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Metastatic Castration-resistant Prostate CancerPhase 1/2NCT05570994

177Lu-HTK03170 in mCRPC With PSMA Positive Disease

A Phase 1/2 study testing 177Lu HTK03170 and 68Ga-HTK03149 in people with Metastatic Castration-resistant Prostate Cancer and Prostate Cancer Metastatic, run by British Columbia Cancer Agency at 1 site in Canada.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts
Official record
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Trial summary

This study will determine the safe initial injected activity of the radioligand therapy 177Lu-HTK03170 for the measurement of dosimetry and initiation of treatment in subjects with PSMA-positive, metastatic castrate resistant prostate cancer, (mCRPC). Read more about this study

Who is it for?
Ages 18 years and older, men only
What is being tested?
177Lu HTK03170 and 68Ga-HTK03149
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
1 siteCanada
Study dates
1 Jan 2024to 1 May 2027
Phase
Phase 1/2
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

  • Each subject must meet all of the following inclusion criteria to be enrolled in the study:
  • Male subjects ≥ 18 years of age
  • Willing and able to provide consent
  • Life expectancy of > 6 months
  • Progression on treatment with abiraterone and/or enzalutamide, or similar next generation ARAT therapy, as determined by the investigator. Subjects who have received docetaxel in the castration-resistant setting are also eligible to participate. Prior treatment with a poly adenosine diphosphate-ribose polymerase (PARP) inhibitor is permitted.
  • Pathologically confirmed prostate adenocarcinoma
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  • Subjects must have evidence of biochemical or imaging progression. Progression is defined as any one of the following:
  • Prostate-specific antigen progression: two consecutive rising PSA values from a baseline measurement with an interval of ≥ 1 week between measurements. Minimum PSA at screening visit is ≥ 2.0 µg/L.
  • Soft tissue disease progression on chest, abdomen, pelvis CT or magnetic resonance imaging (MRI; RECIST v1.1)
  • Bone progression: ≥ 2 new lesions on bone scan
  • Eastern Cooperative Oncology Group (ECOG) performance score ≤2
  • Prior orchiectomy, or if on luteinizing hormone releasing hormone (LHRH) agonist/antagonist, then testosterone < 1.7 nmol/L or < 50 ng/dL
  • Adequate organ function:
  • Marrow i) Absolute neutrophil count ≥ 1.5 × 109 /L ii) Platelet count ≥ 100 ×109 /L iii) Hemoglobin ≥ 90 g/L with no transfusions in the past 2 weeks b) Kidney i) Estimated creatinine clearance ≥40 ml/min according to Cockroft-Gault equation: ((140 - age) × (weight in kg)) / (72 × (serum creatinine)) c) Liver: i) Bilirubin < 1.0 × upper limit of normal (ULN) (or if bilirubin is between 1.5 to 2 × ULN, must have a normal conjugated bilirubin) ii) Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3.0 × ULN in the absence of liver metastases, and) ≤ 5.0 × ULN in the presence of liver metastases.
  • Recovery from all previous cancer treatment toxicities to grade ≤ 2 (as per CTCAE 4.03)
  • Able to comply with scheduled visits, treatment plans, laboratory tests, imaging tests, and other procedures required and detailed in the protocol.
  • Must be surgically sterile or use adequate contraception for the duration of the therapy and 6 months after the end of therapy

Who cannot join

  • Subjects meeting any of the following exclusion criteria are not to be enrolled in the study.
  • Prior treatment with 225Ac-PSMA-617, 177Lu-PSMA, other radiolabeled therapeutic PSMA-ligands, or radio-immunotherapy
  • Any systemic anti-cancer therapy (e.g. chemotherapy, immunotherapy or targeted therapy) within 28 days prior to day of enrollment
  • Radiotherapy to target lesions (measurable disease) ≤ 4 weeks prior to enrolment
  • Known parenchymal brain metastases
  • Active epidural disease (treated epidural disease is permitted)
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  • History of risk factors for xerostomia (ie, head and neck radiation, Sjögren's disease) or pre-existing xerostomia Grade ≥1
  • Other concomitant active invasive cancer (except superficial non-melanomatous, non-metastatic skin cancer or non-invasive superficial transitional cell carcinoma [TCC])
  • Clinically significant cardiac disease including:
  • History of unstable angina pectoris, symptomatic pericarditis, or myocardial infarction within 6 months prior to study entry.
  • History of documented congestive heart failure (New York Heart Association [NYHA] functional classification III-IV) or cardiomyopathy.
  • Major surgery within 4 weeks of starting study treatment.
  • Unmanageable urinary tract obstruction or hydronephrosis

