Clinical trial is a “research study conducted to find answers to health related questions in which subjects/patients receive one or more diagnostic, therapeutic, or other types of interventions/treatment (or no intervention)” so that researchers can determine the effects of the interventions on biomedical or health related outcomes including new treatments (such as drugs, novel vaccines, dietary supplements, dietary choices, and medical devices).
Phases of Clinical Trials:
Clinical trials are generally conducted in four phases and a Early Phase 1 (formerly known as Phase 0) trials are optional first-in-human trials.
Early Phase 1: It used to describe exploratory trials conducted before traditional phase 1 trials to investigate how or whether a drug affects the body. These trials involve very limited human exposure to the intervention and have no diagnostic or therapeutic goals (for example: screening studies, micro-dose studies).
Phase 1(Screening for safety/Human Pharmacology): phase 1 will focus on the safety of a intervention/drug and are usually conducted with healthy human volunteers, and the principal goal is to determine the safety of a drug like serious adverse events (SAE's). These trials usually experimental treatment is given to a small group of subjects for the first time to evaluate its safety, side effects and dosage range.
Phase 2 (proof of concept/Therapeutic Exploratory/Establishing the preliminary efficacy of the drug, usually against a placebo): In this phase describe clinical trials that gather preliminary data on whether a intervention/drug works in subjects who have a certain condition/disease (the drug’s effectiveness) and the experimental treatment is given to a larger group of subjects (100 to 300) to evaluate its safety and efficacy.
Phase 3 (Therapeutic Confirmatory/Final confirmation of safety and efficacy): Phase 3 studies gather more information about a drug’s safety and efficacy by studying different populations and different dosages and by using the different drug in combination with other drugs and experimental treatment is given to large groups of subjects (1,000 to 3,000) to confirm its efficacy, monitor side effects, compare to current treatment options. If the experimental treatment works well in this Phase 3, investigator/researchers can submit an application(New Drug Application(NDA)) to the U.S. Food and Drug Administration (FDA) asking permission for marketing. The FDA approval process generally takes about a year. Research continues in some cases even after the FDA has approved a treatment.
Phase 4 (Safety during sales): The phase 4 trial is also referred to as post-marketing surveillance(PMS) and it is conducted after the drug is approved for marketing and available to the general public(real world). The main objective of the phase 4 trial is to determine the performance of the drug in real life scenarios to study the long-term risks and benefits of the drug and to discover any SAEs and rare side effects which only be found in large groups of people. These trials gather additional information about a drug’s efficacy, safety or optimal use.
Happy Learning !!! :)
