Recruiting

Phase 1

JANX007Study of JANX007 in Subjects With Metastatic Castration-Resistant Prostate Cancer (ENGAGER-PSMA-01)

Sponsor:

Janux Therapeutics

Code:

NCT05519449

Conditions

Prostate Cancer

Metastatic Castration-resistant Prostate Cancer

Castration Resistant Prostatic Cancer

Eligibility Criteria

Sex: Male

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

JANX007

Darolutamide

Study Details

Brief summary:

This study is a first-in-human, Phase 1, open-label, multicenter study to assess the safety, tolerability, pharmacokinetic (PK), pharmacodynamic (PD), and the preliminary efficacy of JANX007 in adults with metastatic castration-resistant prostate cancer (mCRPC).

Conditions

Prostate Cancer

Metastatic Castration-resistant Prostate Cancer

Castration Resistant Prostatic Cancer

Study ID

NCT05519449

Start date

Sep 15, 2022

Status verified date

Aug, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Jul, 2027

Anticipated

Eligibility Criteria

Sex: Male

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

Male ≥18 years of age at the time of signing informed consent
Histologically or cytologically confirmed adenocarcinoma of the prostate
For Dose Escalation and Backfill: Having mCRPC that progressed after at least one novel anti-androgen therapy and at least one taxane containing regimen. Participants who have actively refused a taxane containing regimen or are medically unsuitable to receive taxane are eligible
Adequate organ function
For Monotherapy Expansion Part a: Have received ≤ 2 anti-androgen therapies in either the HSPC or CRPC setting and no more than 1 prior taxane regimen in the HSPC or CRPC setting. Participants who have actively refused a taxane regimen or are medically unsuitable to receive taxane are eligible.
For Monotherapy Expansion Part b: Have received ≤ 2 anti-androgen therapies in either the HSPC or CRPC settings
For Monotherapy Expansion Part d: Have received ≤ 1 anti-androgen therapy and a poly(ADP-ribose) polymerase (PARP) inhibitor for mCRPC and have progressed following treatment with the PARP inhibitor
For Combination Expansion: Have received ≤ 1 anti-androgen therapy other than darolutamide in the HSPC setting and ≤ 1 taxane in the mCRPC setting. Participants who have actively refused a taxane regimen or are medically unsuitable to receive taxane are eligible.

Exclusion Criteria:

Prior solid organ transplant
Prior treatment with PSMA-targeted CAR-T cell therapy or PSMA-CD3, PSMA-CD28 or other CD3 T-cell engaging bispecific antibodies or radioligand therapy
Clinically significant cardiovascular disease
For Monotherapy Expansion Part a: Prior receipt of any treatment other than an ARPI or taxane in the mCRPC setting
For Monotherapy Expansion Part b: Prior receipt of any treatment other than an anti-androgen therapy or prior receipt of a taxane containing regimen or more than 1 prior line of therapy for mCRPC
For Monotherapy Part d: More than 1 prior line of therapy for mCRPC or prior receipt of any treatment other than an anti-androgen therapy and PARP inhibitor for mCRPC or prior receipt of a taxane in the mCRPC setting
For Combination expansion: More than 1 prior line of therapy for mCRPC or prior receipt of any treatment other than a taxane for mCRPC or prior receipt of Darolutamide or prior receipt of a taxane for HSPC
Active clinically significant infection (bacterial, viral, fungal, mycobacteria or other)
Any medical condition or clinical laboratory abnormality likely to interfere with assessment of safety or efficacy of study treatment

Study Design

Enrollment

272 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Dose Escalation

IV dosing during 21- or 28-day cycles. Dosage per cohort will increase to determine the maximum tolerable dose.

experimental: Backfill Expansion

IV dosing during 21- or 28-day cycles. Subjects will be dosed at levels previously declared tolerable.

experimental: Monotherapy Expansion Parts A - D

IV dosing during 21- or 28-day cycles. Subjects will be dosed at preliminary recommended phase 2 dose (RP2D).

experimental: Combination Expansion

IV dosing during 21- or 28-day cycles. Subjects will be dosed at preliminary recommended phase 2 dose

Interventions

JANX007

JANX007 is dosed via IV in a 21- or 28-day cycle.

