Phase I/II Study of [225Ac]Ac-PSMA-R2 in PSMA-positive Prostate Cancer, With/Without Prior 177Lu-PSMA RLT (SatisfACtion)

August 18, 2026 updated by: Novartis Pharmaceuticals

SatisfACtion: Phase I/II, Open-label, Multi-center Study of [225Ac]Ac-PSMA-R2 in Men With mHSPC and Heavily Pre-treated PSMA-positive mCRPC, With/Without Prior 177Lu-labelled PSMA-targeted Radioligand Therapy

The purpose of this study is to learn if the study drug, [225Ac]Ac-PSMA-R2, is safe and tolerable, and has anti-tumor activity in treated patients.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

First in human (FIH) phase I/II study of 225Ac-PSMA-R2 in PSMA-positive metastatic prostate cancer across three groups: post-177Lu mCRPC, pre-177Lu mCRPC, and 177Lu-naïve mHSPC, evaluating Q6W/Q4W dosing. Dose escalation will enroll ~18-22 participants per group/schedule to define MTD/RDE, guided by safety, tolerability, PK/dosimetry, and preliminary anti-tumor activity, with possible expansion based on benefit-risk.

Enrollment and dosing for all participants in Group 1, Group 2, and Group 3 have been completed. Further enrollment has been halted, and no additional dose escalation cohorts or Phase 2 dose expansion cohorts will be opened; enrollment in this study is now considered complete. The decision to halt enrolment was not driven by any safety concerns identified in the study to date, but rather by a lowered expectation of benefit. Accordingly, the study will not proceed to Phase 2, and a recommended Phase 2 dose was not established

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
33

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

  • Name: Novartis Pharmaceuticals
  • Phone Number: +41613241111

Study Locations

  • Australia
    • New South Wales
      • Darlinghurst, New South Wales, Australia, 2010
        • Novartis Investigative Site
  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H2X 1R9
        • Novartis Investigative Site
  • France
      • Clermont-Ferrand, France, 63011
        • Novartis Investigative Site
      • Lyon, France, 69373
        • Novartis Investigative Site
      • Nantes, France, 44093
        • Novartis Investigative Site
      • Saint-Herblain, France, 44805
        • Novartis Investigative Site
      • Vandœuvre-lès-Nancy, France, 54511
        • Novartis Investigative Site
    • Cote D Or
      • Dijon, Cote D Or, France, 21034
        • Novartis Investigative Site
  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic Rochester

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Evidence of PSMA-positive disease by 68Ga-PSMA-11 PET/CT and eligible as determined by central reading
  • Documented progressive mCRPC or mHSPC
  • Adequate organ function
  • Prior orchiectomy or ongoing ADT and should have received prior 177Lu-PSMA-RLT (Group1 dose escalation & expansion) or never received 177Lu-PSMA-RLT (Group 2 and Group 3 dose escalation & expansion).

Key Exclusion Criteria:

  • Any other investigational agents within 28 days of the anticipated C1D1 of 225Ac-PSMA-R2 therapy
  • Any systemic anti-cancer therapy within 28 days of the anticipated C1D1 of 225Ac-PSMA-R2 therapy
  • Uncontrolled pain or incompatibility that may result in participant's lack of ability to comply with imaging procedures
  • History of CNS metastases and symptomatic cord compression, or clinical or radiologic findings indicative of impending cord compression
  • History of myocardial infarction, angina pectoris, or coronary artery bypass graft within 6 months prior to ICF signature and/or clinically active significant cardiac disease
  • Diagnosis of other malignancies in the past three years expected to alter life expectancy or may interfere with disease assessment

