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AzTrials

Metastatic Castration-resistant Prostate CancerPhase 3NCT06520345

The Study of 177Lu-TLX591 Plus SOC Versus SOC Alone in Patients With mCRPC (ProstACT Global)

A Phase 3 study testing 177Lu-TLX591, Enzalutamide and Abiraterone in people with Metastatic Castration-resistant Prostate Cancer, run by Telix Pharmaceuticals (Innovations) Pty Limited at 33 sites in 6 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

The purpose of this study is to evaluate the efficacy and safety of 177Lu-TLX591 in patients with metastatic castration-resistant prostate cancer who have progressed following treatment with Androgen Receptor Pathway Inhibitor Treatment Read more about this study

Who is it for?
Ages 18 years and older, men only
What is being tested?
177Lu-TLX591, Enzalutamide and Abiraterone
Could I receive a placebo?
No, everyone receives an active treatment
How many people
520 participants
Where
33 sitesin 6 countries
Study dates
26 Jul 2024to Dec 2030
Phase
Phase 3
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

  • Be a male, at least 18 years old, with documented adenocarcinoma of the prostate defined by histological / pathological confirmation.
  • Be of ECOG Performance Status 0, 1, or 2 and have an estimated life expectancy of ≥6 months from Day 1.
  • Have metastatic disease (defined as ≥1 metastatic lesion present on baseline CT, MRI or bone scintigraphy).
  • Have castration-resistant PC (defined as disease progressing despite castration by orchiectomy or ongoing use of luteinizing hormone-releasing hormone [LHRH] analogues) and must have a castrate level of serum/plasma testosterone (<50 ng/dL or <1.7 nmol/L) at Screening
  • Must have received a minimum of 12 weeks of prior therapy on an ARPI (abiraterone, apalutamide, darolutamide, or enzalutamide), received in either the mCSPC, nmCRPC, or mCRPC treatment settings, with documented evidence of disease progression while receiving this ARPI. Progression must have occurred on the most recent ARPI. A prior ARPI may have been utilized, but no progression on the prior ARPI is allowed (e,g, ARPI was switched due to poor tolerability or due to adverse events). No washout period is required prior to enrollment into this trial. Participants may have received docetaxel in the mCSPC setting as per the CHAARTED or STAMPEDE treatment regimens (up to 6 cycles of docetaxel), provided the last dose of docetaxel was ≥ 6 months prior to screening and ≥ 4 cycles of docetaxel were administered.
  • Have a disease that is progressing at study entry, despite a castrate testosterone level (<50 ng/dL or <1.7 nmol/L), by the demonstration of at least one of the following:
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  • Two consecutive rising PSA values assessed sequentially at least one week apart, with the final measurement required to be a minimum of 2.0 ng/mL for study entry. Only the last measurement must meet or exceed 2.0 ng/mL.
  • Progressive disease or new lesion(s) in the viscera or lymph nodes as per RECIST1.1 or in bone as per PCWG3. Any ambiguous results are to be confirmed by other imaging modalities (e.g., CT or MRI scan).
  • Have disease that is PSMA-positive, as demonstrated by a 68Ga-PSMA-11 PET/CT or PET/MRI scan and confirmed as eligible by the Sponsor's appointed BICR.
  • Imaging-based eligibility review will be performed in two stages:
  • Presence of metastases for exclusion: Screening CT and MRI will be assessed to exclude participants with brain metastasis with long-axis>1cm
  • PSMA PET eligibility: Screening 68Ga-PSMA-11 PET/CT or PET/MRI will be assessed along with CT, MRI, and bone scans utilizing tumor to liver ratio (TLR) for PSMA positivity-based exclusion. TLR is defined as the ratio of tumor lesion SUVmax to liver SUVmean derived from a 3 cm 3D spherical region of interest (ROI).
  • PSMA positivity is defined as : At least 1 lesion with PSMA TLR≥2.
  • PSMA exclusion critieria: The presence of any of the following will result in the patient being ineligible for this trial:
  • visceral metastatic lesions that are ≥1 cm that have a PSMA TLR< 1 ii) Lytic bone metastatic lesions with a soft tissue component of at least 1 cm with a TLF <1.
  • At least one metastatic lymph node lesion with short axis ≥2.5 cm with a TLF<1.
  • Must have recovered to ≤ Grade 2 from all clinically significant toxicities related to prior therapies (i.e., surgery, local radiotherapy, ARPI, chemotherapy, etc.) with the exception of alopecia. Specific conditions may be discussed with the medical monitor as needed.
  • Have adequate organ function at Screening:
  • Bone marrow:
  • Platelets ≥150×109/L.
  • Absolute neutrophil count ≥1.5 x 109/L.
  • Hemoglobin >10g/dL (with no red blood cell transfusion in the previous 4 weeks).
  • Liver function:
  • Total bilirubin ≤ 1.5× the upper limit of normal (ULN). For participants with known Gilbert's Syndrome ≤3× ULN is permitted.
  • Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤3× ULN.
  • Renal function:
  • Creatinine clearance ≥45 mL/min determined using the Cockcroft-Gault formula.
  • Must understand the study and agree to adhere to all protocol requirements.
  • Participants must comply with the radiation protection rules (including hospital admissions and isolation) that are used by the treating institution to protect their contacts and the public, especially if a female partner of the participant is or could be pregnant.
  • Must agree to practice adequate precautions to prevent pregnancy in a partner and to avoid potential problems associated with radiation exposure to the unborn child (Recommendations related to contraception and pregnancy testing in clinical trials Version 1.1 [Clinical Trial Coordination Group {CTCG, 2024}]).

