Many of the new drugs are trailed on patients, who decide that taking part in a trial may benefit their own health, and that of others.
I was prescribed a gold standard drug, which worked wonderfully for a year. I developed side effects, "rare, but well documented, in 1 in 100,000 patients". It took a year for the side effects to clear up, at which point I moved on to an older gold standard treatment, that had been in use for 20 years. 18 months on, it's working well, no side effects.
I wouldn't want to risk taking a new drug, that had not been approved by Nice. I don't have cancer though, maybe if I did, I'd feel differently.