Trial locations and contacts

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

Canada1 site

  • BC Cancer

    Vancouver, British Columbia, V5Z 4E6

Other trials in Canada

About this study

Official title: A Phase I/II Study of 177Lu-HTK03170 in Metastatic, Castration-Resistant Prostate Cancer Subjects With Prostate-specific Membrane Antigen-positive Disease

This study will determine the safe initial injected activity of the radioligand therapy 177Lu-HTK03170 for the measurement of dosimetry and initiation of treatment in subjects with PSMA-positive, metastatic castrate resistant prostate cancer, (mCRPC). Subjects will receive treatment which will be escalated between cycles and personalized based on dosimetry calculations and imaging. In addition, antitumour activity will be measured by radiographic response, and further assessments of the treatment will be measured by CT imaging, ctDNA/ctRNA, PSA, PSMA PET/CT, and quality of life questionnaires. Subjects will be followed for 2 years or until they have progression and are switched to another systemic treatment.

Read the detailed description

Overall, up to 50 subjects will be enrolled to receive an injected activity (IA) of 177Lu-HTK03170. The IA's will be escalated based on personalized dosimetry at subsequent treatments (up to 5 cycles total).

Screening Phase: Subjects will be screened against the inclusion and exclusion criteria. A PSMA PET/CT scan using 68Ga-HTK03149 will be used to confirm PSMA positive disease. Those with confirmed PSMA positive disease with continue to one of the two Treatment Phases. Subjects will be informed which Phase they will be enrolled in.

Subjects will undergo a physical exam, complete a medical history questionnaire, a quality of life questionnaire, blood work, and a diagnostic CT.

Treatment summary per Phase:

The first 3 subjects will receive an initial Initial Acitivity (IA) of 1.1 GBq of 177Lu HTK03170, for the first cycle of treatment, assuming no toxicities occur requiring dose modification. Dosimetry will be performed to obtain absorbed organ dose and effective dose values. The initial IA used for dosimetry will be escalated to improve image quality, radiation dosimetry estimates, and potential efficacy. IA escalation will only occur on the initial dosimetry IA, with an increase of 30% over the initial IA (used for dosimetry) at each subsequent level (1.65 GBq, 2.5 GBq, 3.7 GBq) in up to 12 participants.

IA escalation will cease when a maximum tolerated injected activity (MTIA) is determined or a recommended safe initial IA has been identified based on an integrated assessment of safety, pharmacokinetics (PK), dosimetry, and preliminary antitumour activity data, if available.

Treatment Phase I: During the treatment phase, subjects will undergo up to 5 cycles of treatment. Each treatment cycle will be followed by dosimetry SPECT/CT scans on day 3 (72 +/- 24 hours) after treatment administration, and day 10 (10 days +/- 72 hours) after treatment administration. Additional dosimetry SPECT/CT scans will be completed during Cycle 1, on the day of treatment, and on day 1 (24 hours after treatment). After Cycle 3, a quality of life questionnaire will be completed again.

Treatment Phase II: During the treatment phase, subjects will be treated with an initial IA of 177Lu-HTK03170 at the MTD as determined during Phase I, or 1625 MBq, whichever is lower. Personalized dosimetry will be calculated for each subject as in Phase 1 so that subsequent treatments will be estimated to remain within the absorbed cumulative dose limits of 28Gy and 35Gy for kidneys and salivary glands, respectively, adjusted iteratively over the 3 remaining treatment cycles separated by 8 weeks. Each treatment cycle IA will be further adjusted to ensure a single dose exposure of 2Gy or less to the bone marrow, as needed. Fifteen (15) subjects will be enrolled in the first stage. When 6 or more subjects achieve objective radiographic response based on RECIST v1.1 , the study will proceed to the 2nd stage, where additional 17 subjects will be enrolled to continue efficacy evaluation.

Subjects will undergo up to 5 cycles of treatment. Each treatment cycle will be followed by dosimetry SPECT/CT scans on day 1 (18 - 32 hours after treatment administration) and day 3 (64 - 80h after treatment administration). Additional dosimetry SPECT/CT scans will be completed during Cycle 1, on the day of treatment, and on day 10. A repeat After cycle 5 a quality of life questionnaire will be completed again.

