This is a randomized phase II study to evaluate the disease control rate (DCR) of patients with metastatic or locally advanced METHYLATED 06-methylguanine-DNA methyltransferase (MGMT) with triple-negative breast cancer (TNBC) treated with Temozolomide ± Olaparib. Patients will be randomized 1:1 to Treatment Arm 1 (temozolomide treatment) or Arm 2 (temozolomide plus olaparib treatment).
Female or male patients with triple negative breast cancer confirmed by pathology of the primary tumour or metastatic biopsy sample. Estrogen receptor (ER) and progesterone receptor (PgR) must be ≤2 Allred score by Immunohistochemistry (IHC); human epidermal growth factor receptor 2 (HER2) 0 or 1+ by IHC, or 2+ with confirmed negativity by in situ hybridization (ISH) assay.
Available Formalin-Fixed Paraffin-Embedded (FFPE) tumour tissue. If archival tissue is not available, the participant will have the option to provide a fresh tumour tissue specimen from a newly obtained biopsy. If archival and fresh tissue are not available, the participants will be excluded.
MGMT promoter methylated by clinical assay.
Prior exposure to anthracyclines and taxanes in adjuvant/neoadjuvant and/or metastatic setting.
Patients who have received chemotherapy within 4 weeks or radiotherapy to a non-target site within 2 weeks prior to entering the study or who have not recovered from adverse events from prior anti-cancer therapy (residual toxicities > Grade 1) with the exception of alopecia.
Patients who are receiving any other investigational agents within 3 weeks of signing the main informed consent form.
Patients with a history of other malignancies, except: adequately treated non-melanoma skin cancer, curatively treated in-situ cancer of the cervix, or other solid tumours curatively treated with no evidence of disease for ≥ 5 years.
Patients with psychiatric illness/social situations/substance abuse that would limit compliance with study requirements.