A Study of Rucaparib in Patients With Metastatic Castration-resistant Prostate Cancer and Homologous Recombination Gene Deficiency

The primary efficacy endpoint is confirmed radiographic ORR by central IRR. ORR is defined as the percentage of patients with a confirmed CR (complete response) or PR (partial response) by mRECIST (modified Response Evaluation Criteria in Solid Tumors) v1.1/PCWG3 (Prostate Cancer Working Group 3) criteria. The confirmed response is defined as a CR or PR on subsequent tumor assessment at least 28 days after first response documentation in the absence of confirmed progression in bone. CR is disappearance of all target and non-target lesions; any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR is at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: IRR Efficacy Population - The IRR efficacy population is defined by measurable disease status at baseline using modified RECIST Version 1.1 criteria per independent radiology review.

A secondary efficacy endpoint is Clinical Benefit Rate (CBR) assessed by IRR. CBR is defined as the number of patients without radiographic progression (defined by modified RECIST Version 1.1/ PCWG3 criteria) who were continuing with study drug treatment through the given time interval divided by the number of patients who had the given amount of follow-up. Clinical benefit rates are summarized at 6 and 12 months.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: All patients

A secondary efficacy endpoint is Clinical Benefit Rate (CBR) assessed by Investigator. CBR is defined as the number of patients without radiographic progression (defined by modified RECIST Version 1.1/ PCWG3 criteria) who were continuing with study drug treatment through the given time interval divided by the number of patients who had the given amount of follow-up. Clinical benefit rates are summarized at 6 and 12 months.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: All patients

A supportive efficacy endpoint is confirmed radiographic ORR by INV. ORR is defined as the percentage of patients with a confirmed CR (complete response) or PR (partial response) by mRECIST (modified Response Evaluation Criteria in Solid Tumors) v1.1/PCWG3 (Prostate Cancer Working Group 3) criteria. The confirmed response is defined as a CR or PR on subsequent tumor assessment at least 28 days after first response documentation in the absence of confirmed progression in bone. CR is disappearance of all target and non-target lesions; any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR is at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: Investigator Efficacy Population - The Investigator efficacy population is defined by measurable disease status at baseline using modified RECIST Version 1.1 criteria per the investigator (INV).

A secondary endpoint is confirmed PSA (prostate-specific antigen) response (≥ 50% reduction) as assessed by local laboratory. Confirmed PSA response is analyzed for all patients who had PSA value at baseline and is defined as the percentage of patients having 2 consecutive PSA values (at least 3 weeks apart) that are at least 50% lower than baseline and that occur prior to PSA progression. PSA progression is defined as a ≥ 25% increase and absolute increase of ≥ 2 ng/mL above the nadir in PSA.

Time frame: PSA assessments were done at baseline, Week 5, Week 9, every 4 weeks thereafter, and at Treatment Discontinuation. Total follow-up was up to approximately 39 months.

Population: All patients who had a PSA value at baseline.

A secondary endpoint is confirmed PSA (prostate-specific antigen) response (≥ 90% reduction) as assessed by local laboratory. Confirmed PSA response is analyzed for all patients who had PSA value at baseline and is defined as the percentage of patients having 2 consecutive PSA values (at least 3 weeks apart) that are at least 90% lower than baseline and that occur prior to PSA progression. PSA progression is defined as a ≥ 25% increase and absolute increase of ≥ 2 ng/mL above the nadir in PSA.

Time frame: PSA assessments were done at baseline, Week 5, Week 9, every 4 weeks thereafter, and at Treatment Discontinuation. Total follow-up was up to approximately 39 months.

Population: All patients who had a PSA value at baseline.

