What Are the Necessary Phases of a Clinical Trial?
Clinical studies are a vital component in the development of newer, better treatments for all kinds of medical conditions. They’re also one of the least understood by those who don’t have firsthand knowledge of what clinical trials fully entail.
Below, we’ll explore every phase from start to finish in hopes of clarifying how exactly clinical studies work.
It might seem odd to label the first step in any process with the number zero, but it makes sense here. Phase 0 of a clinical trial is actually something of a pre-trial or a mini-trial all on its own.
In Phase 0, researchers distribute extremely small doses of the treatment they’ll be testing to a similarly small group of people, usually numbering around 10 to 15. This is to make sure that the drug in question is not harmful to human subjects before a larger study can be done. Only after Phase 0 is finished can a true clinical study take place.
Now that the clinical trial has begun in earnest, Phase I sees researchers distributing small doses of their treatment to patients and observing the side effects. In each subsequent visit, the dosage is steadily increased.
This enables researchers to manage any negative side effects in a way that is safe for the trial participants, while also recording just how much of their drug is ideal for future usage. By increasing the dosage over time, researchers can gauge when the severity of the side effects of a drug outweighs its potential benefits.
Once an optimal dose is decided upon, Phase II of the clinical study can begin. In this phase, the goal is to determine how well the drug works as a treatment for a given condition.
Utilizing a larger pool of participants and lasting anywhere from several months to several years, Phase II is a slow, meticulous process that involves running numerous tests on patients in order to determine a reliable standard of efficacy. It also allows researchers to see what long-term side effects may arise from more extensive usage.
Taking the data gathered through previous phases, Phase III in a clinical trial involves comparing the drug being studied to any other drug or drugs currently considered a go-to treatment for a given condition. In other words, where Phase II is about finding out how well the drug works in general, Phase III more specifically about if it works better than the extant alternatives.
There are multiple ways a drug may or may not be superior to other options. Is it more effective against a certain affliction? Does it have less severe side effects? Is the dosage smaller? Is manufacturing it less expensive? Etc.
Very few drugs proceed all the way to Phase IV. At this point, the treatment is submitted to the Food and Drug Administration for approval. There, the data collected by researchers is rigorously reviewed prior to said approval. If approval is indeed obtained, that doesn’t mean that all questions about the new drug have been answered, only the most obvious and important ones.
Phase IV involves monitoring the drug as it is used by hundreds of thousands of people over the course of many years. In that time, long-term benefits or complications may be discovered and rare side effects can rear their heads. In that sense, no clinical trial is ever truly finished.