How are medicine developed?
Medicines development, often used interchangeably with drug development, refers to the scientific and regulatory processes involved in bringing a new medicine to the market. Medicine development is costly and time-consuming. It takes an average of 10-15 years and more than US$2 billion before it can reach the pharmacy shelf.
It starts from the pre-discovery phase during which researchers try to understand the mechanisms underlying diseases and propose possible biological targets for treating them. In the discovery phase, scientists look for potential small molecules or biologics, the “leads”, that will modulate this target and possess a therapeutic effect. Scientists then chemically modify the lead to further improve the lead's properties and therapeutic effects.
The resulting lead, now an optimised drug candidate, then moves to pre-clinical testing for studying how effective (the efficacy) and safe it is using different testing approaches. These testing approaches include in vitro testing (in a controlled environment outside a living organism like a petri dish) and in vivo testing (in a living organism) before it can be tested on humans. The results from pre-clinical studies provide information for a safe and efficacious product dosage to be used in clinical trials.
The drug candidate is next tested in clinical trials in humans if its clinical trial application is approved by regulatory authorities based on pre-clinical data, and the clinical research protocol. Clinical trials are an important part of medicine development, with the purpose to evaluate the active ingredient by finding the appropriate dosage range and identifying the side effects. Clinical trials are generally carried out in three phases, phase I, II and III. In an ideal scenario, the active ingredient would first be tested in phase 1 trials for general safety on a small group of healthy volunteers, followed by phase II trials on a larger group including patients, further followed by phase III trials for confirmatory studies on a large group of subjects.