A type of clinical trial that studies the side effects caused over time by a new treatment after it has been approved and is on the market. These trials look for side effects that were not seen in previous trials and may also study how well a new treatment works over a long period of time. What are test phases? Trial phases at a glance Phase 0 trials Phase 1 trials Phase 2 trials Phase 3 trials Phase 4 trials Trials covering more than one phase Some trials have an earlier stage called phase 0, and there are some phase 4 trials conducted after a drug has been authorized. For example, clinical trial patients may be instructed to follow a strict diet and drug regimen, while phase 4 trials are conducted in regular populations where a variety of different foods and other drugs may be ingested.
Doctors use clinical trials to find out if a new drug, treatment or combination works and if it is safe for people. For more information, see next week about the benefits and potential disadvantages of participating in a clinical research study. Using a computer to group volunteers together prevents research staff from changing clinical trial results. The purpose of a phase 2 clinical trial is to determine the correct dose and effectiveness in treating that particular disease.
There are three phases to complete in the clinical trial process before a sponsor can submit their treatments* to the FDA for consideration for sale in the marketplace. If a new treatment is determined to be safe in phase I clinical trials, a phase II clinical trial is done to see if it works in certain types of cancer. This is called “drug reuse” and sometimes this can shorten the clinical trial or allow acceleration to phase 2 clinical trials, because the phase 1 safety profile was already tested in the previous clinical trial. After completing phase 3 clinical trials, the health of patients who received the different types of treatment is compared to the control groups.
Voluntary participation in clinical trial research helps scientists get new drugs to patients more quickly, but should be carefully considered in conjunction with advice from a healthcare professional. Answering these questions, while giving as few people as possible an unknown treatment, often requires several clinical trials in different “phases”. Each stage of a clinical trial has its own purpose of ensuring that a treatment is safe and effective for public use. At the end of Phase 1, results are collected, analyzed and submitted to the FDA for permission to proceed to Phase 2 Clinical Trials.
A phase III clinical trial tests a treatment that worked well for volunteers in a phase II clinical trial. Clinical trials are conducted only after preclinical findings indicate that the new drug or treatment is likely to be safe and work in people.
