I used to work for a research scientist at Vanderbilt University Medical Center. I was an administrator so I don't have an opinion on the scientific end of things. But I did learn a bit about the protocol for drug testing.
Typically a drug is tested in this sequence:
Preclinical: tested on animals
Clinical Trials: the drug is tested on small numbers of patients. These Clinical trials are broken down into Phase I, II and III which occur in sequence, not simultaneously.
I don't know what the difference is between Phases I, II and III but there seems to be a refinement in the amounts of and timetable by which the drug is administered. For example, orally, injected, daily, weekly, monthly. This is important because when it comes time to submit the drug to the FDA, the Drug Company must submit data for the exact dosages and timetables that doctors will be using when the drug is approved. Also, the drug might be found to be more effective on women, or one men, etc. It's not just the drug that is approved but also the way in which it is administered!
If the Phase I trial goes very well, they sometimes skip to the Phase III trial directly. Usually the drug company chooses several hospitals to simulaneously sponsor Phase III trials.
After Phase III, the drug is usually ready to be submitted to the FDA for approval for widespread use.
I don't know how much time elapses between Phase I and Phase II and Phase III clinical trials but I imagine there is a delay as the data is analyzed and a new protocol established for the next Phase of clinical trials.
Hope this helps.
Sanjay |
