AcTFirst: A Phase III, Open-Label, Multi-Center, Randomized Study Comparing AAA817+ARPI Versus Standard of Care in Adult Participants with PSMA-positive Metastatic Castration Resistant Prostate Cancer
Study 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.
Eligibility
- Participants must have histological, and/or cytological confirmation of adenocarcinoma of the prostate. Participants with mixed histology (neuroendocrine) are not eligible.
- Participant must have been diagnosed with mCRPC with documented progressive disease while on treatment with ARPI in metastatic hormone-sensitive prostate cancer (mHSPC) or earlier setting as their last treatment (and did not progress on more than one ARPI).
- 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.
Key
- 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.