The road toward Food and Drug Administration (FDA) approval begins long before the agency actually gets involved.

The pharmaceutical company starts with its own laboratory research and animal trials. Later, it takes the first formal step in the FDA’s pharmaceutical approval process by submitting an investigational new drug (IND) application.

The medical device approval process follows a similar path.

The First Step: An Investigational New Drug Application

The IND application is submitted to the FDA on the strength of the data already assembled by the pharmaceutical company or medical device manufacturer, including the results of animal trials. A successful IND application clears the way for human trials, also known as “clinical trials.”

The Clinical Trial Process

The clinical trial process consists of three phases. Each phase must be completed successfully in order to move on to the next.

Phase I Clinical Trials

Phase I clinical trials are designed to measure the impact of the drug on a healthy person. At this stage, there is no investigation into the efficacy of the drug for its intended purpose. Instead, the drug is tested on a small number of healthy subjects to determine the most common side effects, their severity, and how the drug is processed out of the body.

If the Phase I trials do not reveal unacceptable risks or toxicity, the clinical trial process moves forward.

Phase II Clinical Trials

Phase II trials are slightly larger than Phase I trials, ranging from dozens of volunteers to a few hundred. This phase focuses on the effectiveness of the drug for people with a particular disease or medical condition. In Phase II trials, some patients receive the drug under investigation and others receive a placebo. Then, the outcomes for the two groups are compared. Although the purpose of this phase is to measure efficacy, clinicians continue to document and evaluate side effects.

When this phase is successfully completed and effectiveness has been demonstrated, the FDA and the drug company negotiate the specifics of the large-scale clinical trial for Phase III.

Phase III Clinical Trials

Phase III trials are intended to gather more extensive data about both the safety and effectiveness of the drug. These trials typically cover a longer time period, involve several hundred to a few thousand subjects, and test variables such as patient demographics, dosage, and combination with other drugs.

Note that each phase of clinical trials is conducted or commissioned by the drug company or medical device manufacturer, not an official from the FDA.

The Final Step: A New Drug Application

After clinical trials have been completed, the company submits a New Drug Application (NDA) formally requesting approval to market the drug in the United States. This submission includes data and analysis from the original animal testing and the human trials, as well as scientific information about how the drug is manufactured and processed.

The FDA has 60 days to determine whether the application is complete and ready for review. The goal is usually to have the review complete and action taken within 10 months from filing acceptance. In a few cases, the process may take longer, and in others it may be expedited. For example, a more streamlined process is available for generic drugs that are substantially equivalent to a drug that has already received approval. In addition, a priority drug may be fast-tracked for action within six months.