Study of JANX014 in Subjects With Metastatic Castration-Resistant Prostate Cancer

August 6, 2026 updated by: Janux Therapeutics

A Phase 1 Open-Label, Multicenter Study of JANX014 in Participants With Prostate Cancer

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 JANX014 in adults with metastatic castration-resistant prostate cancer (mCRPC).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

43

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Missouri
      • St Louis, Missouri, United States, 63108
        • Recruiting
        • Washington University School of Medicine
    • South Carolina
      • Greenville, South Carolina, United States, 29605
        • Recruiting
        • Prisma Health Cancer Institute
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • SCRI Oncology Partners
    • Texas
      • Dallas, Texas, United States, 75230
        • Recruiting
        • SCRI at Mary Crowley

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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: 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 Dose Expansion Part: Have received ≤ 2 anti-androgen therapies in either the HSPC or CRPC setting and no more than 1 prior taxane regimen in the HSPC 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 any CAR-T cell therapy, approved or investigational T-cell engager therapy, and prior receipt of radioligand therapy
  • Clinically significant cardiovascular disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Dose Escalation
JANX014 will be administered at increasing dose levels per cohort to determine the maximum tolerated dose.
Biological: JANX014
JANX014 will be administered via IV dosing
Experimental: Dose Expansion
Participants will be dosed at levels previously declared tolerable.
Biological: JANX014
JANX014 will be administered via IV dosing

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Incidence of Dose Limiting Toxicities (DLTs)
Time Frame: 2 years
2 years
Incidence of adverse events (AE) and Serious Adverse Events (SAE)
Time Frame: 2 years
2 years

Secondary Outcome Measures

Outcome Measure
Time Frame
Duration of Response
Time Frame: up to 2 years
up to 2 years
Overall Response Rate
Time Frame: up to 2 years
up to 2 years
Area under the curve from time 0 to t of JANX014 (AUC0-t)
Time Frame: up to 2 years
up to 2 years
Maximum observed concentration of JANX014 (Cmax)
Time Frame: up to 2 years
up to 2 years
Number of participants who develop anti-drug antibodies against JANX014
Time Frame: up to 2 years
up to 2 years
Prostate Specific Antigen (PSA) response
Time Frame: up to 2 years
up to 2 years
Radiographic Progression Free Survival (rPFS)
Time Frame: up to 2 years
up to 2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Janux Therapeutics

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 15, 2026

Primary Completion (Estimated)

May 1, 2028

Study Completion (Estimated)

March 1, 2029

Study Registration Dates

First Submitted

April 16, 2026

First Submitted That Met QC Criteria

April 16, 2026

First Posted (Actual)

April 22, 2026

Study Record Updates

Last Update Posted (Actual)

August 10, 2026

Last Update Submitted That Met QC Criteria

August 6, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PRCA-014-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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