New to Clinical Trials?

Let’s break down the process to make it easy to understand.

Before a drug is made available to the public, it must go through several phases of clinical research and regulatory approvals that show that it is safe and effective in treating a specific disease within the patient population that participated in the clinical trial. Most available medications are the result of past clinical research.

Without clinical trials and volunteer study participants, there would be no new medications.

What is a clinical trial?

A clinical trial is a type of research study designed to learn if an investigational drug, device, or procedure is safe, how it works in the body, and if it works to treat a specific disease. “Investigational” means that regulatory authorities, such as the FDA (Food and Drug Administration) in the US or the EMA (European Medicines Agency) in Europe, have not yet approved it for use for a particular condition, disease, or patient population.

Who is involved?

Clinical trials for investigational drugs are done in steps or "phases."

Who is involved?

Clinical trials for investigational drugs are done in steps or "phases."

Phases of Clinical Research

Clinical trials for investigational drugs are done in steps or "phases."

Each clinical phase has a different purpose and helps the study researchers answer specific questions about the drug being tested.

These phases are designed to minimize risk to study participants and also advance clinical research.

If an investigational drug fails during any clinical phase, it does not move into the next phase of research.


Pre-clinical trials are conducted in a laboratory and evaluate safety and potential effectiveness. If proven to be effective and safe, the investigational drug may move into clinical trials in humans.


Phase I clinical trials evaluate the potential safety profile and possible or likely side effects of an investigational drug, in most cases in a small group of healthy people.


Phase II clinical trials further identify side effects and risks associated with the investigational drug and help to determine which dose of the drug works best. Phase II clinical trials are usually conducted with a larger group of people than Phase I clinical trials.


Phase III clinical trials further evaluate an investigational drug’s safety, effectiveness, and side effects in an even larger group of people who have been diagnosed with the medical condition for which the drug is being studied. Phase III clinical trials help to confirm the findings of earlier research and may compare the investigational drug to existing approved treatments or to no treatment, possibly using a placebo. A placebo looks like the investigational drug but does not have the active ingredient. If the investigational drug proves to be safe and effective during phase III trials, it is submitted to the FDA/EMA for approval.  


Phase IV clinical trials refers to ongoing testing of a drug that occurs after that drug has been approved and made available to the public, most often to evaluate its long-term effectiveness.

Still have questions?

To learn more about clinical trials and whether participation might be right for you or someone close to you, please speak with your doctor.

Keep connecting.

We know you're interested in signing up for Takeda's WeConnect to get direct communication about Takeda clinical trials, but just in case you are looking for other ways to get involved – please review the information below.

Plasma donation.

Plasma-derived therapies are critical, life-saving medicines that many people with rare and complex diseases rely on. Global demand for plasma-derived products, mainly immunoglobulins, has increased dramatically in recent years.

Plasma Donation and BioLife Plasma Services
BioLife Plasma Services is Takeda’s global plasma collection network and an industry leader in the collection of high-quality plasma that is processed into life-saving plasma-based therapies that benefit thousands of people every day.

Learn more about plasma donation and how to help people who require life-saving plasma-based therapies by donating your plasma.

Physician looking to connect?

We at U.S. Medical Affairs at Takeda share your passion for science, evidence-based medicine, and commitment to promoting better health and brighter futures for our patients through potentially innovative medicines.

Our goal is to be readily available to support clinicians and researchers in whatever way we can. We believe the best way to improve disease outcomes is through robust and open communication about the science and clinical evidence.

That’s why we love to hear from medical professionals—to hear your questions, to understand what you’re seeing in the clinic, and to discuss research.

You are encouraged to report side effects or quality issues to Takeda at If you prefer, you can report to the Health Authority.

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