Other protocol-defined inclusion/exclusion criteria may apply.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Group-1 (mCRPC/ post-177Lu)
  1. Dose Escalation: All eligible participants with Metastatic Castration Resistant Prostate Cancer (mCRPC) who have received anti-cancer treatment (post-Androgen Receptor Pathway Inhibitors (ARPI), post-taxane based chemotherapy and heavily pre-treated and having already received prior 177Lu-labelled Prostate Specific Membrane Antigen (PSMA)-targeting Radioligand Therapy (RLT) will receive the starting dose of 7 Megabecquerel (MBq) of 225Ac-PSMA-R2 to determine the Maximum Tolerated Dose/Recommended Dose for Expansion (MTD/RDE) of Group 1.
  2. Dose Expansion: Once RDE is determined for Group 1, participants who have previously received 177Lu-PSMA-RLT will be enrolled in Group 1 dose expansion.
Drug: 225Ac-PSMA-R2
PSMA-R2 is a ligand coupled with 225Ac an alpha emitting radionuclide
Radiation: 68Ga-PSMA-R2
Kit for radiopharmaceutical preparation
Radiation: 68Ga-PSMA-11
Kit for radiopharmaceutical preparation
Other Names:
  • Locametz
Experimental: Group-2 (mCRPC/ pre-177Lu)
  1. Dose Escalation: All eligible participants with mCRPC who have received anti-cancer treatment (post-Androgen Receptor Pathway Inhibitors (ARPI), prior taxane-based chemotherapy is not required, but have never been treated with 177Lu-labelled PSMA-targeted RLT (177Lu-labelled PSMA-targeted RLT treatment naïve) will receive the starting dose of 7 Megabecquerel (MBq) of 225Ac-PSMA-R2 to determine the Maximum Tolerated Dose/Recommended Dose for Expansion (MTD/RDE) of Group 2.
  2. Dose Expansion: Once RDE is determined for Group 2, participants naïve to 177Lu-labelled PSMA-targeted Radioligand Therapy (RLT) will be enrolled in Group 2 dose expansion.
Drug: 225Ac-PSMA-R2
PSMA-R2 is a ligand coupled with 225Ac an alpha emitting radionuclide
Radiation: 68Ga-PSMA-R2
Kit for radiopharmaceutical preparation
Radiation: 68Ga-PSMA-11
Kit for radiopharmaceutical preparation
Other Names:
  • Locametz
Experimental: Group 3 (mHSPC/ pre-177Lu)
  1. Dose Escalation: All eligible participants with mHSPC (177Lu-labelled PSMA-targeted RLT treatment naïve), who are treatment naive or minimally treated with a) luteinizing hormone-releasing hormone (LHRH) agonist/antagonists or bilateral orchiectomy with or without first generation antiandrogen (e.g. bicalutamide, flutamide) b) CYP17 inhibitor or ARDT exposure. Patient in this group will start treatment with 225Ac-PSMA-R2 after group 1 and group 2 patients.
  2. Dose Expansion: Once RDE is determined for Group 3, participants will be enrolled in Group 3 dose expansion.
Drug: 225Ac-PSMA-R2
PSMA-R2 is a ligand coupled with 225Ac an alpha emitting radionuclide
Radiation: 68Ga-PSMA-R2
Kit for radiopharmaceutical preparation
Radiation: 68Ga-PSMA-11
Kit for radiopharmaceutical preparation
Other Names:
  • Locametz

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Phase I Dose Escalation: Incidence and severity of DLTs during the DLT observation period
Time Frame: Up to 6 weeks after the first 225Ac-PSMA-R2 dose administration

To determine the Recommended Dose for Expansion (RDE) and corresponding regimen for 225Ac-PSMA-R2 monotherapy in PSMA-positive in:

