The primary aim of study is to gain an initial assessment of safety and tolerability of AZD3514 in Japanese patients together with assessing Pharmacokinetics (PK) and gaining a preliminary assessment of anti-tumour action. In this study, AZD3514 will be administered to Japanese patients with metastatic castration resistant prostate cancer.

Inclusion Criteria:

• Males aged 20 years or older.
• Histologically or Cytologically proven diagnosis of prostate cancer for which no standard therapy is currently considered appropriate
• Documented evidence of metastatic prostate cancer
• Serum testosterone concentration ≤50 ng/dL
• World Health Organisation (WHO) performance status 0 to 1 with no deterioration over the previous 2 weeks and minimum life expectancy of 12 weeks

Exclusion Criteria:

• History of hypersensitivity to active or inactive excipients of AZD3514 or drugs with a similar chemical structure or class to AZD3514
• Refractory nausea and vomiting, chronic gastrointestinal diseases, inability to swallow the formulated product or previous significant bowel resection that would preclude adequate absorption of AZD3514
• Inadequate bone marrow reserve or organ function
• Concurrent or recent treatment with certain medications or medical procedures
• Any medically important factors identified from electrocardiogram (ECG) measurements