Clinical trials are a crucial step in the process that transitions new medications, medical devices, and treatments from conception to being accessible on the market. Numerous trials are conducted daily around the globe. Researchers move from laboratory tests to studies involving animals and cells. These initial studies are referred to as pre-clinical studies, which assist the research or pharmaceutical company in deciding whether to move forward with additional trials. If the pre-clinical results show promise for a new treatment or cure, clinical trials are initiated to assess the treatment on human subjects. The phases of clinical trials include:
Phase 0
This phase marks the initiation of a human clinical trial. In the first tests involving human participants, the treatment or drug is administered in micro-doses. A small quantity of the treatment or drug is given to a group of around 12 participants. The individuals are closely monitored to determine if the effects align with expectations. The dosage is typically too low to be therapeutic, as testing during this phase is designed solely to establish tolerability. This allows researchers to evaluate the feasibility of numerous drugs and formulate plans based on human data rather than animal data.
Phase I
The first phase in which the standard therapeutic dose is administered to humans. There are various types of phase I study, including the single ascending dose study, the multiple ascending dose study, and the food effect study. Food effect studies are conducted to investigate any potential variations in the effectiveness and absorption of the drug when taken with or without food.
Different dosages are tested to identify the most effective one. These trials are generally conducted at clinics to enable close monitoring of participants for side effects.
Phase II
These trials commence after the drug’s safety has been verified in phases 0 and I. Phase II involves larger groups of more than three hundred participants. The objective of these clinical trials is to examine the efficacy of the treatment and drug. Researchers begin to monitor side effects, safety, and tolerability in this broader group.
Phase IIA
A more potent dosage is assessed.
Phase IIB
Studies are conducted to evaluate how effective the medication is at this established dose.
Phase III
Phase III trials typically involve the largest participant group of any trial phase, often comprising thousands of individuals. They are designed to provide data on the confirmed effectiveness within a broader population, further examine any side effects, and allow the drug to be evaluated against existing treatments.
To prove the drug’s effectiveness and safety before the FDA grants approval, two successful phase III trials are required. The results of these trials are compiled into a comprehensive document outlining the methods and findings, which is then submitted to regulatory agencies in other countries for their consideration in approving the drug for sale.
Phase IV
Phase IV trials occur after a new treatment or medication has been launched on the market. These studies aim to identify any long-term adverse side effects that may not have been apparent initially or to assess the drug in specific population groups that were not part of the earlier trials.