Yeah there are a lot of phases, but each phase takes a while. (Though the first couple phases, which are mostly about ensuring that the drug isn't poisonous, don't take too long.) Clinical work has to move at the speed of biology, which is very slow compared to computers. Skin cells, which have a really short life cycle, divide every 15 days. For a disease like cancer, if even a handful of cancerous cells hasn't been destroyed, you could experience a relapse--but it would take a while, perhaps even years, for the cancer to build back up to detectable levels. If your disease takes years to confirm that it's gone, the clinical trial is going to take years to confirm that it works. It really sucks, but that's just how biology works.
Exactly, which was my point to the original parent. =)
Biology is slow, so effective and scientifically accurate trials are slow. These slow trials are required because of regulations for health and safety reasons, which means time to market is slow for drugs.
Which means complaining about the 25 year time to market (the original parent's comment) is really the same as complaining about regulations. Drop the regulations and companies are no longer required to do scientifically accurate/responsible studies, which means faster to-market times (and less safe drugs).
