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Human Trials


What are clinical trials?

Clinical trials are a way to test new methods of diagnosing, treating, or preventing health conditions. The goal is to determine whether something is both safe and effective.

A variety of things are evaluated through clinical trials, including:

Effectiveness of medications, minimum and ultimate dose, medication combinations.

Based on positive results from the preclinical research, we are ready to move forward with a clinical trial to see how well it works in humans. Clinical trials happen in several phases during which different questions are asked. Each phase builds on the results of previous phases.

Phase 0

In this phase of a clinical trial a very small number of people are tested, usually fewer than 15. We will use a very small dose of medication to make sure it isn’t harmful to humans before they start using it in higher doses for later phases.

If the medication acts differently than expected, additional preclinical test at the University will be conducted before deciding whether to continue the trial.

Phase I

During phase I of a clinical trial, we will spend several months looking at the effects of the medication on about 20 to 80 people who have no underlying health conditions.

This phase aims to figure out the highest dose humans can take without serious side effects. Each participant is monitor very closely to see how their bodies react to the medication during this phase.

While preclinical research usually provides some general information about dosing, the effects of a medication on the human body can be unpredictable.

In addition to evaluating safety and ideal dosage, we will also look at the best way to administer the drug, such as orally, intravenously, or topically.

According to the FDA, approximately 70 percent Trusted Source of medications move on to phase II.

Phase II

This phase of a clinical trial involves several hundred participants who are living with the condition that the new medication is meant to treat. They’re usually given the same dose that was found to be safe in the previous phase.

We will monitor participants for several months to see how effective the medication is and to gather more information about any side effects it might cause.

While phase II involves more participants than earlier phases, it’s still not large enough to demonstrate the overall safety of a medication. However, the data collected during this phase helps to come up with methods for conducting phase III.

The FDA estimates that about 33 percent Trusted Source of medications move on to phase III.

Phase III

Phase III of a clinical trial usually involves up to 3,000 participants who have the condition that the new medication is meant to treat. Trials in this phase can last longer than one year.

The purpose of phase III is to evaluate how the new medication works in comparison to existing medications for the same condition. To move forward with the trial, we need to demonstrate that the medication is at least as safe and effective as existing treatment options.

To do this, we use a process called randomization. This involves randomly choosing some participants to receive the new medication and others to receive an existing medication.

Phase III trials are usually double-blind, which means that neither the participant nor the investigator knows which medication the participant is taking. This helps to eliminate bias when interpreting results.

The FDA usually requires a phase III clinical trial before approving a new medication. Due to the larger number of participants and longer duration or phase III, rare and long-term side effects are more likely to show up during this phase.

When we demonstrate that the medication is at least as safe and effective as others already on the market, the FDA will usually approve the medication.

Roughly 25 to 30 percent Trusted Source of medications move on to phase IV.

Phase IV

This phase of clinical trials happen after the FDA has approved medication and involves thousands of participants and can last for more than a year.

This phase is used to get more information about the medication’s long-term safety, effectiveness, and any other benefits.

The bottom line

Clinical trials and their individual phases are a very important part of clinical research. They allow the safety and effectiveness of new drugs or treatments to be properly assessed before being approved for use in the general public.