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The FDA Process: How Drugs Are Approved and Monitored

Dr. Mario Trucillo

Last updated: November 22, 2016 3:15 pm

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Every day, millions of people take medicine to help them fight illness, manage pain and hopefully live better lives. However, most people do not know the process by which these drugs become available to them. This overview is designed to help you better understand the FDA’s drug approval process and its importance for helping to keep the public safe from risky and untested “cures.”

Early Days

In 1906, the Bureau of Chemistry, which later became the U.S. Food and Drug Administration (FDA), began regulating drugs after the passage of the Pure Food and Drugs Act. 1 It wasn’t until 1938, however, that a new law required manufacturers to submit evidence of a drug’s safety to the FDA before going on the market. This was the first formal FDA approval process, a regulatory procedure that later became known as a New Drug Application (NDA). 2

Since then, the process has gone through many changes and is still evolving. Each year the FDA reviews hundreds of NDAs through its Center for Drug Evaluation and Research (CDER), which is responsible for ensuring that drugs marketed in the U.S. are safe and effective. 3 CDER monitors each new drug from the lab to the marketplace and evaluates it through a long, rigorous process. 4

1. Pre-Clinical Discovery and Screening

Once a drug company (“sponsor”) develops a new drug, and before the FDA will approve the drug for sale, the company must first experiment using both test tubes (in vitro) and laboratory animals (in vivo) to determine the safety and efficacy of the drug. Generally, the tests will attempt to determine how toxic the drug may be, as well as any side effects and metabolic concerns. Although the FDA has issued broad guidelines for companies and laboratories to follow, each clinical trial is different, depending on the specific characteristics of the drug. 5

After gathering data in these preliminary studies, the company’s next step is to submit an Investigational New Drug (IND) application to the FDA. The IND application provides details about initial findings, along with in-depth details about composition, an account of the manufacturing process, and proposals for testing the drug in humans. If the FDA determines that it is reasonably safe to move forward with human testing, the clinical trial process may begin.

2.  Clinical Studies and Trials

Drug studies, often called clinical trials, can start after an IND application is approved and the proposed study details are approved by an the institutional review board (IRB), a panel of experts at the facilities where the drug will be tested. Each IRB evaluates the study guidelines, including all aspects of the clinical trial and intended testing procedures, and either approves or denies the study based on that assessment.

The clinical trial process is frequently broken up into multiple phases that examine:

  • Safety
  • Frequent side effects
  • The drug’s effect in humans

As more trials are conducted, the number of participants usually grows. The company will gather preliminary data on patients who have the drug’s target disease to see how well the drug works and determine the optimal dosage. Various types of clinical trials can be used to gather more specific data that will help the drug sponsor’s ultimate goal of approval. For example, the test drug might be studied alongside an already approved drug to compare relative advantages and risks.

3. FDA New Drug Application (NDA) Review

NDA review is the formal step of asking the FDA to approve a new drug for marketing in the United States. Prior to submission, the FDA will meet with the drug sponsor to review the information collected up to that point. Submission of the NDA includes all of the animal and human testing data, including analyses, descriptions of how the drug behaves in the body, and manufacturing process details.

Once submitted, the FDA has 60 days to decide whether it will file the NDA for review. If filed, a review team will evaluate the drug’s safety and effectiveness. The FDA also will review the drug’s labeling to ensure it contains appropriate and accurate information for consumers and healthcare professionals. Prior to approval, the FDA is responsible for inspecting facilities where the drug will be manufactured.

The review period varies widely from one drug to another depending on the impact. Accelerated approval may be granted for serious and life-threatening diseases like HIV or cancer. Accelerated approval alters the process in various ways, such as by reducing the length of time to complete a study.

If all of the criteria are met and the FDA determines that the benefits of a drug outweigh the risks, the agency will approve the drug for marketing in the U.S. In some cases, however, the FDA will issue a complete response letter that explains any problems preventing the drug from being approved.

4. Post-Approval Risk Assessment

Continued post-marketing surveillance of a drug’s adverse effects is another essential function of the FDA. It is impossible to predict every potential outcome during the approval process. Therefore, the FDA maintains a system of post-marketing surveillance and risk assessment programs to identify these unforeseen safety issues after a drug hits the market.

Program Description
Adverse Event Reporting System (AERS) The AERS database provides storage and analysis of safety reports for approved drugs and biological treatments, such as TNF inhibitors.
MedWatch The MedWatch program offers a method for health professionals and others to report serious drug reactions or other pharmaceutical issues.  Through its safety communications, Medwatch helps keep the medical community informed about the latest problems in patient care. MedWatch data also feeds into the AERS database.
Division of Drug Marketing, Advertising and Communications This division within the FDA provides useful information about drug advertising and other marketing efforts. The group keeps manufacturers compliant with current regulations by performing surprise inspections at pharmaceutical company facilities where the drugs are made and distribution.

Continued Evolution

Since drugs were first regulated in the U.S., policies have continued to change as scientific understanding and technical capabilities have improved. It is important to hold the drug industry accountable for public safety, while also allowing innovation to provide new forms of care for individuals.

No system is perfect, and the FDA drug approval process will continue to change and adapt as new drugs are developed. For example, recently a new “Breakthrough Therapies” designation was implemented to expedite approval of drugs for serious or life-threatening diseases that meet certain criteria. As drug development processes change, the FDA will adapt, as it has in the past, to continue its mission to improve public health and safety.

  1. U.S. Food and Drug Administration. History. (Updated July 25, 2014). Accessed Aug. 12, 2014. 

  2. U.S. Food and Drug Administration. Summary of NDA Approvals & Receipts, 1938 to the present. (Updated Jan. 18, 2013). Accessed Aug. 12, 2014. 

  3. U.S. Food and Drug Administration. How Drugs are Developed and Approved. (Feb. 13, 2014). Accessed Aug. 12, 2014. 

  4. U.S. Food and Drug Administration. Drug Approval Process. (n.d.) Accessed Aug. 12, 2014. 

  5. University of Southern California. Preclinical Trial. (n.d.). Regulatory Science. Accessed 12 Aug., 2014.