  • Group-1 (mCRPC): Participants previously treated with 177Lu-labelled PSMA-targeted RLT (post-177Lu).
  • Group-2 (mCRPC): Participants not treated previously with 177Lu-labelled PSMA-targeted RLT (pre-177Lu).
  • Group-3 (mHSPC): Participants not treated previously with 177Lu-labelled PSMA-targeted RLT (pre-177Lu).
Up to 6 weeks after the first 225Ac-PSMA-R2 dose administration
Phase I Dose Escalation: Incidence and severity of adverse events (AEs) and serious adverse events (SAEs) by group and frequency schedule
Time Frame: From date of the first administration of 225Ac-PSMA-R2 till 30 days safety follow-up, assessed up to approximately 15 months
The distribution of adverse events will be done via the analysis of frequencies for treatment emergent Adverse Event (TEAEs), Serious Adverse Event (TESAEs) and Deaths due to AEs, through the monitoring of relevant clinical and laboratory safety parameters.
From date of the first administration of 225Ac-PSMA-R2 till 30 days safety follow-up, assessed up to approximately 15 months
Phase I Dose Escalation: Tolerability
Time Frame: Up to 6 weeks after the first 225AC-PSMA-R2 dose administration
Frequency of dose interruptions, reductions, discontinuations, and dose intensity by group.
Up to 6 weeks after the first 225AC-PSMA-R2 dose administration
Phase ll Dose Expansion: Overall Response Rate (ORR)
Time Frame: From date of the first administration of 225Ac-PSMA-R2 until date of radiographic progression or date of death from any cause, whichever comes first, assessed up to approximately 15 months
Overall Response Rate (ORR) is defined as the proportion of participants with confirmed best overall response (BOR) of complete response (CR) or partial response (PR) in soft tissue according to Prostate Cancer Working Group 3 (PCWG3) -modified RECIST v1.1 in absence of bone progression (as per PCWG3).
From date of the first administration of 225Ac-PSMA-R2 until date of radiographic progression or date of death from any cause, whichever comes first, assessed up to approximately 15 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Phase I Dose Escalation: Incidence and severity of AEs and serious adverse events (SAEs)
Time Frame: Up to 6 months after the last 225Ac-PSMA-R2 dose administration
Analysis of frequencies for treatment emergent Adverse Event (TEAEs), Serious Adverse Event (TESAEs) and Deaths due to AEs, through the monitoring of relevant clinical and laboratory safety parameters.
Up to 6 months after the last 225Ac-PSMA-R2 dose administration
Phase ll: Dose Expansion: Incidence and severity of AEs and serious adverse events (SAEs)
Time Frame: Assessed up to approximately 15 months.
Analysis of frequencies for treatment emergent Adverse Event (TEAEs), Serious Adverse Event (TESAEs) and Deaths due to AEs, through the monitoring of relevant clinical and laboratory safety parameters.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Dose Expansion: Frequency of dose interruptions, reductions, discontinuations, and dose intensity by treatment.
Time Frame: At day 1 of each cycle (1 cycle = up to 6 weeks)
Tolerability of study drug will be assessed by summarizing the number of and the reasons for dose delays and dose reductions. Dose intensity will also be tabulated by treatment group.
At day 1 of each cycle (1 cycle = up to 6 weeks)
Phase I Dose Escalation: Overall Response Rate (ORR)
Time Frame: Assessed up to approximately 15 months.
Overall Response Rate (ORR) is defined as the proportion of participants with best overall response (BOR) of complete response (CR) or partial response (PR) in soft tissue.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Disease Control Rate (DCR)
Time Frame: Assessed up to approximately 15 months.
Disease control rate (DCR) is defined as the proportion of participants with confirmed best overall response (BOR) of complete response (CR), partial response (PR) or stable disease (SD).
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Best Overall Response (BOR)
Time Frame: Assessed up to approximately 15 months.
Best Overall Response (BOR) is defined as the best response recorded from the start of the treatment until disease progression.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: radiographic Progression Free Survival (rPFS)
Time Frame: Assessed up to approximately 15 months.
Radiographic progression free survival (rPFS) is defined as the time (in months) from the date of the first administration of 225Ac-PSMA-R2 to the date of radiographic progression as outlined in PCWG3 modified RECIST 1.1 or death due to any cause.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Overall Survival (OS)
Time Frame: Assessed up to approximately 15 months.
Overall survival (OS) is defined as the time (in months) from the date of the first administration of 225Ac-PSMA-R2 to the date of death due to any cause.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Duration of Response (DoR)
Time Frame: Assessed up to approximately 15 months.
Duration of response (DOR) is defined as the time (in months) from the date of the first documented response (CR or PR) to the date of first documented progression.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Time to first Symptomatic Skeletal Event (SSE)
Time Frame: Assessed up to approximately 15 months.
Time to a first symptomatic skeletal event (SSE) is defined as the time (in months) from the first administration of 225Ac-PSMA-R2 to the date of SSE or death due to any cause.
Assessed up to approximately 15 months.
Phase I Dose Escalation & Phase II Dose Expansion: Percentage of Participants with Biochemical Response by ALP and LDH
Time Frame: Assessed up to approximately 15 months.
Biochemical responses by Alkaline Phosphatase (ALP) and Lactate Dehydrogenase (LDH) will be measured as best percentage change from baseline
Assessed up to approximately 15 months.
Phase I Dose Escalation and Phase II Dose Expansion: Percentage of Participants with Biochemical Response by PSA
Time Frame: Assessed up to approximately 15 months.
Biochemical responses as measured by Prostate Specific Antigen (PSA): PSA50 response is defined as the proportion of participants who have achieved ≥50% decrease from baseline at any time.
Assessed up to approximately 15 months.
Phase I Dose Escalation and Phase II: Dose Expansion: Pharmacokinetics characterization of 225Ac-PSMA-R2
Time Frame: At Cycle (C) 1 Day (D) 1 at different measurement times, and one timepoint at C1 D2, C1 D3 and C1 D4
Venous whole blood samples will be collected for activity-based pharmacokinetics characterization.
At Cycle (C) 1 Day (D) 1 at different measurement times, and one timepoint at C1 D2, C1 D3 and C1 D4
Phase I Dose Escalation and Phase II Dose Expansion: To assess the impact of 225Ac-PSMA-R2 on participant reported outcomes
Time Frame: From baseline until 24 months after the end of treatment
Change in heath related quality of life.
From baseline until 24 months after the end of treatment

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Novartis Pharmaceuticals

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Novartis Pharmaceuticals, Novartis Pharmaceuticals

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 7, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 4, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 4, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 24, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 8, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 9, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CAAA802A12101
  • 2021-003478-30 (EudraCT Number)

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

product manufactured in and exported from the U.S.

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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