A secondary efficacy endpoint is DOR by central IRR. The DOR is defined as the time from the date that a confirmed response per modified RECIST Version 1.1/PCWG3 is first reported to the time that progressive disease (PD) is first documented. Progressive disease is defined using RECIST v1.1, as at least a 20% increase in the sum of the diameters of target lesions, or an unequivocal increase in non-target lesions, or the appearance of new lesions. PCWG3 criteria is used to document evidence of disease progression in bone lesions.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: Patients with a confirmed response in the IRR Efficacy Population. The IRR efficacy population is defined by measurable disease status at baseline using modified RECIST Version 1.1 criteria per independent radiology review. Note, there were no patients with confirmed response by IRR in the ATM, CDK12 and CHEK2 arms.

A secondary efficacy endpoint is DOR as assessed by the investigator. The DOR is defined as the time from the date that a confirmed response per modified RECIST Version 1.1/PCWG3 is first reported to the time that progressive disease (PD) is first documented. Progressive disease is defined using RECIST v1.1, as at least a 20% increase in the sum of the diameters of target lesions, or an unequivocal increase in non-target lesions, or the appearance of new lesions. PCWG3 criteria is used to document evidence of disease progression in bone lesions.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: Patients with a confirmed response in the Investigator Efficacy Population. The Investigator efficacy population is defined by measurable disease status at baseline using modified RECIST Version 1.1 criteria per the investigator. Note, there were no patients with confirmed response by investigator in the CDK12 arm.

A secondary efficacy endpoint is Overall Survival (OS). OS is defined as the date from first dose of rucaparib to the date of death due to any cause, +1 day.

Time frame: From date of first dose until event, loss to follow-up, withdrawal of consent, or study closure: an overall median of approximately 33.1 months

Population: Safety Population - The safety population consists of all patients who received at least 1 dose of protocol-specified treatment.

A secondary efficacy endpoint is Radiologic Progression-free Survival (rPFS) assessed by IRR. rPFS is defined as the time from first dose of rucaparib to the date of first objective evidence of radiographic progression (soft tissue or bone lesion) or death due to any cause, whichever occurs first, plus 1 day. Radiographic disease progression includes confirmed bone disease progression and soft tissue disease progression adjudicated by IRR using the PCWG3 guidelines for bone disease and modified RECIST Version 1.1 for soft tissue disease.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: All patients

A secondary efficacy endpoint is Radiologic Progression-free Survival (rPFS) assessed by Investigator. rPFS is defined as the time from first dose of rucaparib to the date of first objective evidence of radiographic progression (soft tissue or bone lesion) or death due to any cause, whichever occurs first, plus 1 day. Radiographic disease progression includes confirmed bone disease progression and soft tissue disease progression using the PCWG3 guidelines for bone disease and modified RECIST Version 1.1 for soft tissue disease.

Time frame: Assessments every 8 weeks from study day 1 for the first 24 weeks, and then every 12 weeks until disease progression, death, or initiation of subsequent treatment. Total follow-up was up to approximately 3 years.

Population: All patients

Trough (Cmin) concentrations of rucaparib are summarized for all patients with at least one PK sample collected. The absolute values of rucaparib plasma concentration at each time point are presented by gene.

Time frame: Participants were assessed at Study Day 29, Day 57, Day 85 and Day 113

Population: Safety population with at least one PK sample collected. The safety population consists of all patients who received at least 1 dose of protocol-specified treatment.

A secondary efficacy endpoint is time to PSA progession. Time to PSA progression is defined as the time from first dose of rucaparib to the date that a ≥ 25% increase and absolute increase of ≥ 2 ng/mL above the nadir (or baseline if there was no PSA decline after baseline) in PSA was measured, plus 1 day. The increase must be confirmed by a second consecutive assessment conducted at least 3 weeks later (unless the PSA progression occurred at the last recorded PSA assessment). If confirmed, the date used for time of PSA progression is the earlier of the 2 PSA dates.

Time frame: PSA assessments were done at baseline, Week 5, Week 9, every 4 weeks thereafter, and at Treatment Discontinuation. Total follow-up was up to approximately 39 months.

Population: All patients who had a PSA value at baseline.