Darolutamide

Darolutamide is dosed via oral tablets

Primary outcome measure

Incidence of Dose Limiting Toxicities (DLT) [ Time Frame: 3 years ]
Incidence of Adverse Events (AE) and Serious Adverse Events (SAE) [ Time Frame: 3 years ]

Central Contacts and Locations

Central contacts

Janux Therapeutics

858-206-8471 psma-007-001_ct.gov@januxrx.com

Locations

University of Alabama at Birmingham Hospital

Recruiting

Birmingham, Alabama, United States, 35249

Mayo Clinic

Recruiting

Phoenix, Arizona, United States, 85054

USC Norris Comprehensive Cancer Center

Recruiting

Los Angeles, California, United States, 90033

UCLA Department of Medicine

Recruiting

Los Angeles, California, United States, 90095

Hoag Memorial Hospital Presbyterian

Recruiting

Newport Beach, California, United States, 92663

University of California Davis Comprehensive Cancer Center

Recruiting

Sacramento, California, United States, 95817

UCSF Helen Diller Family Comprehensive Cancer Center

Recruiting

San Francisco, California, United States, 94158

Contacts

HDFCCC.CIP@ucsf.edu

Yale New Haven Hospital

Recruiting

New Haven, Connecticut, United States, 06510

Mayo Clinic

Recruiting

Jacksonville, Florida, United States, 32224

University of Chicago Medical Center

Recruiting

Chicago, Illinois, United States, 60637

University of Maryland Greenebaum Comprehensive Cancer Center

Recruiting

Baltimore, Maryland, United States, 21201

University of Minnesota Medical Center

Recruiting

Minneapolis, Minnesota, United States, 55455

Mayo Clinic

Recruiting

Rochester, Minnesota, United States, 55905

Washington University School of Medicine

Recruiting

St Louis, Missouri, United States, 63110

Northwell Health R.J. Zuckerberg Cancer Hospital

Recruiting

Lake Success, New York, United States, 11042

NYU Langone Health Long Island

Recruiting

Mineola, New York, United States, 11501

NYU Langone Health

Recruiting

New York, New York, United States, 10016

Memorial Sloan Kettering Cancer Center

Recruiting

New York, New York, United States, 10065

Weill Cornell Medicine

Recruiting

New York, New York, United States, 10065

Montefiore Medical Center

Recruiting

The Bronx, New York, United States, 10461

University of Cincinnati Medical Center

Recruiting

Cincinnati, Ohio, United States, 45267

The Ohio State University

Recruiting

Columbus, Ohio, United States, 43221

Penn State Milton S. Hershey Medical Center

Recruiting

Hershey, Pennsylvania, United States, 17033

Thomas Jefferson University Honickman Center

Recruiting

Philadelphia, Pennsylvania, United States, 19107

UPMC Hillman Cancer Center

Recruiting

Pittsburgh, Pennsylvania, United States, 15232

Rhode Island Hospital

Recruiting

Providence, Rhode Island, United States, 02903

Medical University of South Carolina

Recruiting

Charleston, South Carolina, United States, 29425

Sarah Cannon Research

Recruiting

Nashville, Tennessee, United States, 37203

Mary Crowley Cancer Research

Recruiting

Dallas, Texas, United States, 75230

University of Texas Southwestern Medical Center

Recruiting

Dallas, Texas, United States, 75390

Houston Methodist Hospital

Recruiting

Houston, Texas, United States, 77030

University of Wisconsin Carbone Cancer Center

Recruiting

Madison, Wisconsin, United States, 53792

Froedtert Hospital and the Medical College of Wisconsin

Recruiting

Milwaukee, Wisconsin, United States, 53226

More Information

Sponsor

Janux Therapeutics

Last update posted

Aug 13, 2026

Last verified

Aug, 2026

Keywords

Prostate Cancer
Castration-resistant prostate cancer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Janux Therapeutics on 2026-08-13.