What is a Phase 2 Clinical Trial?

Phase II of a clinical trial involves hundreds of participants who are living with the condition that the new drug is meant to treat. Phase 2 clinical trials are usually administering the same dose found safe in the previous phase.

Research investigators monitor participants for several months or years to see how effective the drug is and to collect more information about any adverse effects it might cause.

While phase II involves more participants than the earlier phases of clinical trials, it is still not large enough to demonstrate the overall safety of a treatment. However, the data collected during this phase helps investigators develop methods for conducting phase III.

The FDA estimates that about 33% of medications move to phase III.

Understanding Clinical Trial Phases

Clinical trials follow a specific timeline, from early, small-scale, phase 1 clinical studies to late-stage, large-scale, phase 3 studies. While there are many clinical trial phases involved in developing a new treatment, the phases that make up clinical research are all parts of drug development that involve human participants.

Purpose of Phase 2 Clinical Trials: Efficacy and Side Effects

The Phase 2 clinical trial aims to determine the correct dosage and effectiveness in treating a particular disease. Testing normally takes place with a larger number of participants who have the disease. There are many different ways a trial sponsor can conduct their trial, but the plan typically involves assigning participants to different treatment groups, where each group receives different doses or delivery of the treatment.

Normally, there is a "control group" that receives either the current standard treatment, if another type of treatment is already available for that disease, or a placebo treatment, such as a "sugar pill" or harmless injection that doesn't contain the treatment.

The health of the group of patients who received the different types of treatment is then compared to the control groups. However, if the results show that the treatment did not work better than the current standard of care or even caused an acceleration of the disease or other unexpected serious side effects, the FDA may not permit the trial to proceed to Phase 3. Normally, testing that treatment is discontinued; it "drops out" of the running for making it to the market.

Key Points of Phase 2 Clinical Trials

• A larger group of patients with the same illness receive the new treatment in a phase II study. They’re treated using the dose and method found to be the safest and most effective in phase I clinical studies.
• Usually, in phase II trials, everyone gets the same dosage. But some phase II studies randomly assign participants to different treatment groups. These groups may get different dosages or get the treatment in different ways to determine which provides the best balance of safety and response.
• Phase II studies may be conducted at major health centers, community hospitals, or even doctors’ offices.

Larger groups of patients get the treatment in phase II trials, so less common side effects may be seen. If enough patients benefit from the treatment, and the side effects aren’t too bad, phase III clinical trials are begun.

Number of Participants

A Phase II clinical trial uses more people (100 to 300). While the emphasis in Phase I trials is on safety, Phase II emphasizes effectiveness. This clinical trial phase aims to obtain preliminary data on whether the drug is effective in people with a certain disease or condition. These trials also continue to study safety, including short-term side effects. This phase can last up to several years.

Uses of Treatment Groups

A Phase II clinical trial can last up to several years. Volunteers sometimes receive different treatments. For example, a phase II clinical trial could have 2 treatment groups.

Group 1: People who receive the usual treatment for the condition. This is also called the standard treatment. It is the best treatment known.

Group 2: People who receive the usual treatment plus the new treatment doctors are studying.

Or a phase II clinical trial can have 3 groups. Volunteers in each group get a different dosage of the treatment physicians are studying.

If the phase II trial shows the treatment works and is as safe as the standard treatment, physicians can proceed to a phase III trial.

Uses of Placebo

Sometimes phase 2 trials compare a new treatment to a placebo. A placebo is a ‘dummy’ drug that looks the same as the new treatment but does nothing.

A placebo may be used in clinical trials if there is no standard treatment to compare the new treatment with or if the new treatment being tested is being added to a standard treatment.

Efficacy and Side Effects Evaluation

In Phase 2 clinical studies, researchers administer the drug to a larger group of patients with the disease or condition for which the drug is being developed. Larger groups of patients with the target condition undergo proof-of-concept and dose-finding trials, then randomized trials to further delineate clinical efficacy, outcomes, and adverse events.

Phase 2 studies provide researchers with more safety data. The research team uses these data to refine research questions, develop research methods, and design new Phase 3 clinical research protocols.

Length of Study

Phase 2 trials, which examine the efficacy and side effects of a drug or treatment, typically last several months to two years.

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At Santos Research Center, Corp., we have completed over 400 clinical trials. We make use of efficient and reliable systems to plan and manage quality medical research studies.

For more information about Phase II clinical trials, you may visit us at www.santosresearch.com.

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