NCT07745361

Brief Summary

This Phase 2, open-label, multicenter study is conducted in patients with castration-resistant prostate cancer. Patients in this study receive MRT-2359, an investigational oral medicine, in combination with apalutamide, an oral medicine used to treat prostate cancer. The main purpose of the study is to assess whether this treatment combination can lower prostate-specific antigen (PSA) The study will also evaluate the safety and tolerability of the treatment combination and assess additional measures of anti-tumor activity.

Trial Health

77
On Track

Trial Health Score

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

Enrollment
25

participants targeted

Target at below P25 for phase_2

Timeline
20mo left

Started Aug 2026

Geographic Reach
1 country

14 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

Study Progress1%
Aug 2026Apr 2028

First Submitted

Initial submission to the registry

July 29, 2026

Completed
3 days until next milestone

Study Start

First participant enrolled

August 1, 2026

Completed
3 days until next milestone

First Posted

Study publicly available on registry

August 4, 2026

Completed
1.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 1, 2027

Expected
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

April 1, 2028

Last Updated

August 4, 2026

Status Verified

August 1, 2026

Enrollment Period

1.2 years

First QC Date

July 29, 2026

Last Update Submit

August 3, 2026

Conditions

Castration-Resistant Prostate CancerProstate CancerCastration-Resistant Prostate Cancer (CRPC)Prostate Cancer (Adenocarcinoma)

Keywords

MRT-2359apalutamidecastration-resistant prostate cancerCRPCandrogen receptor mutationAR mutationPSA responseandrogen receptor inhibitormolecular glue degraderGSPT1

Outcome Measures

Primary Outcomes (1)

  • Assess the efficacy of MRT-2359 combined with apalutamide

    Assess the efficacy of MRT-2359 combined with apalutamide using the PSA response rate as determined by PCWG4 criteria in participants with measurable and/or evaluable disease

    14 months

Secondary Outcomes (11)

  • Further evaluation of the safety and tolerability of MRT-2359 administered orally in combination with apalutamide

    20 months

  • To assess additional measures of the efficacy of MRT-2359 in combination with apalutamide

    20 months

  • To assess additional measures of the efficacy of MRT-2359 in combination with apalutamide

    20 months

  • To assess additional measures of the efficacy of MRT-2359 in combination with apalutamide

    20 months

  • To assess additional measures of the efficacy of MRT-2359 in combination with apalutamide

    20 months

  • +6 more secondary outcomes

Study Arms (1)

MRT-2359 + Apalutamide

EXPERIMENTAL

Participants with castration-resistant prostate cancer will receive MRT-2359 in combination with apalutamide.

Drug: Oral MRT-2359Drug: Apalutamide

Interventions

ApalutamideDRUG

Orally administered apalutamide

MRT-2359 + Apalutamide
Oral MRT-2359DRUG

Orally administered tablets of MRT-2359

MRT-2359 + Apalutamide

Eligibility Criteria

Age18 Years+
Sexmale
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Age \> 18 years
  • A predicted life expectancy of ≥ 3 months and an ECOG performance status ≤ 1
  • Have histologically or cytologically confirmed castration-resistant adenocarcinoma of the prostate without small cell histology and with androgen receptor (AR) mutations
  • Have not had prior treatment with more than 1 prior taxane-based chemotherapy regimen for castration-resistant prostate cancer
  • Have no prior treatment with an AR degrader, opevesostat, or similar therapy
  • Has ongoing (chemical or surgical) androgen deprivation with serum testosterone \< 50 ng/dL (\< 1.7 nM)
  • Has received prior treatment with poly(ADP-ribose) polymerase (PARP) inhibitor, if appropriate, or deemed ineligible to receive treatment by the Investigator, or has refused PARP inhibitor treatment
  • Has received prior treatment with at least 1 line of ARPi
  • Have disease measurable per Prostate Cancer Working Group 4 (PCWG4) criteria, with or without measurable disease by RECIST 1.1
  • Be able to provide a tumor biopsy for biomarker analysis during the Screening period
  • Have adequate organ function

You may not qualify if:

  • Have received prior chemotherapy, definitive radiation, or biological cancer therapy within 21 days before the first dose of study treatment or have any AEs that have failed to recover to baseline
  • Have received prior therapy with a GSPT1 degrader that was discontinued due to an AE
  • Have received prior auto-HCT and have not fully recovered from effects of the last transplant
  • Have received allogeneic hematopoietic stem cell transplantation within past 6 months and/or have symptoms of graft-versus-host disease
  • Current use of chronic systemic steroid therapy in excess of replacement doses
  • Have clinically active central nervous system involvement and/or carcinomatous meningitis
  • Have a confirmed history of (noninfectious) pneumonitis that required steroids
  • Clinically significant cardiac disease

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (14)

START Los Angeles

Los Angeles, California, 90025, United States

RECRUITING

Hoag Memorial Hospital Presbyterian

Newport Beach, California, 92663, United States

NOT YET RECRUITING

Rocky Mountain Cancer Center

Colorado Springs, Colorado, 80907, United States

NOT YET RECRUITING

Kansas University Cancer Center

Kansas City, Kansas, 66160, United States

NOT YET RECRUITING

University of Maryland Greenebaum Cancer Center

Baltimore, Maryland, 21201, United States

NOT YET RECRUITING

Henry Ford

Novi, Michigan, 48377, United States

NOT YET RECRUITING

XCancer Omaha

Omaha, Nebraska, 68130, United States

NOT YET RECRUITING

START New Jersey

East Brunswick, New Jersey, 08816, United States

RECRUITING

Levine Cancer Institute

Charlotte, North Carolina, 28204, United States

NOT YET RECRUITING

Lancaster Urology

Lancaster, Pennsylvania, 17601, United States

NOT YET RECRUITING

Sarah Cannon Research Institute

Nashville, Tennessee, 37203, United States

NOT YET RECRUITING

START Mountain Region

West Valley City, Utah, 84119, United States

RECRUITING

Virginia Cancer Specialists

Fairfax, Virginia, 22031, United States

NOT YET RECRUITING

University of Washington Medical Center

Seattle, Washington, 98195, United States

NOT YET RECRUITING

MeSH Terms

Conditions

Prostatic NeoplasmsAdenocarcinoma

Interventions

apalutamide

Condition Hierarchy (Ancestors)

Genital Neoplasms, MaleUrogenital NeoplasmsNeoplasms by SiteNeoplasmsGenital Diseases, MaleGenital DiseasesUrogenital DiseasesProstatic DiseasesMale Urogenital DiseasesCarcinomaNeoplasms, Glandular and EpithelialNeoplasms by Histologic Type

Central Study Contacts

Monte Rosa Therapeutics Sponsor

CONTACT

617-865-4792MRT-2359-002StudyTeam@monterosatx.com

Study Design

Study Type
interventional
Phase
phase 2
Allocation
NA
Masking
NONE
Purpose
TREATMENT
Intervention Model
SINGLE GROUP
Model Details: Single group assignment, all participants will receive MRT-2359 in combination with apalutamide.
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

July 29, 2026

First Posted

August 4, 2026

Study Start

August 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

April 1, 2028

Last Updated

August 4, 2026

Record last verified: 2026-08

Data Sharing

IPD Sharing
Will not share

Locations

US(14)