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.

Purpose

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.

Conditions

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

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
Male
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 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.

Exclusion Criteria

  • 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. - 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.

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Treatment
Masking
Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Masking Description
This is a double-blind study. Participants will receive mevrometostat or matching placebo in a blinded fashion. Participants, investigators and site staff, and sponsor staff will be aware that participants in both study arms are receiving enzalutamide. Enzalutamide will be provided in an open-label manner to participants in each treatment arm. Participants and their caregivers will be blinded to their assigned study intervention. Investigators and other site staff will be blinded to participants' assigned study intervention Sponsor staff will be blinded to participants' assigned study intervention, except for sponsor staff involved in the assignment or distribution of study intervention.

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Arm A 		Participants will receive mevrometostat/PF-06821497 (875 mg) BID (twice daily) + enzalutamide 160 mg QD (once daily)
  • Drug: Mevrometostat
    Oral continuous
    Other names:
    • PF-06821497
  • Drug: Enzalutamide
    Oral continuous
    Other names:
    • Xtandi
Active Comparator
Arm B 		Participants will receive Placebo BID (twice daily) + enzalutamide 160 mg QD (once daily)
  • Drug: Placebo
    Oral continuous
  • Drug: Enzalutamide
    Oral continuous
    Other names:
    • Xtandi

Recruiting Locations

Ironwood Cancer & Research Centers
Chandler 5289282, Arizona 5551752 85224

Ironwood Cancer & Research Centers
Gilbert 5295903, Arizona 5551752 85297

Ironwood Cancer & Research Centers
Glendale 5295985, Arizona 5551752 85306

Ironwood Cancer & Research Centers
Goodyear 5296266, Arizona 5551752 85395

Ironwood Cancer & Research Centers
Mesa 5304391, Arizona 5551752 85202

Ironwood Cancer & Research Centers
Mesa 5304391, Arizona 5551752 85206

Ironwood Cancer & Research Centers
Phoenix 5308655, Arizona 5551752 85028

Ironwood Cancer & Research Centers
Scottsdale 5313457, Arizona 5551752 85260

Highlands Oncology Group, PA
Fayetteville 4110486, Arkansas 4099753 72703

Highlands Oncology Group, PA
Rogers 4128894, Arkansas 4099753 72758

Highlands Oncology Group, PA
Springdale 4132093, Arkansas 4099753 72762

The Centers for Advanced Urology, LLP d/b/a Keystone Urology Specialists
Lancaster 5197079, Pennsylvania 6254927 17604

Grand Strand Medical Center
Myrtle Beach 4588718, South Carolina 4597040 295724607

Carolina Urologic Research Center, LLC
Myrtle Beach 4588718, South Carolina 4597040 29572

Parkway Surgery Center
Myrtle Beach 4588718, South Carolina 4597040 29572

Urology Associates, P.C.
Nashville 4644585, Tennessee 4662168 37209

US Oncology Investigational Product Center (IPC)
Irving 4700168, Texas 4736286 75063

Huntsman Cancer Institute
Salt Lake City 5780993, Utah 5549030 84112

Blue Ridge Cancer Care
Blacksburg 4747845, Virginia 6254928 24060

Blue Ridge Cancer Care
Low Moor 4770856, Virginia 6254928 24457

Blue Ridge Cancer Care
Roanoke 4782167, Virginia 6254928 24014

Blue Ridge Cancer Care
Salem 4784112, Virginia 6254928 24153

Blue Ridge Cancer Care
Wytheville 4794837, Virginia 6254928 24382

Northwest Medical Specialties, PLLC
Bonney Lake 5787776, Washington 5815135 98391

Northwest Medical Specialties, PLLC
Federal Way 5794245, Washington 5815135 98003

Northwest Medical Specialties, PLLC
Gig Harbor 5795440, Washington 5815135 98332

Northwest Medical Specialties, PLLC
Puyallup 5807575, Washington 5815135 98373

Northwest Medical Specialties, PLLC
Tacoma 5812944, Washington 5815135 98405

More Details

Status
Recruiting
Sponsor
Pfizer

Study Contact

Pfizer CT.gov Call Center
1-800-718-1021
ClinicalTrials.gov_Inquiries@pfizer.com

Detailed Description

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.