TABLE A1.

Characteristics of the Pooled Trials

Clinical Trial	Study Population	PARPi Arm	Control Arm	Stratification Factors	HRR Genes	Diagnostic Assays	Imaging Interval
PROfound37	Second-line mCRPC	Olaparib	Abiraterone or enzalutamide	Previous taxane (yes v no) Measurable disease (yes v no)	ATM BRCA1 BRCA2 BRIP1 BARD1 CDK12 CHEK1 CHEK2 FANCL PALB2 PPP2R2A RAD51B RAD51C RAD51D RAD54L	FoundationOne CDx; FoundationOne Liquid CDx	CT/MRI and bone scan; every 8 weeks (±7 days) relative to the date of random assignment, until disease progression by BICR
PROpel20	First-line mCRPC	Olaparib plus abiraterone	Abiraterone plus placebo	Metastases (bone only v visceral v other) Docetaxel treatment at mCSPC stage (yes v no)	ATM BRCA1 BRCA2 BARD1 BRIP1 CDK12 CHEK1 CHEK2 FANCL PALB2 RAD51B RAD51C RAD51D RAD54L	FoundationOne CDx; FoundationOne Liquid CDx	CT/MRI and bone scan; every 8 weeks (±7 days) for the first 24 weeks, then every 12 weeks (±7 days) relative to the date of random assignment
TALAPRO-238	First-line mCRPC	Talazoparib plus enzalutamide	Enzalutamide plus placebo	HRR gene alteration status (HRRm v non-HRRm v unknown) Previous treatment with life-prolonging therapy (docetaxel or abiraterone, or both) in the castration-sensitive setting (yes v no)	ATM ATR BRCA1 BRCA2 CDK12 CHEK2 FANCA NBN MLH1 MRE11A PALB2 RAD51C	FoundationOne CDx; FoundationOne Liquid CDx	CT/MRI and bone scan; every 8 weeks through week 25 and then every 12 weeks until radiographic progression is determined by investigator (part 1) or by investigator and BICR (part 2)
MAGNITUDE39	First-line mCRPC	Niraparib plus abiraterone	Abiraterone plus placebo	Cohort 1 and 2:  Previous treatment with taxane-based chemotherapy (yes v no)  Previous treatment with novel antiandrogen therapy such as enzalutamide, apalutamide, and darolutamide (yes v no)  Previous treatment with abiraterone (yes v no). Cohort 1 only:  Gene alteration group (BRCAm v non-BRCA HRRm)	ATM BRCA1 BRCA2 BRIP1 CDK12 CHEK2 FANCA HDAC2 PALB2	FoundationOne CDx; Resolution Bioscience HRD plasma test; AmoyDx blood and tissue assays; Accredited local laboratory tests	CT/MRI and bone scan; at cycle 3 day 1, cycle 5 day 1, cycle 7 day 1, and then every 12 weeks until radiographic progression (a treatment cycle was defined as 28 days)
TRITON-240	≥Second-line mCRPC	Rucaparib	NA (single-arm trial)	NA (single-arm trial)	ATM BRCA1 BRCA2 BARD1 BRIP1 CDK12 CHEK2 FANCA NBN PALB2 RAD51 RAD51B RAD51C RAD51D RAD54L	Central testing by Foundation Medicine. Germline testing was performed by Color Genomics	CT and bone scan (MRI, X-ray, PET-CT, and ultrasound if required); every 8 weeks for up to 24 weeks, then every 12 weeks
TALAPRO-121	≥Second-line mCRPC	Talazoparib	NA (single-arm trial)	NA (single-arm trial)	ATM ATR BRCA1 BRCA2 CHEK2 FANCA MLH1 MRE11A NBN PALB2 RAD51C	FoundationOne CDx	CT/MRI and bone scan; every 8 weeks through week 25, then every 12 weeks thereafter

Abbreviations: BICR, blinded independent central review; CT, computed tomography; HRR, homologous recombination repair; mCRPC, metastatic castration-resistant prostate cancer; mCSPC, metastatic castration-sensitive prostate cancer; MRI, magnetic resonance imaging; NA, not available; PARPi, poly(ADP-ribose) polymerase inhibitor; PET, positron emission tomography.