Sipuleucel-T is a personalised immunotherapy vaccine that was developed for the treatment of metastatic castrate-resistant prostate cancer (mCRPC). The principle underpinning the action of Sipuleucel-T is the induction of a host immunological response towards prostate cancer cells. This is achieved by priming an individual’s immune cells to recognise tumour-associated prostate acid phosphatase on malignant cells, stimulating an adaptive immune response to target and eliminate cancerous cells. Generally it is well tolerated with most adverse effects being mild and self-limiting. Trials have shown an overall survival benefit of approximately 4 months in men with metastatic castrate-resistant prostate cancer. It is not currently recommended by NICE in the United Kingdom.