Who cannot join

  • Is unable to understand or is unwilling to sign a written informed consent document or to follow investigational procedures in the opinion of the Investigator.
  • Has PC associated with pathological findings consistent with small cell or any histology other than adenocarcinoma of the prostate. If there are minor (<20%) elements of neuroendocrine histology, this is acceptable.
  • Participants with a history of other malignancies that could significantly impact life expectancy or interfere with disease assessment will be excluded. Exceptions apply to participants with:
  • Prior malignancy that has been adequately treated and has remained disease-free for at least 3 years (maybe confirmed by a scan, etc.).
  • Adequately treated non-melanoma skin cancer.
  • Superficial (non-muscle invasive) bladder cancer that is controlled and stable.
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  • Has received prior treatment with monoclonal antibody (mAb) J591 or HuJ591 or any other PSMA targeted therapy.
  • Have received chemotherapy in the mCRPC or non-metastatic prostate cancer (nmCRPC) settings (note: prior docetaxel use in the mCSPC setting with CHAATERED or STAMPEDE regimens is permitted if the last dose of therapy was ≥6 months prior to screening and ≥4 cycles of docetaxel were administered).
  • Has known allergies, hypersensitivity, or intolerance to the investigational drug or its excipients.
  • Has received prior systemic anti-cancer therapy (e.g., chemotherapy, immunotherapy, or biological therapy) and/or radiation therapy within 4 weeks of enrolment (excluding ARPI and/or LHRH analogues).
  • OR are receiving other concurrent cytotoxic chemotherapy, immunotherapy, radioligand therapy, or investigational therapy.
  • Has received prior treatment with radioisotopes, including but not limited to: 89Strontium, 153Samarium, 186Rhenium, 188Rhenium, 223Radium, or hemi-body irradiation within 6 months prior to enrolment.
  • Has received other investigational therapy within 4 weeks of enrolment.
  • Has known brain metastases with long-axis ≥1cm, or liver metastases with long-axis ≥1cm, or lytic bone metastases with long-axis ≥1cm.
  • Has a history of seizure and/or stroke within the past 6 months.
  • Has clinical or radiologic findings indicative of impending spinal cord compression or experience symptomatic spinal cord compression.
  • Has evidence of a serious active or sub-clinical infection or angina pectoris (New York Heart Association [NYHA] Class III or IV), significantly prolonged QT interval or other serious illness(es) involving the cardiac, respiratory, central nervous system, renal, hepatic or hematological organ systems, that might impair the ability to complete this study or could interfere with determination of causality of any adverse effects experienced in this study, or which require treatment that could interact with study treatment, particularly with enzalutamide.
  • Has received treatment with any PARP inhibitors (i.e., Olaparib) or with any platinum based anti-neoplastic drugs.

Trial locations and contacts

33 sites in 6 countries. Contact the study team or a site near you to ask about taking part.

