Understanding the 4 Phases of Clinical Research

Modern medicine improves people’s lives every day. Medicine, medical treatments and devices are developed through clinical research. Clinical research is a scientific way to study treatments or procedures and how they may help people.

New treatments or interventions must go through several stages to determine their safety, effectiveness and side effects. These stages, or phases, have certain requirements for each one.

What Are the 4 Phases of Clinical Research?

The early phase in a clinical trial is known as phase 0. It is an exploratory phase to understand how a drug or treatment behaves in the body to improve the chance for success. Phase 0 is the first time a drug or treatment will be given to human beings.

About 10-15 healthy people participate in these early phase trials, which help researchers show proof of concept. Next, we will describe the characteristics of the main four phases of clinical research trials.

Phase 1: Safety

Phase 1 is a clinical trial phase focused on the safety of a new drug. The goal is to determine the drug’s most beneficial dosage. Phase 1 studies try to find out how much of a drug can be given with the least severe side effects.

• It includes 20-100 people.
• May last several months.
• No inactive treatments or placebos are used in phase 1.

Phase 2: Effectiveness

Once the treatment or drug is considered safe enough, it enters phase 2 of the clinical research study. The participants have the condition or disease being studied. They are watched closely for short-term side effects.

The treatment is analyzed for its effectiveness or its ability to produce the desired result.

• 100-300 participants are given the drug.
• May last several months up to two years.
• No placebos are used in phase 2.

Phase 3: Compare and Confirm

Phase 3 clinical trial participants have the condition or disease being studied. This phase aims to confirm drug safety and effectiveness. Participants are often assigned at random to receive the new treatment or an alternative option, like a placebo or the standard treatment for a particular condition or disease.

• Includes 300 to 3,000 people.
• It lasts one to three years.

Phase 3 is the point at which a study may end if the side effects are not manageable. The U.S. Food and Drug Administration reviews information collected in phase 3 when it considers new treatments for approval.

Phase 4: Approved, Available and Continued Observation

Once the FDA approves the drug, it can be sold to the public. Phase 4 of a clinical research study involves continued observation of thousands of people using the treatment. People are watched for long-term side effects, benefits, and safety of the drug.

How Are People Found Eligible for Studies?

A clinical research trial protocol, or planned procedures, determines the requirements for each study. The protocol dictates which people are eligible for a specific research study. Factors for eligibility in studies may include:

• Healthy volunteers
• Patients having the condition or disease being studied
• Demographics such as age, gender and/or race

Other requirements might be based on a person’s ability to commit to the study long-term, their pain tolerance or other health conditions affecting study results.

In summary, clinical research aims to provide better treatments than those currently available. Clinical trials can lead to life-changing interventions for people managing disease daily. Scientific studies bring innovation and hope to doctors and patients alike.