Saruparib in Combination With Physician's Choice of ARPI in Patients With mHSPC Previously Treated With Docetaxel or 177Lu-PSMA Therapy Without Disease Progression and PSA ≥ 0.2 ng/mL (EvoPAR-PR05)

Overall Survival (OS)

OS is defined as the time from the date of randomization until death due to any cause.

Time frame: Up to approximately 80 months

Radiographic progression-free survival (rPFS)

Radiographic PFS (rPFS) is the primary endpoint of this study, defined as the time from randomization to radiographic progression, as assessed by the investigator per RECIST 1.1 (soft tissue) and/or PCWG3 criteria (bone), or death due to any cause.

Time frame: Up to approximately 56 months

Time to Second Progression or Death (PFS2)

PFS2 is defined as the time from randomization to the earliest progression (defined as radiographic progression, clinical progression, or PSA progression) after initiation of first subsequent treatment following the initial investigator-assessed progression or death (ie, date of PFS2 event or censoring - date of randomization + 1).

Time frame: Up to approximately 56 months

Time to First Subsequent Therapy or Death (TFST)

TFST is defined as the time from randomization to the start date of the first subsequent anticancer therapy after discontinuation of randomized treatment, or death due to any cause (ie, date of first subsequent cancer therapy or death - date of randomization + 1).

Time frame: Up to approximately 56 months

Symptomatic Skeletal Event-free Survival (SSE-FS)

SSE-FS is defined as the time from the date of randomization to the earliest of the following: * Use of radiation therapy to prevent or relieve skeletal symptoms. * Occurrence of new symptomatic pathological bone fractures (vertebral or non-vertebral). Radiographic documentation is required. A pathological fracture, as determined by investigator, is defined as associated with low or no trauma and deemed to have occurred at a site of bone metastasis. * Occurrence of spinal cord compression. Radiographic documentation is required. * Orthopedic surgical intervention for bone metastasis. * Death due to any cause.

Time frame: Up to approximately 56 months

Time to Castration Resistance (TTCR)

TTCR is defined as the time from randomization to the first castration-resistant event (radiographic disease progression, PSA progression per PCWG3, or SSE, whichever occurs first, with castrate levels of testosterone below 50 ng/dL).

Time frame: Up to approximately 56 months

Time to PSA progression

Time to PSA progression, defined as the time from randomization to PSA progression per PCWG3 criteria.

Time frame: Up to approximately 56 months

Time to deterioration in physical function (TTDPF)

TTDPF is defined as the time from randomization to deterioration in PROMIS SF-PF scores.

Time frame: Up to approximately 56 months

Time to pain progression (TTPP)

TTPP is defined as the time from randomization to clinically meaningful pain progression based on a 2-point increase from baseline in the BPI-SF Item 3 'worst pain in 24 hours' score and/or initiation of/increase in opioid analgesic use.

Time frame: Up to approximately 56 months

Brief Pain Inventory - Short Form (BPI-SF)

Change from baseline in BPI-SF worst pain score, pain severity and interference domain scores.

Time frame: Up to approximately 56 months

Time to deterioration in urinary symptoms (TTDUS)

TTDUS is defined as the time from randomization to deterioration in the EORTC QLQ-PR25(US) subscale scores.

Time frame: Up to approximately 56 months

Plasma concentrations of AZD5305

To assess PK of AZD5305 in plasma

Time frame: Day 1 of Cycle 1, Cycle 2 and Cycle 3 (each cycle is of 28 days)