Drug Discovery
From Molecule to Marketplace
It takes about 12-15 years for a drug to make the journey from the initial discovery of a molecule to a bottle of medicine in your medicine cabinet. Approximately 6-9 of those years are spent in the basic science laboratory where a team of chemists and biologists study the brand new chemical compound in test tubes and in animals to determine if it is safe and effective enough to be tested in humans. This is called pre-clinical testing. When pre-clinical testing is finished, the company sends the data to the U.S. Food and Drug Administration (FDA) in what is termed an Investigational New Drug Application (IND). The next 6 or so years are spent performing clinical trials in humans to generate enough data for the FDA to make an informed decision on whether to approve the new drug for use in humans.
Clinical studies in humans are generally performed in three phases.
- Phase I studies are performed in 100 to 200 healthy volunteers to determine if the drug is safe, what dose is needed to elicit an effect, and how the body metabolizes and eliminates the drug. This phase lasts about 1 to 2 years.
- Phase II studies collect initial data on the efficacy of the drug in a small number of patients with the disease that the drug was designed to treat. This phase lasts about 2 years.
- Phase III studies are the large clinical trials that collect data on the efficacy and safety of the drug in 2,000 to 4,000 patients. This phase lasts about 3 to 4 years.
When the Phase III studies are finished, the company sends the data to the FDA in what is called a New Drug Application (NDA). The FDA generally takes 1 year to review the studies before they approve or disapprove the use of the drug in humans. Occasionally the FDA will ask that further studies be done before they can decide to approve or disapprove.
Phase IV studies may be performed after the drug has been approved and on the market (post-marketing). These studies provide additional information about the safety and effectiveness of the drug or about additional ways that the drug can be used. Phase IV studies that are performed to observe the outcome of long-term use of a drug are also known as “outcome” studies. For example, it was believed that long term use of a cholesterol lowering drug would reduce deaths due to cardiovascular disease, increasing the life span of patients. However, it was important to actually perform these large, long, expensive “outcome” studies to determine if that belief, or hypothesis, was true.
Safety is very carefully monitored throughout the entire process; from the pre-clinical testing through phase IV studies and continuously during the whole time a medicine is on the market.