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Metastatic Castration-Resistant Prostate AdenocarcinomaPhase 1NCT07803653

IL-18 Armored STEAP1 CAR T Cells for the Treatment of Metastatic Castration Resistant Prostate Cancer

A Phase 1 study testing FH-STEAP1 IL-18 CAR T cells, Antiandrogen Therapy and Biospecimen Collection in people with Metastatic Castration-Resistant Prostate Adenocarcinoma and Stage IVB Prostate Cancer AJCC v8, run by Fred Hutchinson Cancer Center at 1 site in United States.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
Search all trials

Trial summary

This phase I trial tests the safety, side effects, best dose and how well giving IL-18 armored STEAP1 CAR T cells after lymphodepleting chemotherapy (with cyclophosphamide and fludarabine) works for the treatment of castration resistant prostate cancer that has spread from where it first started (primary site) to… Read more about this study

Who is it for?
Ages 18 years and older, men only
What is being tested?
FH-STEAP1 IL-18 CAR T cells, Antiandrogen Therapy and Biospecimen Collection
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteUnited States
Study dates
31 Oct 2026to 31 Oct 2044
Phase
Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Men only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Documented, histologically confirmed adenocarcinoma of the prostate
  • Measurable disease by RECIST 1.1 criteria or bone only metastases with measurable PSA (≥ 1ng/mL)
  • Must have mCRPC with progressive disease (PD), stable disease (SD), lack of clinical benefit or intolerance to ≥ 1 line of systemic therapy, after becoming castration resistant
  • Have received the following for metastatic prostate cancer:
  • At least two lines of Food and Drug Administration (FDA)-approved therapies with at least one being a second-generation androgen receptor signaling inhibitor.
  • Targeted therapies for which they are eligible in the metastatic setting unless the patient has contraindications to receiving those medications, the agents are not available to the patient or the patient declines to receive these drugs due to personal preference
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  • Castrate levels of testosterone (< 50 ng/dL) with or without the use of androgen deprivation therapy
  • 18 years or older at the time of enrollment
  • Capable of understanding and providing written informed consent
  • Fertile male participants and their female partners must be willing to use an effective contraceptive method before, during, and for at least 4 months after the FH-STEAP1 IL-18 CAR T cell infusion
  • Participants will be permitted to receive radiation therapy for palliative purposes throughout the study period, except during the 2-week period prior to undergoing leukapheresis
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
  • Serum creatinine ≤ 1.5 x upper limit of normal (ULN) or estimated creatinine clearance > 50 mL/min as calculated using the Cockcroft-Gault formula and not dialysis dependent
  • Total bilirubin ≤ 1.5 x ULN. Participants with suspected Gilbert syndrome may be included if total bilirubin (bili) > 3 mg/dL but no other evidence of hepatic dysfunction
  • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) < 5 x ULN
  • ≤ grade 1 dyspnea and oxygen saturation (SaO2) ≥ 92% on ambient air. If pulmonary function tests (PFTs) are performed based on the clinical judgement of the treating physician, participants with forced expiratory volume at 1 second (FEVI) ≥ 50% of predicted and carbon monoxide diffusing capability (DLCO) (adjusted for lung volume) of ≥ 40% of predicted will be eligible
  • All participants ≥ 60 years of age are required to have left ventricular ejection fraction (LVEF) evaluation performed within 1 year prior to lymphodepletion chemotherapy. LVEF may be established with an echocardiogram or MUGA scan, and left ejection fraction must be ≥ 45%
  • Absolute neutrophil count (ANC) > 1500 cells/ mm^3
  • Hemoglobin ≥ 9g g/dL
  • Platelets > 100,000 per mm^3

Who cannot join

  • Expecting to conceive or father children for the duration of the trial through 4 months after T cell infusion
  • Patients that require immediate therapy due to mass effect or spinal cord compression
  • Active autoimmune disease: Participants with active autoimmune disease requiring chronic immunosuppressive therapy are excluded. Case by case exemptions are possible with approval by principal investigator (PI)
  • Corticosteroid therapy at a dose equivalent of > 10 mg of prednisone per day (or equivalent). Pulsed corticosteroid use for disease control is acceptable
  • Concurrent use of other investigational anti-cancer agents except for androgen deprivation therapy
  • Uncontrolled concurrent illness: Participants may not have uncontrolled respiratory, endocrine, renal, gastrointestinal, genitourinary or systemic infection. There are exceptions to this criterion:
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  • HIV positive participants on highly active antiretroviral therapy (HAART) with a CD4 count > 500 cells/mm^3 are considered controlled, as are individuals with a history of hepatitis C who have successfully completed antiviral therapy with an undetectable viral load, and those with hepatitis B who have hepatitis well controlled on medication;
  • Patients who have recent history of cerebrovascular accident, transient ischemic attack should be cleared by the neurology service before enrolling this study
  • Patients who have recent history of coronary artery disease or cardiac arrhythmia should be cleared by the cardiology service before enrolling this study. Case by case exemptions are possible with approval by PI
  • Participants with brain metastasis
  • Active treatment for prior immune related adverse event to any immunotherapy: Participants receiving ongoing treatment for prior serious immune-related adverse events are excluded, with exception of hormone supplementation or corticosteroid therapy at equivalent of > 10 mg prednisone (or equivalent) per day, unless otherwise approved by PI
  • Patients with a second malignancy in addition to their prostate cancer are not eligible if the second malignancy has required systemic treatment within the past 4 years or is not in complete remission. There are exceptions to this criterion: successfully treated non-metastatic basal cell and squamous cell skin carcinoma
  • Other medical, social, or psychiatric factor that interferes with medical appropriateness and/or ability to comply with study, as determined by the PI
  • Known allergic reactions to any of the components of study treatments
  • Participants who do not have a reasonable standard-of-care bridging therapy option available, as determined by the treating medical oncologist, to maintain disease control should clinically significant disease progression or worsening symptoms occur during the screening and T-cell manufacturing period