Follow up Phase: At the end of treatment or after discontinuation of any cause, subjects will be followed for 2 years to continue data collection for the other objectives. Objective tumour response will be assessed every 4 months by diagnostic CT according to the RECIST 1.1 criteria. A final quality of life questionnaire will be completed again within 28 days after the last treatment.

Being tested
177Lu HTK03170, 68Ga-HTK03149

What participants receive

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

  • 177Lu HTK03170Drug

    Subjects will receive 177Lu HTK03170 treatment over 5 cycles, each cycle occurs every 8 weeks.

  • 68Ga-HTK03149Drug

    68Ga-HTK03149 PET/CT imaging; intravenous during screening

Study groups in NCT05570994
Study groupRoleWhat they receive
177Lu HTK03170 Phase I/IIExperimentalPhase I, the administered activity will be 1.1 GBq ± 10% as an intravenous infusion over a time of 10 to 30 minutes. Initial Activity (IA) escalation will only occur on the initial dosimetry IA, with an increase of 30% over the initial IA (used for dosimetry) at each subsequent level ( 1.65 GBq, 2.5 GBq, 3.7 GBq) in up to 12 participants. Personalized dosimetry will be calculated for each subject. Phase II, subjects will be treated with an initial IA of 177Lu-HTK03170 at the MTIA as determined during Phase I or 13.7 GBq whichever is lower. Treatment is administered as an intravenous infusion over a time of 10 - 30 minutes. Personalized dosimetry will be calculated for each subject so that subsequent treatments will be estimated to remain within the absorbed cumulative dose limits of 28Gy and 35Gy for kidneys and salivary glands, adjusted iteratively over the 4 remaining treatment cycles separated by 8 weeks. Up to 32 subjects will be enrolled to continue efficacy evaluation.
Receives: Drug: 177Lu HTK03170; Drug: 68Ga-HTK03149

What is being measured

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

  1. To measure the radiation dosimetry of 177Lu-HTK03170 in subjects who have PSMA-positive mCRPC (confirmed by PSMA PET/CT) previously treated with ARAT

    Phase I: Absorbed doses to organs and tumors per unit of administered activity (Gy/MBq)

    Measured: Within 8 weeks of treatments per cycle (cycle durations = 8 weeks)

  2. To determine the MTIA or a recommended safe initial IA of 177Lu-HTK03170 to measure dosimetry and initiate treatment

    Phase I: Occurrence of dose limiting toxicity (DLT) per protocol

    Measured: Within 8 weeks of treatments per cycle (cycle durations = 8 weeks)

  3. To determine the number of subjects with AEs, Grade 3 or above AEs, drug-related AEs, and SAEs, based on CTCAE v4.03.

    Proportion and distribution of adverse events (AE) is done via the analysis of frequencies for treatment emergent Adverse Event and Serious Adverse Event through the monitoring of relevant clinical and laboratory safety parameters.

    Measured: Within 8 weeks of treatments per cycle (cycle durations = 8 weeks)

  4. To determine the number of subjects with AEs leading to discontinuation

    Proportion of subjects who permanently discontinue 177Lu-HTK03170 due to toxicity or hypersensitivity

    Measured: up to 8 weeks post treatment cycle up to 14 weeks post cycle

  5. Determine the number of subjects with markedly abnormal laboratory tests (including ECG) at least once post-injection

    Analysis of the number of subjects with abnormal labs or ECG data parameters as determined by lab assessment reports and 12-lead electrocardiogram (ECG) reporting

    Measured: up to 8 weeks post treatment cycle

  6. To determine the antitumour effect of 177Lu-HTK03170 therapy measured by radiographic ORR per RECIST v1.1 in subjects who have PSMA-positive mCRPC

    Proportion of subjects achieving a PR, or CR, based on RECIST v1.1

    Measured: up to 24 months subsequent follow up evaluations

Secondary outcomes (8)

  1. Overall Response Rate (ORR)

    Proportion of subjects achieving a stable disease lasting for at least 6 months based on RECIST v1.1

    Measured: at least 6 months subsequent follow-up evaluations

  2. Percentage of Participants Achieving Prostate-specific Antigen (PSA) Response

    Proportion of subjects achieving prostate-specific antigen (PSA) responses defined as a decline of ≥50% decline from baseline

    Measured: from date of baseline assessment to at least 4 weeks post treatment cycle Within 8 weeks of treatments per cycle (cycle durations = 8 weeks)

  3. Duration of PSA responses

    Duration of PSA response was defined as the duration between the date of first document PSA response (i.e. >= 50% decrease in PSA from Baseline) and the earliest date of PSA progression, where date of PSA progression was defined as: 1) Where a decline from baseline was documented, date that a >= 25% increase in PSA and an absolute increase of 2 ng/mL or more from the nadir was documented and confirmed by a second consecutive value obtained at least 4 weeks later.

