Phase I/II Study of AZD2281 Given in Combination With Paclitaxel in Metastatic Triple Negative Breast Cancer

Inclusion Criteria: * patients with histologically or cytologically diagnosed metastatic triple negative breast cancer (Oestrogen, progesterone and HER2 negative adenocarcinoma of the breast) * Patients must have normal organ and bone marrow function, ECOG performance status of no more than 2 * Formalin fixed, paraffin embedded tumour sample from the primary or recurrent cancer must be available for central testing. Exclusion Criteria: * Any chemotherapy, radiotherapy (except for palliative reasons) or investigational product, within 2 weeks from the last dose prior to study entry (or longer period, depending on the agent used) * Major surgery within 4 weeks of starting the study, and must have recovered from any effects of major surgery * Patients requiring treatment with the following:certain antibiotic drugs, St.John's Wort, carbamazepine, phenobarbitone, phenytoin, and certain protease inhibitors/ non-nucleoside reverse transcriptase inhibitors used as components of HIV/AIDS treatment, * Patients with second primary cancer; 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 at least 5 years.