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Fred Hutch Intake contact

206-606-1024

hutchdoc@fredhutch.org

United States1 site

  • Fred Hutch/University of Washington Cancer Consortium

    Seattle, Washington, 98109

    Fred Hutch Intake, 206-606-1024, hutchdoc@fredhutch.org

    Rosa Nadal Rios, MD, PhD

Other trials in United States

About this study

Official title: Phase 1 Dose-Escalation and Expansion Study of IL-18 Armored STEAP1 CAR T in Participants With mCRPC

This phase I trial tests the safety, side effects, best dose and how well giving IL-18 armored STEAP1 CAR T cells after lymphodepleting chemotherapy (with cyclophosphamide and fludarabine) works for the treatment of castration resistant prostate cancer that has spread from where it first started (primary site) to other places in the body (metastatic). Giving chemotherapy, with cyclophosphamide and fludarabine, prior to CAR T cells helps kill cancer cells in the body and prepare the body to receive the CAR T cells. Chimeric antigen receptor (CAR) T-cell therapy is a type of treatment in which a patient's T cells (a type of immune system cell) are changed in the laboratory so they will attack cancer cells. T cells are taken from a patient's blood. Then the gene for a special receptor that binds to a certain protein on the patient's cancer cells is added to the T cells in the laboratory. The special receptor is called a chimeric antigen receptor. Large numbers of the CAR T cells are grown in the laboratory and given to the patient by infusion for treatment of certain cancers. Giving IL-18 armored STEAP1 CAR T cells after lymphodepleting chemotherapy may be safe, tolerable and/or effective in treating patients with metastatic castration resistant prostate cancer.

Read the detailed description

OUTLINE:

Patients undergo leukapheresis. Patients receive cyclophosphamide intravenously (IV) and fludarabine IV on days -5 to -3. Patients receive FH-STEAP1 IL-18 CAR T cell IV on day 0. Patients may continue to receive androgen deprivation therapy per standard of care, throughout the study. Patients undergo nuclear medicine bone scan, computed tomography (CT) scan, magnetic resonance imaging (MRI) and/or positron emission tomography (PET) scan, tumor biopsy and blood sample collection throughout the study. Patients may also undergo multigated acquisition (MUGA) scan or echocardiography during screening.

After completion of study treatment, patients are followed up on day +1, +3, +7, +10, +14, +21, + 28, months 2-6, month 9, month 12, then every 6 months until year 5 then yearly until year 15.

Being tested
FH-STEAP1 IL-18 CAR T cells, Antiandrogen Therapy, Biospecimen Collection, Bone Scan, Computed Tomography
Medical subject headings
Prostatic Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FH-STEAP1 IL-18 CAR T cellsBiological

    Also called Drug Monotherapy, Single Agent Treatment, Single Drug Therapy

    Given FH-STEAP1 IL-18 CAR T cells IV

  • Antiandrogen TherapyDrug

    Also called ADT, Androgen Deprivation Therapy, Anti-androgen Therapy, Anti-androgen Treatment

    Receive standard of care androgen deprivation therapy

  • Biospecimen CollectionProcedure or surgery

    Also called Biological Sample Collection, Biospecimen Collected, Sample Collection, Specimen Collection

    Undergo blood sample collection

  • Bone ScanProcedure or surgery

    Also called Bone Scintigraphy

    Undergo nuclear medicine bone scan

  • Computed TomographyProcedure or surgery

    Also called CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography

    Undergo CT scan

  • CyclophosphamideDrug

    Also called (-)-Cyclophosphamide, 2H-1,3,2-Oxazaphosphorine, 2-[bis(2-chloroethyl)amino]tetrahydro-, 2-oxide, monohydrate, Asta B 518, B 518

