The approval of a new therapy is no small miracle. After a potential therapy has been thoroughly tested in a lab setting and deemed promising, it must pass through a strictly regulated approval process that tests its efficacy and safety on people. This process spans three phases of clinical trials, or research studies, each with a different purpose and involving an increasing number of people.

Clinical trials follow strict, scientific standards that protect patients and help produce reliable trial results. Every clinical trial has a protocol, or study plan, that describes what will be done during the trial, how the trial will be conducted and why each part of the trial is necessary.

Before a clinical trial on a potential therapy can start, Biogen submits an Investigational New Drug (IND) in the United States, or a Clinical Trial Application (CTA) as it’s called outside the U.S. , to the local regulatory agency. We work with regulatory agencies around the world, including the Food and Drug Administration (FDA) in the U.S. and the European Medicines Agency (EMA) in Europe. The application describes the results of preclinical testing and clearly outlines the plan for conducting clinical trials.

Trials in Phase One emphasize safety and are usually conducted with healthy volunteers. The goal is to learn how the potential therapy is metabolized and to uncover its most frequent and serious side effects.

Trials in Phase Two gather preliminary data on how the potential therapy works for people with the target disease or condition. Some trials compare results for two different test groups: participants receiving the potential therapy and participants receiving a different treatment – either another drug or a placebo. Researchers continue to pay close attention to safety and possible side effects.

In this final clinical phase, investigators gather more comprehensive information about a potential therapy’s safety and effectiveness. Trials might examine different patient populations, compare different dosage amounts of the potential therapy or combine it with other treatments.

Once Phase Three is completed, the potential therapy can be filed with regulatory authorities like the FDA or EMA,which can then approve as a therapy for public use.

After a therapy has been approved, regulatory agencies often require additional studies. These post-marketing studies may evaluate the therapy on new patient populations, monitor the its long-term impact or compare the therapy with other therapies.