Study to Assess The Efficacy and Safety of a PARP Inhibitor For The Treatment of BRCA-positive Advanced Breast Cancer

The ORR is the percentage of participants whose best tumor response is either complete response (CR) or partial response (PR), according to the RECIST v1.0 criteria. The CR is defined as disappearance of all target lesions (TLs). The PR is defined as at least a 30% decrease in the sum of longest diameters (LD) taking as reference the baseline sum of LD. Percentage of participants with ORR is reported.

Duration of response is defined as the date of progression per RECIST criteria - the date when CR or PR [whichever is earliest] is confirmed + 1. The CR is defined as disappearance of all TLs. The PR is defined as at least a 30% decrease in the sum of LD taking as reference the baseline sum of LD. Duration of response was analyzed for those participants who had OR.

The CBR is defined as the percentage of participants with a RECIST tumor response of confirmed CR, PR or stable disease (SD) for ≥ 8 weeks +/- 1 week visit window. The CR is defined as disappearance of all TLs. The PR is defined as at least a 30% decrease in the sum of LD taking as reference the baseline sum of LD. Stable disease is neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD taking as references the smallest sum of LD since the treatment started.

The tumor size is defined as the sum of the longest diameters as measured among all target lesions. At each assessment, the percentage change in tumor size is defined as 100 × 1 - (sum of all target lesion diameters at visit/sum of all target lesion diameters at baseline).

PFS is defined as the time from first dose to the earlier date of radiologic progression (as per RECIST criteria) or death by any cause in the absence of objective progression. Those participants who were withdrawn from the study without disease progression were regarded as censored at their last evaluable RECIST assessment. Where participants had not progressed at the termination of the study, they were also regarded as censored at their last evaluable RECIST assessment. PFS was analyzed using Kaplan-Meier estimate.

ECOG performance status is used by researchers to assess how a participant's disease is progressing. The scores are: 0=Fully Active, able to carry out work without restrictions; 1=Restricted activity and able to carry out light work or sedentary nature; 2=capable of self-care but unable to carry out work activities; 3=Capable of only limited self-care, confined to bed or chair more than 50% of waking hours; 4=Completely Disabled, and totally confined to bed or chair; 5=Dead. Change in ECOG performance status was defined as improved (less than the baseline value), no change (same as at baseline), worsened (greater than the baseline value) or missing (score is missing or was not recorded at baseline). If no measurement was recorded at Cycle 1 Day 1, the change was calculated in relation to the last recorded ECOG value prior to Day 1.

An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. A serious adverse event (SAE) is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug.

Number of participants with clinically significant changes in vital signs are reported. Vital sign parameters included body temperature, blood pressure, and pulse rate.

Number of participants with at least 2-grade change from baseline to worst toxicity grade in clinical laboratory parameters are reported. Laboratory parameters included hematology, clinical chemistry, and urinalysis.