33 sites in 6 countries

Australia12 sites, 12 recruiting

  • Mater Health Services Pty Ltd

    Brisbane, 4101

    Alice Hillman, +61 731637978, alice.hillman@mater.org.au

    Niara Oliveira

    Not yet recruiting

  • GenesisCare Maitland

    East Maitland, 2323

    Kristy Atherton, +61 249184519, kristy.atherton@genesiscare.com

    Sangeetha Ramanujan

    Recruiting

  • Austin Health

    Heidelberg, 3084

    Tina Chen, +61 3 9496 5748, tina.chen@austin.org.au

    Recruiting

  • GensisCare Cabrini

    Malvern, 3144

    Michelle Starmans, +61 448011828, michelle.starmans@genesiscare.com

    Mario Guerrieri

    Recruiting

  • Australian Prostate Centre

    Melbourne, Victoria, 3051

    Prof Tony Costello, +61 3 8373 7600, info@apcr.org.au

    Prof. Tony Costello

    Recruiting

  • GenesisCare North Adelaide

    North Adelaide, 5006

    Geetanjali Rangnekar, +61 882158010, geetanjali.rangnekar@genesiscare.com

    Tony Michele

    Recruiting

  • GenesisCare Murdoch

    Perth, Western Australia, 6150

    Study Coordinator, +61 8 9366 1500, kate.waswo@genesiscare.com

    Dr. Aviral Singh

    Recruiting

  • Royal North Shore Hospital

    Saint Leonards, 2065

    Sally McCowatt, +61 294631181, Sally.McCowatt@health.nsw.gov.au

    Alexander Guminski

    Recruiting

  • Westmead Hospital

    Sydney, New South Wales, 2143

    Westmead Hospital, +61 2 8890 5200, wslhd-cpmcc-enquiries@health.nsw.gov.au

    Study Coordinator, +61 2 8890 8383

    Recruiting

  • Nepean Hospital

    Sydney, New South Wales, 2747

    Study Coordinator, +61 2 4734 2156, Nbmlhd-nm-research@health.nsw.gov.au

    Dr. Veronica Wong

    Recruiting

  • GenesisCare Tugun

    Tugun, 4224

    Kristy Longhurst, +61 477 007 925, kristy.longhurst@genesiscare.com

    Sagar Ramani

    Recruiting

  • Wollongong Hospital

    Wollongong, New South Wales, 2500

    Carly Leighton, +61 2 4222 5200, ISLHD-CancerClinicalTrials@health.nsw.gov.au

    Dr. Gary Tincknell

    Recruiting

Other trials in Australia

United States9 sites, 1 recruiting

  • University Hospital

    Cleveland, Ohio, 44106

    Active, not recruiting

  • United Theranostics

    Glen Burnie, Maryland, 21061

    Active, not recruiting

  • Biogenix Molecular LLC

    Miami, Florida, 33165

    Active, not recruiting

  • Intermountain Health

    Murray, Utah, 84107

    Active, not recruiting

  • Columbia University Herbert Irving Comphrensive Cancer Center

    New York, New York, 10032

    Lisa Sahadi, 7322352466, mns2146@cumc.columbia.edu

    Mark Stein

    Recruiting

  • XCancer Omaha

    Omaha, Nebraska, 68130

    Active, not recruiting

  • Chao Family Comprehensive Cancer Centre

    Orange, California, 92868

    Active, not recruiting

  • OHSU Knight Cancer Center

    Portland, Oregon, 97239

    Active, not recruiting

  • Intermountain Health

    Salt Lake City, Utah, 84112

    Active, not recruiting

Other trials in United States

Turkey (Türkiye)4 sites, 4 recruiting

  • Ankara Bilkent City Hospital

    Ankara

    Can Abdan, +90 5309562789, can.abdan@rivercro.com

    Samet Taştan, +90 554 242 0670, samet.tastan@rivercro.com

    Not yet recruiting

  • Ankara University Cebeci Hospital

    Ankara

    Özlem Üstündağ, 0 541 669 39 59, ozlem_ustundag@cellin.com.tr

    Yüksel Ürün, +90 533 748 32 75, dr.yukselurun@gmail.com

    Recruiting

  • Hacettepe University Medical Faculty

    Ankara

    Eda Karabulut, +90 5359673678, eda.karabulut@medex-smo.com

    Murat Bozkurt, (+90) 0532 492 4890, fanibozkurt@yahoo.com

    Recruiting

  • Maslak Acibadem Hospital

    Istanbul

    Nur Ergin, 90 (505) 558 70 45, beyzanur.ergin@medismart.com.tr

    Doğukan Danışmant, +90 545 862 87 19, dogukan.danismant@medismart.com.tr

    Recruiting

Other trials in Turkey (Türkiye)

