Efficacy and Safety of BGB-290 in the Treatment of Metastatic HER2-Negative Breast Cancer Patients With BRCA Mutation in China

Inclusion Criteria: 1. Confirmed deleterious or suspected deleterious germline BRCA1 or BRCA2 mutation 2. Locally advanced or metastatic breast cancer despite standard therapy and the following: 1. Histologically or cytologically confirmed HER2(-) breast cancer (TNBC or estrogen receptor-positive and/or PR+) 2. ≤ 2 prior lines of chemotherapy in advanced or metastatic setting 3. Prior platinum therapy allowed as long as no disease progression while on treatment, or if given in neoadjuvant/adjuvant setting with ≥ 6 months from last platinum to relapse 4. Prior therapy with an anthracycline and/or a taxane in neoadjuvant/adjuvant or metastatic setting 5. Archival tumor tissues will be collected from all patients, if available 6. For HR(+)/HER2(-) breast cancer only: patients must have received and progressed on at least one endocrine therapy either in adjuvant or metastatic setting, or have disease that the treating physician believes to be inappropriate for endocrine therapy 3. Measurable disease as defined per RECIST, version 1.1 4. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1 5. Adequate hematologic and organ function Exclusion Criteria: 1. Unresolved acute effects of prior therapy of ≥ Grade 2 2. Prior treatment with a poly\[ADP-ribose\] polymerase (PARP) inhibitor 3. Chemotherapy, radiotherapy, biologic therapy, immunotherapy, investigational agent, anticancer Chinese medicine, or anticancer herbal remedies ≤ 14 days (or ≤ 5 half lives, if applicable, whichever is shorter) prior to Day 1 of Cycle 1 4. Major surgical procedure, open biopsy, or significant traumatic injury ≤ 14 days prior to Day 1 of Cycle 1, or anticipation of need for major surgical procedure during the course of the study 5. Diagnosis of myelodysplastic syndrome (MDS) 6. Other diagnosis of malignancy 7. Untreated and/or active brain metastases. 8. Active infection requiring systemic treatment, active viral hepatitis, or active tuberculosis 9. Clinically significant cardiovascular disease 10. Pregnancy or nursing 11. Known history of intolerance to the excipients of the BGB-290 capsule