What are the Phases of Clinical Trials?
A new drug typically passes through 3 phases of clinical trials before receiving approval, according to the National Cancer Institute: “Most clinical research that involves the testing of a new drug progresses in an orderly series of steps, called phases. This allows researchers to ask and answer questions in a way that results in reliable information about the drug and protects the patients. Clinical trials are usually classified into one of three phases: • Phase I trials: These first studies in people evaluate how a new drug should be given (by mouth, injected into the blood, or injected into the muscle), how often, and what dose is safe. A Phase I trial usually enrolls only a small number of patients, sometimes as few as a dozen. • Phase II trials: A phase II trial continues to test the safety of the drug, and begins to evaluate how well the new drug works. Phase II studies usually focus on a particular type of cancer. • Phase III trials: These studies test a new drug, a new combina
Clinical trials are usually conducted in distinct phases. Each one is designed to answer specific questions. Knowing the phase of the clinical trial you are considering is important because it may give you some idea about how much is known about the treatment being studied. There are advantages and disadvantages to taking part in each phase of clinical trial. Phase I Clinical Trials ‘ Is the Treatment Safe? These studies are the first ones to involve people as participants. Although the treatment has been tested in lab and animal studies, the side effects in people can’t always be predicted. For this reason, these studies usually include small numbers of people (15 to 50) and are generally reserved for those who do not have good treatment options left to them. Often, people with different types of cancer are eligible for the same study. These studies are usually done in major cancer centers. The main reasons for doing phase I studies are to determine the highest dose of the new treatme
In clinical trials the effects of drugs under investigation are typically compared to that of placebos, which have no pharmaceutical impact, or with comparable drugs already on the market. Clinical trials are allocated to four main clinical development phases. Phase I trials study the safety and tolerability of drugs in healthy volunteers. These trials also provide information on the degree and time course of absorption, distribution in the body, metabolic breakdown and excretion of the compound under investigation. These effects are studied at various dosage levels. This phase also seeks to identify whether the new drug interacts with food or other drugs and could reduce or increase the effects of medications taken simultaneously. Phase I trials include normally 20 to 50 volunteers and treatment duration generally ranges from single dose to multiple doses and from a few minutes up to two weeks. Phase II trials involve patients with the specific illnesses which are targeted by the drug
After being studied in a laboratory and animal studies, most new treatments are examined in a series of clinical trials which follow a progression of steps or phases toward approval by the FDA (Food and Drug Administration). Trials conducted at each phase have a different purpose and are designed to answer different questions. Phase I Trials involve the testing of a new drug or treatment in a fairly small group of people (20-80) in order to evaluate its safety, to determine a safe dose range, and to identify side effects. This type of trial may involve patients who do not have the illness or may involve healthy volunteers. Phase II Trials involve testing the new drug or treatment in people with an illness or condition and usually involves a somewhat larger group of people than a phase I trial. This type of trial seeks to provide preliminary information about the safety and benefits of the new drug or treatment. Phase III Trials are designed to confirm the safety and effectiveness of th
