Purpose

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.

Conditions

Eligibility

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

Inclusion Criteria

  • 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

Exclusion Criteria

  • • 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

Study Design

Phase
Phase 2
Study Type
Interventional
Allocation
N/A
Intervention Model
Single Group Assignment
Intervention Model Description
Single group assignment, all participants will receive MRT-2359 in combination with apalutamide.
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
MRT-2359 + Apalutamide
Participants with castration-resistant prostate cancer will receive MRT-2359 in combination with apalutamide.
  • Drug: Oral MRT-2359
    Orally administered tablets of MRT-2359
  • Drug: Apalutamide
    Orally administered apalutamide

Recruiting Locations

START Los Angeles
Los Angeles, California 90025

START New Jersey
East Brunswick, New Jersey 08816

START Mountain Region
West Valley City, Utah 84119

More Details

Status
Recruiting
Sponsor
Monte Rosa Therapeutics, Inc

Study Contact

Monte Rosa Therapeutics Sponsor
617-865-4792
MRT-2359-002StudyTeam@monterosatx.com

Detailed Description

This Phase 2, open-label, multicenter study is designed to assess the efficacy, safety, tolerability, pharmacokinetic (PK), pharmacodynamic (PD), and clinical activity of MRT-2359 in combination with apalutamide in patients with castration-resistant prostate cancer. The primary aim of the study is to assess the PSA response rate of MRT-2359 in combination with apalutamide as determined by PCWG4 criteria. Secondary aims include further evaluation of safety and tolerability, additional measures of anti-tumor activity, and characterization of the PK profile of MRT-2359 in combination with apalutamide.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.