Edited by Michelle Asselin
Have you ever wondered how drugs go from the research lab to the shelf at your local pharmacy? This can require years of research with a lot of steps, all to make sure what you find at the pharmacy is both safe and effective. With that in mind, let’s go on the journey of a new drug!
Step 1: Discovery and Development
Research for new drugs begins in the lab, where researchers consider thousands of compounds to develop into medical treatment. There are several factors to consider when discovering new drugs:
New information in the targeted disease or condition that could influence how the drug can treat or slow its progression
Current drugs and treatments for the targeted disease or condition
New technologies that allow the drug to target specific sites within the body
Tests available to study the drug and understand its benefits and harms
Despite the many compounds considered, only a small portion of them will be studied further. Researchers conduct experiments on potential drug candidates to see how the compound will be taken or administered; how the compound is absorbed, metabolized, and excreted in the body; and how the compound affects the body. Additionally, it is important to compare the compound to similar drugs that treat the same disease and understand how the compound interacts with other drugs and treatments.
Step 2: Preclinical Research
After researchers decide on a compound with potential benefits, they must find out its potential harm, also known as drug toxicity. If too much of a drug is in the body at a given time, it can lead to unwanted effects. These studies, typically done using animal models, are not very large, but they are important to decide how much of the potential drug can be given without causing harm. Researchers move onto the next step if the benefits outweigh the risks.
Step 3: Clinical Research
If the new drug is deemed to be safe, it will be further studied in people in clinical trials. There are typically four main phases from early, small-scale trials to late-stage, large scale studies (see the table below). The main goal is to find the therapeutic margin, which is the dose of drug that is beneficial to the patient without causing harm. In each phase, researchers develop research questions and objectives and must decide who will be part of the study, how long the study will last, how much of the drug is given to patients, what data will be collected, and how data will be analyzed.
Step 4: Drug Review
After Phase III studies, data from all clinical trials are compiled and sent to governing bodies to analyze drug safety and if the new drug works for its intended use. In Canada, this information is sent to Health Canada, while in the United States, it is sent to the Food and Drug Administration (FDA). In addition to findings in clinical trials, researchers must also include a proposed drug label for the new drug, safety updates, patent information, and directions for how to use the drug. Review may take months, but if the drug is approved, the company can begin to sell the new drug.
Step 5: Post-Market Safety Monitoring
Even if a new drug is approved, it is still monitored for side effects while it is being sold. Because clinical trials are relatively small, sometimes side effects do not appear until it is introduced to the public. It may take months, even years, to understand drug safety. Governing bodies continue to monitor potential issues with the drug, to use this information to update cautions in the drug label, and to decide if further measures should be taken for more serious issues. In these ongoing Phase IV studies, drugs can (and have been) pulled from the market based on findings from these studies.
Speeding Up the Approval Process
There are four ways the approval process can be sped up to get a new drug to market faster:
Fast Track: The drug is used to treat a serious condition and fill an unmet medical need.
Breakthrough Therapy: The drug demonstrates a substantial improvement as compared to current treatments.
Accelerated Approval: The drug fills and unmet medical need and is required to be approved based on measurements that predict clinical benefits.
Priority Review: The drug will be reviewed by the governing body within 6 months of receiving information gathered in clinical trials.
The FDA reviewed COVID vaccine applications under Priority Review, meaning they moved faster than the typical 10 months of standard review. However, no steps were skipped, and no safety or efficacy data was compromised! Instead, clinical trial phases were overlapped to speed up the process, as illustrated in the picture below.
In conclusion, it can take 10-15 years and billions of dollars of investment for a new drug to appear at your local pharmacy. With new technologies like gene targeting and the automation of many clinical research tasks, researchers and drug developers can work quickly and tirelessly to find the next new drug that will help save lives.
The Drug Development Process. United States Food and Drug Administration. Updated January 4, 2018. Accessed March 12, 2022. https://www.fda.gov/patients/learn-about-drug-and-device-approvals/drug-development-process
Buckley LA, Bebenek I, Cornwell PD, et al. Drug Development 101: A Primer. Int J Toxicol. 2020;39(5):379-396. doi:10.1177/1091581820939083
Fast Track, Breakthrough Therapy, Accelerated Approval, Priority Review. United States Food and Drug Administration. Updated February 23, 2018. Accessed August 9, 2022. https://www.fda.gov/patients/learn-about-drug-and-device-approvals/fast-track-breakthrough-therapy-accelerated-approval-priority-review
Eder J, Herrling PL. Trends in Modern Drug Discovery. Handb Exp Pharmacol. 2016;232:3-22. doi:10.1007/164_2015_20