NCT06855277 · Novartis Pharmaceuticals
Study Comparing AAA817+ARPI Versus Standard of Care in Adult Participants With PSMA-positive mCRPC
(AcTFirst)
What this study is about
The purpose of this study is to determine whether \[225Ac\]Ac-PSMA-617 (AAA817), given for up to 6 cycles at a dose of 10 Megabecquerel (MBq) +/- 10%, plus androgen receptor pathway inhibitor (ARPI), improves the radiographic time without the disease getting worse (rPFS) compared to investigator's choice of the usual treatment (SOC) (ARPI change or taxane-based chemotherapy or \[177Lu\]Lu-PSMA-617 (AAA617)) in adult participants with PSMA-positive metastatic castration resistant prostate cancer (mCRPC) treated with another ARPI as last treatment and who have not been exposed to a taxane-containing chemotherapy in the mCRPC setting nor have received any prior PSMA-targeting radioligand therapy.
View original scientific description
The purpose of this study is to determine whether \[225Ac\]Ac-PSMA-617 (AAA817), given for up to 6 cycles at a dose of 10 Megabecquerel (MBq) +/- 10%, plus androgen receptor pathway inhibitor (ARPI), improves the radiographic progression free survival (rPFS) compared to investigator's choice of standard of care (SOC) (ARPI change or taxane-based chemotherapy or \[177Lu\]Lu-PSMA-617 (AAA617)) in adult participants with PSMA-positive metastatic castration resistant prostate cancer (mCRPC) treated with another ARPI as last treatment and who have not been exposed to a taxane-containing chemotherapy in the mCRPC setting nor have received any prior PSMA-targeting radioligand therapy.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Signed informed consent must be obtained prior to participation in the study.
- Participants must be adults ≥ 18 years of age.
- Participants must have an ECOG performance status of 0 to 2.
- Participants must have histological, and/or cytological confirmation of adenocarcinoma of the prostate. Participants with mixed histology (neuroendocrine) are not eligible.
- Participants who have received taxane-based chemotherapy in mHSPC setting are eligible if they are deemed appropriate for chemotherapy, ARPI change or AAA617 as the next line of therapy in the opinion of the Investigator. Note: Participants who have received taxane-based chemotherapy for mCRPC are excluded.
- Participants must not have received taxane-based chemotherapy in mCRPC setting (allowed in mHSPC setting).
- Participants must have PSMA-PET positive disease using a PSMA imaging agent that is approved as per protocol.
- Participant must have been diagnosed with mCRPC with documented progressive disease while on treatment with ARPI in mHSPC or earlier setting as their last treatment (and did not progress on more than one ARPI).
- Participants with deleterious or suspected deleterious germline or somatic homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer, as per local testing, may be enrolled if they had prior exposure to PARPi. Key
Exclusion criteria
- Previous anti-cancer treatment with any approved or investigational radiopharmaceuticals (for example, \[177Lu\]Lu-PSMA, \[177Lu\]-DOTA, or Radium- 223.)
- Previous treatment with any external beam radiotherapy including hemi-body radiation within 6 weeks of randomization (within 2 weeks for radiotherapy of localized metastases).
- Any prior PARP inhibitor or other systemic anticancer therapy administered for metastatic castration-resistant prostate cancer (mCRPC). Any other approved or investigational systemic therapy (including chemotherapy, immunotherapy, biologics, or monoclonal antibodies) is prohibited within 28 days or 5 half-lives (whichever is shorter) before randomization. Note: Prior ARPI administered in the mHSPC setting or earlier may continue until C1D1. Other protocol-defined inclusion/exclusion criteria may apply.
Where
- Palo Alto, California
- Santa Barbara, California
- Denver, Colorado
- Miami, Florida
- Orlando, Florida
- Chicago, Illinois
- Iowa City, Iowa
- Kansas City, Kansas
- Metairie, Louisiana
- Boston, Massachusetts
- St Louis, Missouri
- Omaha, Nebraska
And 13 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 10, 2026 · Source of record for eligibility and locations