2 The technology
2.1 Abiraterone acetate (Zytiga, Janssen) is a selective inhibitor of androgen biosynthesis which is taken orally. It irreversibly blocks cytochrome P17 (an enzyme involved in the production of testosterone), thereby stopping androgen synthesis in the adrenal glands, prostate tissue and the prostatic tumour. Abiraterone has a UK marketing authorisation for use 'with prednisone or prednisolone for the treatment of metastatic castration resistant prostate cancer in adult men whose disease has progressed on or after a docetaxel‑based chemotherapy regimen'. For prostate cancer that was previously considered 'hormone refractory,' the term 'castration resistant' is now used because the cancer still depends on hormones to activate androgen receptors, but no longer responds to traditional androgen‑reducing treatments.
2.2 The summary of product characteristics lists the following common adverse reactions to abiraterone: peripheral oedema, hypokalaemia, hypertension and urinary tract infection. For full details of adverse reactions and contraindications, see the summary of product characteristics.
2.3 The cost of abiraterone is £2,930 for 120 tablets (excluding VAT; British national formulary [BNF] 63, March 2012). Abiraterone is administered as a single dose of 1 g per day, taken as four 250‑mg tablets. The company has agreed a commercial access arrangement with NHS England, the details of which are confidential. This commercial access arrangement was agreed in July 2016, after guidance publication. It presents a change to the pricing arrangement that was considered during development of this guidance. The pricing arrangement considered during guidance development was that the manufacturer of abiraterone (Janssen) had agreed a patient access scheme with the Department of Health. This involved a single confidential discount being applied to the list price of abiraterone. The Department of Health considered that this patient access scheme did not constitute an excessive administrative burden on the NHS. The commercial access arrangement agreed in July 2016 replaces the PAS and therefore the PAS no longer applies.