Medical R&D
Medical research and development (R&D) is undoubtedly an unpredictable, lengthy and expensive process. There are many entities involved, including universities, non-governmental organizations, governmental organizations, and pharmaceutical companies.
Basic research
Medical R&D begins with basic research on the disease itself. Basic research seeks to understand the biology of a specific disease, down to the molecular level. This research is unpredictable and potentially never-ending, due to the immense complexity of the human body and disease processes. Any given scientist may spend decades on research with no obvious direct impact on health care; but with many people working together, useful knowledge is gradually assembled.
Once a sufficient level of understanding of the disease is reached, screening of potential compounds that would affect the disease may begin. Through computer simulation or manual trial-and-error, scientists search through extensive compound libraries and to seek those that might affect the biology, and therefore the outcome, of the disease, and that might feasibly and safely be given to people.
Preclinical trials
The most promising compounds then proceed to preclinical trials. Further tests are carried out in test tubes (in vitro), as well as in animals (in vivo). The goal is to further determine whether the drug might really be effective, what doses might be safe, and what negative side effects might occur.
Clinical trials
If the drug still appears to be safe and effective, testers then request regulatory approval to conduct clinical trials: that is, trials in humans.
In phase I, an initial assessment of safety, a small study group of about 100 healthy subjects are issued the compound. Doses are administered in an increasingly concentrated fashion to determine any ill effects on healthy subjects.
In phase II, an initial assessment of efficacy, 100 to 500 subjects are enlisted who actually have the disease of interest. Patients are carefully monitored to determine the drug's impact on the true disease.
In phase III, long-term effects are assessed in 1000 to 4000 patients. This is the longest stage.
Marketing and surveillance
Finally, the tester submits all the evidence gathered so far to regulatory authorities. If approved, the drug is now allowed to be marketed. To be approved a drug must be useful to treat a given disease, and cause minimal harm. In addition, its labelling must be accurate and non-deceiving, and the production processes must be reliable.
Once marketing begins, the drug must simultaneously go through phase IV, in which the drug, now that it is being used in practice, is monitored for rarer or very long-term side effects.
