The process of creating new medicines is complex, time-consuming, and costly. Moving a potential therapy from concept to market can take between 10 and 15 years and cost developers as much as $1 billion. Indeed, industry also bears the cost of failure: For every drug that ultimately receives approval from the U.S. Food and Drug Administration, some 5,000 to 10,000 compounds don't make it through the process.1
The early laboratory research that constitutes drug discovery is the first step in a rigorous development process. During this stage, scientists search for or create compounds that may eventually become approved medicines. These initial molecules then progress to preclinical testing—extensive laboratory and animal experiments that will determine their safety for testing in humans. Drug developers must show FDA the results of these studies and describe how they plan to test the drug candidate in clinical trials. The agency bears the ultimate responsibility for deciding whether a compound is reasonably safe to move forward with testing in humans. From there, a drug will undergo progressive phases of clinical trials to gather the evidence of safety and efficacy needed to gain FDA approval. Drug candidates can be disqualified at any step of the process if they are found to be unsafe or ineffective, or they may be abandoned for business reasons.
The drug development process is meant to ensure that patients receive safe and effective medicine. However, pharmaceutical development is not a one-size-fits-all proposition. Testing and evaluation of any drug must take into account the benefits and risks for the patients the drug is meant to treat. This is particularly true when developing antibiotics for limited populations of patients with serious bacterial infections, who have few, if any, treatment options.
1Pharmaceutical Research and Manufacturers of America, “Drug Discovery and Development: Understanding the Process,” accessed Jan. 17, 2014, http://www.innovation.org/drug_discovery/objects/pdf/RD_Brochure.pdf.
The Drug Discovery and Development Process
|Preclinical||Laboratory and animal studies are used to determine whether a drug candidate is safe enough to test in people. Drug developers must file an investigational New Drug application with the Food and Drug Administration outlining the results of preclinical studies before clinical trials can begin.|
|Phase 1||Initial testing is conducted in a small number of healthy volunteers (20 to 80) to determine if the drug is reasonably safe. During this phase, developers examine how the drug is absorbed and metabolized.|
|Phase 2||Testing evaluates the drug candidate's effectiveness and safety in a group of patients (generally 30 to 300) who have the condition the drug is meant to treat. Drug developers examine the side effects and potential risks of the drug and the initial indications of its effectiveness. Phase 2 studies provide information on the optimal dose for the drug and how it should be administered.|
|Phase 3||The drug is tested in a large group (often 1,000 or more people) to gather evidence about the safety, effectiveness, benefits, and risks of the drug. Test subjects have the condition the drug is meant to treat. Phase 3 studies provide key information used by FDA in deciding whether to approve a drug for use.|
|New Drug Application||A drug developer requests approval to market a drug to patients by submitting a New Drug application to FDA. This application contains the results of all animal and human studies of the drug, as well as information on its manufacturing. The agency reviews the application and decides whether the drug can be approved or needs additional testing.|
|Phase 4 (Post-Marketing Studies)||FDA often requires sponsors to monitor the risks and benefits of a drug after it has been approved and made available to the public. In some cases, post-marketing studies focus on a subgroup of the general population that could not be adequately evaluated during clinical testing, such as pregnant women.|
National Institutes of Health, “NIH Clinical Research Trials and You,” accessed Jan. 17, 2014, http://www.nih.gov/health/clinicaltrials/basics.htm.
U.S. Food and Drug Administration, “FDA Drug Approval Process Infographic,” accessed Jan. 17, 2014, http://www.fda.gov/Drugs/ResourcesForYou/Consumers/ucm295473.htm.
U.S. Food and Drug Administration, “The FDA's Drug Review Process: Ensuring Drugs Are Safe and Effective,” accessed Jan. 17, 2014, http://www.fda.gov/drugs/resourcesforyou/consumers/ucm143534.htm.