United Kingdom4 sites, 4 recruiting

  • Charing Cross Hospital

    London

    Amalia Saucan, 02033115308, Amalia.saucan@nhs.net

    Naveed Sarwar

    Recruiting

  • Royal Free Hospital

    London

    Hannah Powell, 02077940500 ext. 38683, hannah.powell3@nhs.net

    Mark Prentice

    Not yet recruiting

  • University College London Hospitals

    London

    GU Research, uclh.GU-Research@nhs.net

    Ursula McGovern

    Recruiting

  • Genesiscare Windsor

    Windsor

    Nicola Dallas, 01753 418444, contactus@genesiscare.co.uk

    Nicola Dallas

    Recruiting

Other trials in United Kingdom

Canada2 sites, 2 recruiting

  • INITIO Medical Group

    Burnaby

    Philip Cohen, 604-678-9274, clinicaltrials@initiomedical.ca

    Recruiting

  • Sunnybrook Research Institute

    Toronto

    Urban Emmenegger, (416) 480-6100 ext. 64928, urban.emmenegger@sunnybrook.ca

    Urban Emmenegger

    Recruiting

Other trials in Canada

New Zealand2 sites, 2 recruiting

  • New Zealand Clinical Research - Christchurch

    Christchurch, 8011

    Gill Savin, +6433729477, Prostact.christchurch@nzcr.co.nz

    Anthony Rahman

    Recruiting

  • Auckland City Hospital

    Grafton, Auckland, 92024

    Sergei Bendrikovskii, +64 93074949, Ak-Researchassistant@TeWhatuOra.govt.nz

    Simon Fu

    Recruiting

Other trials in New Zealand

About this study

Official title: A Multinational, Multicenter, Prospective, Randomized, Controlled, Open-Label, Phase 3 Study of Lutetium (177Lu) Rosopatamab Tetraxetan in Combination With Standard of Care Versus Standard of Care Alone in Patients With PSMA Positive Metastatic Castration-Resistant Prostate Cancer Previously After Androgen Receptor Pathway Inhibitor Treatment

The purpose of this study is to evaluate the efficacy and safety of 177Lu-TLX591 in patients with metastatic castration-resistant prostate cancer who have progressed following treatment with Androgen Receptor Pathway Inhibitor Treatment

Read the detailed description

The primary objective of the study is to compare radiographic progression-free survival (rPFS) in participants who receive 177Lu-TLX591 with SOC to rPFS in participants who receive SOC only.

This study consists of three Parts:

  • Part 1: Safety and Dosimetry Lead-in,
  • Part 2: Randomized Treatment Expansion, and
  • Part 3: Long-term Follow-up

The study will commence with a 30-patient safety and dosimetry lead-in (Part 1) and proceed to a randomization treatment expansion in approximately 490 patients (Part 2).

Patients in Part 2 will be randomized in a 2:1 ratio to receive either 177Lu-TLX591 + Standard of Care SoC (Group A), or SoC alone (Arm B).

SoC in this trial is either: ARPI (enzalutamide or abiraterone) or docetaxel.

All patients will be followed in long-term follow-up for at least 5 years from the first therapeutic dose, death, or loss to follow up (Part 3).

Only patients that meet PSMA-positivity criteria per Blinded Independent Central Review (BICR) will be eligible for this study.

Being tested
177Lu-TLX591, Enzalutamide, Abiraterone, Docetaxel
Keywords
Radiographic Progression Free Survival, Overall Survival, ARPI, Docetaxel, Prostate Cancer, Radionuclide therapy, TLX591, ProstACT Global, PSMA- targeting agent, mCRPC, 177Lu-TLX591, mCSPC, nmCRPC, rosopatamab tetraxetan, Lutetium, 177-Lutetium, Objective Response Rate (ORR), PSA, 68Gallium-PSMA-PET, Radio-Labelled Antibody Drug Conjugate (rADC)
Medical subject headings
Prostatic Neoplasms

What participants receive

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

  • 177Lu-TLX591Drug

    Also called Lutetium (177Lu) rosopatamab tetraxetan

    Participants randomized to Group A will receive two 76 mCi (±10%) doses of 177Lu-TLX591 14 days apart

  • EnzalutamideDrug

    Enzalutamide (starting dose 160 mg daily)

  • AbirateroneDrug

    Abiraterone (starting dose 1,000 mg daily) + prednisone / prednisolone (up to 10 mg per day for the standard formulation)