    Given IV

  • Echocardiography TestProcedure or surgery

    Also called EC, Echocardiography

    Undergo echocardiography

  • FludarabineDrug

    Also called Fluradosa

    Given IV

  • LeukapheresisProcedure or surgery

    Also called Leukocyte Adsorptive Apheresis, Leukocytopheresis, Therapeutic Leukopheresis, White Blood Cell Reduction Apheresis

    Undergo leukapheresis

  • Magnetic Resonance ImagingProcedure or surgery

    Also called Magnetic Resonance, Magnetic Resonance Imaging (MRI), Magnetic resonance imaging (procedure), Magnetic Resonance Imaging Scan

    Undergo MRI

  • Multigated Acquisition ScanProcedure or surgery

    Also called Blood Pool Scan, Equilibrium Radionuclide Angiography, Gated Blood Pool Imaging, Gated Heart Pool Scan

    Undergo MUGA scan

  • Positron Emission TomographyProcedure or surgery

    Also called Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron emission tomography (procedure)

    Undergo PET scan

  • Biopsy ProcedureProcedure or surgery

    Also called BIOPSY_TYPE, Bx

    Undergo tumor biopsy

Study groups in NCT07803653
Study groupRoleWhat they receive
Treatment (chemotherapy, FH-STEAP1 IL-18 CAR T cells)ExperimentalPatients undergo leukapheresis. Patients receive cyclophosphamide intravenously (IV) and fludarabine IV on days -5 to -3. Patients receive FH-STEAP1 IL-18 CAR T cell IV on day 0. Patients may continue to receive androgen deprivation therapy per standard of care, throughout the study. Patients undergo nuclear medicine bone scan, CT scan, MRI and/or PET scan, tumor biopsy and blood sample collection throughout the study. Patients may also undergo MUGA scan or echocardiography during screening.
Receives: Biological: FH-STEAP1 IL-18 CAR T cells; Drug: Antiandrogen Therapy; Procedure: Biospecimen Collection; Procedure: Bone Scan; Procedure: Computed Tomography; Drug: Cyclophosphamide; Procedure: Echocardiography Test; Drug: Fludarabine; Procedure: Leukapheresis; Procedure: Magnetic Resonance Imaging; Procedure: Multigated Acquisition Scan; Procedure: Positron Emission Tomography; Procedure: Biopsy Procedure

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Treatment-related unexpected grade 3 or higher toxicity

    Measured: Up to 28 days post infusion

  2. Incidence of adverse events

    Measured: Up to 28 days post infusion

  3. Prostate cancer response

    Assessed by Prostate Cancer Working Group 3 (PCWG3) criteria.

    Measured: Up to 1 year post infusion

Secondary outcomes (7)

  1. Progression free survival

    Will be analyzed using Kaplan-Meier method and the results will be summarized by the median with a 95% confidence interval if appropriate.

    Measured: From initiation of protocol treatment to disease progression or death of any cause, up to 1 year post infusion

  2. Overall survival

    Will be analyzed using Kaplan-Meier method and the results will be summarized by the median with a 95% confidence interval if appropriate.

    Measured: From initiation of protocol treatment to death of any cause, up to 1 year post infusion

  3. Objective response rate

    Defined as complete response or partial response by Response Evaluation Criteria in Solid Tumors 1.1 criteria and PCWG 3.

    Measured: Up to 1 year post infusion

  4. Stable disease

    Assessed by RECIST 1.1 criteria and PCWG3.

    Measured: Up to 1 year post infusion

  5. Clinical benefit

    Defined as overall response and stable disease assessed by RECIST 1.1 criteria and PCWG3.

    Measured: Up to 1 year post infusion

  6. Overall response

    Assessed by immune RECIST criteria.

    Measured: Up to 1 year post infusion

  7. Prostate specific antigen (PSA) response

    Defined as ≥ 50% reductions in PSA. The estimation with an exact 95% confidence interval will be provided.

    Measured: From baseline, up to 15 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Sep 2026
  2. Study start31 Oct 2026 (estimated)
  3. Primary completion31 Oct 2030 (estimated)
  4. Study completion31 Oct 2044 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07803653
Sponsor's protocol ID
RG1126433
Other IDs
NCI-2026-06012, FH21226
Status last verified
Aug 2026
First submitted
28 Aug 2026
Last updated
4 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing FH-STEAP1 IL-18 CAR T cells, Antiandrogen Therapy and Biospecimen Collection in people with Metastatic Castration-Resistant Prostate Adenocarcinoma and Stage IVB Prostate Cancer AJCC v8, run by Fred Hutchinson Cancer Center at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 20 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 4 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Fred Hutch Intake (206-606-1024, hutchdoc@fredhutch.org), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Treatment-related unexpected grade 3 or higher toxicity (time frame: Up to 28 days post infusion). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07803653.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2026.

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