NCT07028853|RecruitingPhase 3DMCFDA Drug

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.

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

Pfizer ClinicalTrials.gov

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3 other identifiers

C2321008MEVPRO-32024-519369-24-00

Study Type

interventional

Target

1,000

Locations

26 countries

Sites

300

Timeline

RegisteredJun 2025

StartedSep 2025

CompletionDec 2034

Brief 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.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Strong global presence with extensive site network

Enrollment

1,000

participants targeted

Target at P75+ for phase_3

Timeline

105mo left

Started Sep 2025

Longer than P75 for phase_3

Geographic Reach

26 countries

300 active sites

Status

recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

9.2 years study duration

Study Progress7%

Sep 2025Dec 2034

First Submitted

Initial submission to the registry

April 15, 2025

Completed

2 months until next milestone

First Posted

Study publicly available on registry

June 19, 2025

Completed

3 months until next milestone

Study Start

First participant enrolled

September 28, 2025

Completed

3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 12, 2028

Expected

6.2 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 8, 2034

Last Updated

May 5, 2026

Status Verified

May 1, 2026

Enrollment Period

3 years

First QC Date

April 15, 2025

Last Update Submit

May 4, 2026

Conditions

Hormone Sensitive Prostate Cancer Metastatic Castration Sensitive Prostate Cancer (mCSPC)Prostate Cancer Cancer of the Prostate

Keywords

Hormone Sensitive Prostate CancerMevrometostatMetastatic castration sensitive prostate cancerPF-06821497EZH2enhancer of zeste homologue-2enzalutamidemCSPCHSPCProstate cancercastrate sensitive prostate cancerprostatecancer-study.comPhase 3efficacysafetypharmacokineticspharmacodynamics

Outcome Measures

Primary Outcomes (1)

Radiographic Progression Free Survival (rPFS)
rPFS is defined as the time from randomization until PD based on BICR assessment per RECIST v1.1 (soft tissue disease) and PCWG3 (bone disease), or death due to any cause, whichever occurs first.
Randomization up to approximately 4 years

Secondary Outcomes (17)

Overall survival (OS)
Randomization up to approximately 9 years
Objective response in measurable soft tissue disease
Randomization up to approximately 4 years
Duration of Response (DoR) in measurable soft tissue disease
Randomization up to approximately 4 years
Prostate Specific Antigen Response
Randomization up to approximately 4 years
Time to prostate specific antigen (PSA) progression
Randomization up to approximately 4 years
+12 more secondary outcomes

Study Arms (2)

Arm A

EXPERIMENTAL

Participants will receive mevrometostat/PF-06821497 (875 mg) BID (twice daily) + enzalutamide 160 mg QD (once daily)

Drug: MevrometostatDrug: Enzalutamide

Arm B

ACTIVE COMPARATOR

Participants will receive Placebo BID (twice daily) + enzalutamide 160 mg QD (once daily)

Drug: PlaceboDrug: Enzalutamide

Interventions

MevrometostatDRUG

Oral continuous

Also known as: PF-06821497

Arm A

PlaceboDRUG

Oral continuous

Arm B

EnzalutamideDRUG

Oral continuous

Also known as: Xtandi

Arm AArm B

Eligibility Criteria

Age18 Years+

Sexmale(Gender-based eligibility)

Gender Eligibility DetailsMale participants aged ≥18 years (or the minimum age of consent in accordance with local regulations) at screening with a diagnosis of mCSPC.

Healthy VolunteersNo

Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

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 may not qualify 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Pfizerlead

Study Sites (300)

Clearview Cancer Institute (Crestwood)

Huntsville, Alabama, 35801, United States

NOT YET RECRUITING

Clearview Cancer Institute

Huntsville, Alabama, 35805, United States

NOT YET RECRUITING