  • DocetaxelDrug

    Docetaxel: Single agent chemotherapy will consist of docetaxel given at a recommended dose of 75mg/m2 IV every 3 weeks given in combination with oral prednisone / prednisolone 5mg twice a day (or equivalent) for up to 10 cycles

Study groups in NCT06520345
Study groupRoleWhat they receive
177Lu-TLX591 + Enzalutamide or Abiraterone or DocetaxelExperimentalLutetium (177Lu) rosopatamab tetraxetan (177Lu-TLX591) 76 mCi (±10%) given approximately 14 days apart, plus SOC. SOC is either: Concurrent enzalutamide (starting dose 160 mg daily) + prednisone / prednisolone (5 mg twice a day) or equivalent. or Concurrent abiraterone (starting dose 1,000 mg daily) + prednisone / prednisolone (5 mg once daily for the standard formulation), methylprednisolone (4 mg twice daily for the fine particle formulation) or dexamethasone (1 mg once daily) or Sequential Docetaxel: Single agent chemotherapy will consist of docetaxel given at a recommended dose of 75mg/m2 IV every 3 weeks given in combination with oral prednisone / prednisolone (5mg twice a day) or equivalent for up to 10 cycles.
Receives: Drug: 177Lu-TLX591; Drug: Enzalutamide; Drug: Abiraterone; Drug: Docetaxel
Control Arm (Enzalutamide or Abiraterone or Docetaxel)Active comparatorSOC is either: Enzalutamide (starting dose 160 mg daily). or Abiraterone (starting dose 1,000 mg daily) + prednisone / prednisolone (up to 10 mg once daily for the standard formulation) or Docetaxel: Single agent chemotherapy will consist of docetaxel given at a recommended dose of 75mg/m2 IV every 3 weeks given in combination with oral prednisone / prednisolone 5mg twice a day (or equivalent) for up to 10 cycles
Receives: Drug: Enzalutamide; Drug: Abiraterone; Drug: Docetaxel

What is being measured

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

  1. Radiographic Progression-free Survival

    time from randomization to disease progression confirmed by central independent radiology review according to Prostate Cancer Clinical Trials Working Group 3 (PCWG3) criteria (which incorporates Response Evaluation Criteria in Solid Tumors, RECIST 1.1, for soft tissue lesions), or death (whichever occurs first)

    Measured: 337days

Secondary outcomes (3)

  1. Overall Survival

    Defined as the time from randomization, until death from any cause.

    Measured: 5 years

  2. Objective Response Rate (ORR)

    Tumor response in terms of PCWG3 criteria (which incorporates RECIST 1.1 for soft tissue lesions).

    Measured: 337days

  3. Time to a first symptomatic skeletal event (SSE)

    Time to a first SSE, defined as the use of external beam radiation to relieve bone pain, or occurrence of a new symptomatic pathological fracture (vertebral or non-vertebral), or occurrence of spinal cord compression, or tumor-related orthopedic surgical intervention.

    Measured: 337days

Timeline

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

  1. First posted25 Jul 2024
  2. Study start26 Jul 2024
  3. Primary completionDec 2027 (estimated)
  4. Study completionDec 2030 (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 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
This is a multinational, multicenter, prospective, randomized, controlled, open-label Phase 3 study designed to investigate and confirm the benefits and risks associated with 177Lu-TLX591 administered together with SOC compared to SOC alone, in participants with PSMA-positive metastatic castration resistant prostate cancer (mCRPC) who have progressed after their first treatment with an ARPI (specifically abiraterone, apalutamide, darolutamide or enzalutamide) or docetaxel administered during either the metastatic castrate-sensitive prostate cancer (mCSPC), non-metastatic castration resistant prostate cancer (nmCRPC) or first-line metastatic castrate-resistant prostate cancer (mCRPC) treatment setting.
Masking
None (open label)
Enrolment
520 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06520345
Sponsor's protocol ID
177Lu-TLX591-203
Status last verified
Jul 2026
First submitted
12 Jul 2024
Last updated
21 Jul 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing 177Lu-TLX591, Enzalutamide and Abiraterone in people with Metastatic Castration-resistant Prostate Cancer, run by Telix Pharmaceuticals (Innovations) Pty Limited at 33 sites in 6 countries.

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 30 inclusion and 18 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: looking for participants now, as of the sponsor's last update on 21 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 33 sites in Australia, United States, Turkey (Türkiye), United Kingdom, Canada and 1 more country. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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?

Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Radiographic Progression-free Survival (time frame: 337days). 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 NCT06520345.

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 21 Jul 2026.

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