 The planned dose escalation will start with cohort 1, where patients will receive carboplatin AUC5 on day 1 of cycle 1, and will start dosing with olaparib tablets at the dose of 50 mg twice daily bd on day 4 until day 19 of cycle 1 inclusive a total of 16 days per cycle. Patients will receive carboplatin on day 1 of each 3 weeks cycle in combination with olaparib for a total of 4 cycles. Provided that there are no safety concerns after assessment of 6 evaluable patients in the first cohort, patients in subsequent cohorts may be dosed following Safety Review Committee SRC approval. Dose escalation scheme may be adjusted during the study on the basis of emerging safety, efficacy and pharmacokinetic data. Those patients in Part A who tolerate the combination up to and including cycle 4 may remain on treatment, either continuing with the combination, with carboplatin alone at the same AUC or with olaparib alone at the dose of 300 mg bd, if in the opinion of the treating Investigator, a patient is deemed to be deriving clinical benefit from treatment. In these cases, a patient may remain on treatment until progression, unacceptable toxicity or until other discontinuation criteria are met. Beyond cycle 4, patients will undergo assessments in line with the clinical protocol. Once the maximum tolerated dose MTD andor recommended dose RD has been defined in Part A, a dose expansion phase, Part B will begin and this will include up to 21 patients with HER2 negative breast cancer, with a deleterious or suspected deleterious germlineBRCA12 gBRCA12 mutation, who are deemed eligible for neoadjuvant therapy. 