    Measured: From date of first documented PSA response till 4 weeks follow up, assessed up to 24 months post end of last cycle

  4. Duration of radiographic response

    Duration of radiographic response was defined as the duration between the date of first documented Best Overall Response of Complete Response or Partial Response and the date of first documented radiographic progression or death due to any cause

    Measured: From first documented evidence of CR or PR (the response prior to confirmation) until time of documented disease progression or death due to any cause, whichever comes first, assessed up to 24 months from end of last cycle

  5. Progression free survival at 6 months

    Proportion of subjects who are progression-free at 6 months as defined by PSA, objective disease, or symptoms. PSA progression, radiographic progression, or clinical progression per PCWG3 criteria will be assessed separately and combined.

    Measured: From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to 6 months

  6. Progression-free Survival (PFS)

    Time to PSA progression, radiographic progression, or clinical progression per PCWG3 criteria will be assessed separately and combined.

    Measured: From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to 24 months post end of treatment cycle

  7. Time to First Symptomatic Skeletal Event (SSE)

    Time to first Symptomatic Skeletal Event (SSE) was defined as the time (in months) from the date of randomization to the date of the SSE or death from any cause. The SSE date was the date of first new symptomatic pathological bone fracture, spinal cord compression, tumor-related orthopedic surgical intervention, requirement for radiation therapy to relieve bone pain, or death due to any cause, whichever occurred first.

    Measured: From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to 24 months post end of treatment cycle

  8. Change From Baseline in the European Quality of Life (EuroQol) - 5 Domain 5 Level Scale (EQ-5D-5L) Utility Score

    The EQ-5D-5L is a standardized participant completed questionnaire that measures health-related quality of life. EQ-5D-5L consists of two components: a health state profile and an optional visual analogue scale (VAS). EQ VAS records the patient's self-rated health on a vertical visual analogue 0-100 scale, where the endpoints are labelled 'The best health you can imagine' and 'The worst health you can imagine'. The higher the EQ-VAS score, the better the QoL.

    Measured: Baseline (week 0), Cycle 3 (Day 1), Follow up (Day 84 of last treatment) (cycle duration for Cycle 1-5 = 8 weeks

Timeline

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

  1. First posted7 Oct 2022
  2. Study start1 Jan 2024
  3. Primary completion1 Dec 2026 (estimated)
  4. Study completion1 May 2027 (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 1/2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Sequential
Model description
This is a prospective phase I/II study 1-arm study of efficacy and safety of 177Lu HTK03170 for treatment of patients with mCRPC who are referred to BC Cancer - Vancouver for treatment of progressive tumours.
Masking
None (open label)
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05570994
Sponsor's protocol ID
H22-02395
Status last verified
Jan 2026
First submitted
27 Sep 2022
Last updated
8 Jan 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Harsini S, Soleimani M, Wilson D, Uribe C, Saprunoff H, Bloise I, Benard F. A Phase I/II Study of [177Lu]Lu-HTK03170 with Personalized Dosimetry in Patients with Metastatic Castration-Resistant Prostate Cancer: Clinical Trial Protocol. J Nucl Med. 2025 Jul 1;66(7):1061-1067. doi: 10.2967/jnumed.124.269064.

    PubMed 40306965

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing 177Lu HTK03170 and 68Ga-HTK03149 in people with Metastatic Castration-resistant Prostate Cancer and Prostate Cancer Metastatic, run by British Columbia Cancer Agency at 1 site in Canada.

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 17 inclusion and 13 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: enrolling by invitation, as of the sponsor's last update on 8 Jan 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 Canada. 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 combined 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.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

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?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

To measure the radiation dosimetry of 177Lu-HTK03170 in subjects who have PSMA-positive mCRPC (confirmed by PSMA PET/CT) previously treated with ARAT (time frame: Within 8 weeks of treatments per cycle (cycle durations = 8 weeks)). The study lists 6 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 NCT05570994, which also lists 1 linked publication.

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 8 Jan 2026.

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