AZD2265 Compared With Standard of Care in PSMA-positive Metastatic Castration-resistant Prostate Cancer (VECTRA-01)

Inclusion Criteria:

* ≥ 18 years of age.
* Diagnosis of adenocarcinoma of prostate.
* Must have had prior orchiectomy and/or ongoing ADT and a castrate level of plasma/serum testosterone.
* Progressive mCRPC following the most recent treatment at the time of study entry, with at least 1 metastatic lesion (measurable and/or non-measurable) that is suitable for repeated assessment by CT and/or MRI and/or bone scan.
* Previously treated with at least 2 cycles of PSMA-directed β-emitting radioconjugate.
* Previously treated with at least 1 taxane-based chemotherapy regimen for either metastatic hormone-sensitive prostate cancer or CRPC.
* Previously treated with at least 1 ARPI (eg, enzalutamide, abiraterone, etc.).
* Positive PSMA PET/CT scans, obtained with PSMA ligands (⁶⁸Ga-PSMA-11 or ¹⁸F-DCFPyL).
* ECOG performance status of 0 to 2.
* Adequate organ and bone marrow function as described in study protocol.
* Participants must not father children or donate sperm from signing ICF, during the study intervention and for 6 months after the last dose of study intervention.
* Participants must use a condom from signing ICF, during study intervention, and for 6 months after the last dose of study drug, with all sexual partners.

Exclusion Criteria:

* Prior treatment with an α-emitting molecular targeted therapeutic radioconjugate (prior treatment with radium-223 is permitted).
* Progression on PSMA-directed β-emitting radioconjugate prior to the administration of Cycle 3.
* Receipt of \> 6 cycles of PSMA-directed β-emitting therapeutic RC.
* History of another primary malignancy, with exceptions.
* Persistent toxicities (CTCAE Grade ≥ 2) caused by previous anticancer therapy, with exceptions.
* Spinal cord compression or brain metastases unless asymptomatic, stable, and not requiring steroids for at least 4 weeks prior to start of study intervention.
* Clinically significant ECG abnormalities, with exceptions.