What are the Phases of Clinical Research?
Studies involve testing the investigational drug in a small number of healthy adult volunteers. The sole objective of these studies is safety. These studies are designed to determine how the drug is metabolized by the body and what pharmacologic actions the drug has. One objective of these studies is to determine the best way to administer the drugs (i.e., the preferred route).
Studies help determine how safe and effective a drug is, common short-term side effects of the drug, pharmacokinetic effects of the drug (i.e., the amount of drug that gets into the bloodstream, how quickly it gets there, and how long it stays there) and pharmacodynamic effects of the drug (i.e., the effects of the drug on the body). These studies involve a larger group of patients (e.g., 100 to 200 patients) and are usually conducted in patients who have the medical condition for which the drug is being studied. These studies are used to identify the dose range of the drug that will be tested in subsequent larger studies (i.e., Phase III studies).
Studies provide additional information about safety and efficacy when the drug is used in the way it is intended to be marketed. These studies are initiated only after earlier studies have demonstrated that there is an acceptable risk to benefit profile (i.e., the risk of taking the drug is outweighed by the potential benefit of the drug to the patient). These large studies are usually conducted at many different study centers; up to 10 to 30 study centers and between 500 and 5,000 patients may be included. These studies are used to confirm the indication and best dosage for the drug.
Studies are conducted after the drug is available for sale (i.e., post-marketing studies) and they evaluate how safe and effective the drug is when exposed to the “real” population. These studies evaluate parameters such as different formulations, dosages, treatment durations, and drug interactions. The Food and Drug Administration (FDA) may require a company to conduct certain Phase IV studies as a provision for product approval. These studies may include new age groups, various races and other types of patients. These studies are useful for detecting and defining previously unknown or inadequately quantified adverse events and related risk factors. The size of these studies is broad and can range from less than 100 to over 20,000 patients.
¿WHO SPONSORS CLINICAL TRIALS AND WHERE DO THEY TAKE PLACE?
Clinical trials are sponsored by government agencies such as the National Institutes of Health (NIH); pharmaceutical companies; individual physicians or investigators; health care institutions such as health maintenance organizations (HMOs); and organizations that develop medical devices or equipment. Clinical trials can take place in a variety of locations, such as hospitals, surgical centers, universities, or doctors’/dentists’ offices.
- Medical institutions
- Voluntary Groups
- Phamaceutical companies
- Federal Agencies (cooperative group research)
– NCI (ACRIN is funded through the NCI as a cooperative group)
WHAT IS A PLACEBO?
A placebo is an inactive substance (pill, liquid, or powder) that has no treatment value. It may be referred to as a “blank” or “sugar pill.” In placebo-controlled clinical trials, experimental treatments are compared with placebos to assess the treatment’s effectiveness.
Some participants in these studies may receive placebo rather than active treatment. In pain studies, patients who receive placebo (as well as those who receive active treatment) will always have access to ‘rescue medication’, which is a standard pain medication given for the condition or procedure being studied. As soon as you feel that you need more pain medication, you will be given a rescue dose of the standard pain medication. Asking for rescue pain medication will not in any way have a negative impact on your participation in the study.
WHAT IS AN ADVERSE EVENT?
The term adverse event, as used in the context of clinical research, means any untoward medical occurrence in a patient administered a pharmaceutical product which does not necessarily have to have causal relationship with this treatment. Adverse events can be a symptom (e.g., a headache), a finding during a physical exam (e.g., elevated blood pressure), a syndrome or disease (e.g., “flu syndrome” or meningitis), or an abnormal laboratory value.