How a Drug Grows Up The Four Phases of Drug Development

If your doctor has ever prescribed a new drug for you for anything at all, rest assured that even if you don’t know what it is or how it works, it has been through the ringer as far as testing is concerned. That doesn’t mean you shouldn’t still do all of the research you might be inclined to do, but it does mean that you can bet that the drug has been thoroughly tested. In fact, it has been put through the four phases of clinical drug development and if it has emerged ready for you to take, you can know that it must have passed the trials with flying colors.

There are four phases of clinical trials that new drugs have to go through in medical research studies. The phase 1 clinical trial, the phase 2 clinical trial which is a more in-depth version of phase 1, phase 3 which collects an enormous amount of data, and phase 4 which is mostly post-approval studies.

Phase 1 is a clinical study during which researchers will test a drug on a very small group of people for the first time. The test group will number anywhere from about 20-80 people and the tests will basically evaluate the drug’s safety and whether or not the drug will have side effects. It is a very general trial and since nothing has been done on humans before, would be one of the most important of the tests in clinical drug development.

Phase 2 is the phase in which the patients go up in number, ranging mostly from around 100-300 or so. It is during this phase that the new drug is being ushered out with a real concern for finding out how effective it might be. What is being studied here is the drug’s efficacy but also how it might be affecting a patient in adverse ways. The larger number of patients give the researchers a better indication of what kind of person is taking the drug and what their habits and lifestyle are like. This gives researchers more data to work with.

Phase 3 in a clinical drug development study sees this drug now being administered to a much larger group of people. Anywhere from 1,000 to 3,000 people will be given the test drug that has already gone through the first two phases of testing. What researchers are looking for at this point is confirmation of the drug’s effectiveness, whether or not there are significant side effects, how it might stand up alongside any standard of equivalent treatments already being used, and to collect any information that might improve the safety of the new drug.

By the time a new drug reaches the fourth phase in the clinical drug development process, it has largely been approved. These further tests are basically follow up tests that monitor patients and how they handle the drugs in long-term cases. The fourth phase has passed all of the watermarks set by a very high standard of excellence and can now be presented for FDA approval.