent in accordance with local regulations) at screening.
Histologically or cytologically confirmed adenocarcinoma of the prostate without small cell features.
Metastatic prostate cancer documented by positive bone scan (for bone disease) or metastatic lesion(s) on CT or MRI (for soft tissue/visceral disease).
Resolution of acute effects of any prior therapy to either baseline severity or CTCAE Grade ≤1 (except for AEs which do not constitute a safety risk in the investigator's judgement).
Participants must have ECOG PS 0 or 1.

You CAN'T join if...

Any medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
Clinically significant cardiovascular disease.
Known or suspected brain metastasis or active leptomeningeal disease.
Participants must be treatment naïve at the mCSPC stage, eg, participants cannot have received any cytotoxic chemotherapy with the following exceptions: Treatment with first-generation antiandrogen (ADT) agents is allowed for mCSPC.
Previous administration with an investigational product (drug or vaccine) within 30 days.
Use of 5-alpha reductase inhibitors is prohibited within 28 days of randomization.
Prior surgery from which the participant has not fully recovered at least 28 days prior to randomization
Current use or anticipated need for drugs that are known strong CYP3A4/5 inhibitors and inducers (with exception of enzalutamide as part of this study).
Inadequate organ function.

Locations

UCLA Hematology/Oncology - Alhambra accepting new patients
Alhambra California 91801 United States
UCLA Hematology/Oncology - Beverly Hills accepting new patients
Beverly Hills California 90212 United States
UCLA Hematology/Oncology - Burbank accepting new patients
Burbank California 91505 United States
UCLA Hematology/Oncology - Encino accepting new patients
Encino California 91436 United States
UCLA Hematology/Oncology - Irvine accepting new patients
Irvine California 92604 United States
UCLA Hematology/Oncology - Laguna Hills accepting new patients
Laguna Hills California 92653 United States
Ronald Reagan UCLA Medical Center - Drug Information Center accepting new patients
Los Angeles California 90095 United States
UCLA Department of Medicine - Hematology/Oncology accepting new patients
Los Angeles California 90095 United States
UCLA Hematology/Oncology accepting new patients
Los Angeles California 90095 United States
UCLA Hematology/Oncology - Marina del Rey accepting new patients
Marina del Rey California 90292 United States
UCLA Hematology/Oncology - Pasadena accepting new patients
Pasadena California 91105 United States
UCLA Hematology/Oncology - Porter Ranch accepting new patients
Porter Ranch California 91326 United States
UCLA Hematology/Oncology- Santa Monica accepting new patients
Santa Monica California 90404 United States
UCLA Hematology/Oncology - Torrance accepting new patients
Torrance California 90505 United States
UCLA Hematology/Oncology - Santa Clarita accepting new patients
Valencia California 91355 United States
UCLA Hematology/Oncology - Ventura accepting new patients
Ventura California 93003 United States
UCLA Hematology/Oncology - Westlake accepting new patients
Westlake Village California 91361 United States

Details

Status: accepting new patients
Start Date: September 2025
Completion Date: December 2034 (estimated)
Sponsor: Pfizer
Links: Sign up for this study
ID: NCT07028853
Phase: Phase 3 Prostate Cancer Research Study
Study Type: Interventional
Participants: Expecting 1000 study participants
Last Updated: March 26, 2026

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