To Study Clinical Effectiveness and Safety of Olaparib Monotherapy in Metastatic Breast Cancer Patients.

The study is a phase IIIb, multicenter, single-arm, open-label study designed to evaluate the clinical effectiveness in a real-world setting of olaparib monotherapy in patients with confirmed germline or somatic breast cancer susceptibility gene (gBRCA1/2 or sBRCA1/2) mutations. This study will generate additional data to support other olaparib studies, which may help inform and guide clinical practice. Physician defined the progression-free survival (PFS) for gBRCAm patients is the primary outcome measure. Based on the prevalence of gBRCA1/2 mutations, it is estimated that up to 1400 patients may require screening in order to identify 250 gBRCA mutated patients and 20 sBRCA mutated patients. Patients will be administered two olaparib 150mg tablets in morning and evening of every day after a light meal. Dose reductions may be required for olaparib treatment related toxicities. Patients should continue to receive study treatment until documented physician-defined disease progression as assessed by the investigator (gBRCA mutated patients), RECIST1.1 disease progression (sBRCA mutated patients) or unacceptable toxicity, or for as long as they do not meet any other discontinuation criteria. A positive benefit/risk profile is expected and no ethical issues are identified from exposing patients to olaparib within the planned clinical study.