Have you considered asking your oncologist to write you a private prescription? You would pay the full cost of the drug. The following is taken from the NICE website
"Enzalutamide costs £2734.67 for 1 pack of 112 40‑mg capsules, (excluding VAT; 'British national formulary' [BNF] website accessed March 2014). Assuming a daily dose of 160 mg and a mean length of treatment of 8.5 months, the manufacturer estimated that the average cost of treatment with enzalutamide, based on the list price, is £25,269."
Not very encouraging to say the least.