There are different phases of a clinical trial. In the early phase, a drug’s safety is tested whereas in the later phases, the effectiveness of a new treatment or a drug is compared to existing treatments. Mainly, there are three phases in a trial but some trials also have a phase 0 and phase 4 that is done once the drug is licensed.
Early phase in a clinical trial is the first step towards testing new medicines developed in a laboratory. The main purpose of this phase is to find out the correct dosage of a new medicine, how human body absorbs the drug, what are its side effects and toxicities and how often the drug can be given to ensure that its effect remains. The timely and strategic collection of data in the early phase clinical trial is necessary for the development process. It is also necessary for critical decision-making.
The early phase involves a small number of people. They are given only a small dose of the drug. The researchers mainly look for the following:
- Has the effect of the drug reached the ailment
- How the drug has been behaving with the human body
- How the body is responding to the drug
In the first phase, a new treatment is tested on humans. It is done for establishing how a certain treatment is acting on humans and what are its safety limits? The treatment is tested on a small group of patients in increasing dosages. The researchers watch the patients carefully to see if there are any harmful side effects happening.
Phase 2 clinical study is done for testing the safety of the drug and in phase 3, the new treatment is compared to the existing treatment to assess the effectiveness.
