As previously noted, NICE, the National Institute for Health and Clinical Excellence, does not furnish clinical approval of drugs. However, it does advise on the cost-effectiveness of a particular course of treatment or medication. As Dr Crippen notes NICE advice is a guideline and doctors are not obliged to follow it. However, PCTs all too often take NICE guidelines as law resulting in cases where patients take their PCT to court to gain access to a life-saving or extending treatment.
Dr Crippen points me to this and this discussing how NICE makes its decisions and how BigPharma influences it.