Study to Compare the Efficacy and Safety of Olaparib When Given in Combination With Carboplatin and Paclitaxel, Compared With Carboplatin and Paclitaxel in Patients With Advanced Ovarian Cancer

To compare the efficacy of olaparib in combination with paclitaxel and carboplatin (AUC4) when compared with carboplatin (AUC6) and paclitaxel alone in patients with advanced ovarian cancer.

Inclusion Criteria: * Diagnosed with serous ovarian cancer * Patients who have received no more than 3 previous platinum containing treatments and were progression free for at least 6 months following the end of the last platinum treatment * At least one lesion that is suitable for accurate repeated measurements Exclusion Criteria: * Patients receiving any systemic anticancer chemotherapy, radiotherapy (except palliative) within two weeks from the last dose prior to study treatment * Hypersensitivity to pre medications required for treatment with paclitaxel/carboplatin