Phases of clinical Trials
There are three phases of trials. They are phase 1, phase 2 and phase 3 trials. Each is performed at various levels and has various goals.
Aims of phase 1 trial:
Phase 1 trials are conducted to find out,
1. Safe dosage range of the drug tested. This is done by the SAD and MAD tests on the subjects chosen
2. Side effects. Again, with the SAD and MAD tests, the side effects or the adverse effects of the drug can be identified.
3. How the body cope with the new drug. This is very essential. Since, a drug may cure a disease, but it may leave the body vulnerable to other attacks or the body may be affected by the drug itself.
4. If the treatment has shrunk the occurrence of the disease. The treatment in this phase itself could be enough for shrinking the effects of the disease. Such possibilities are analyzed.
5. The ‘dose escalation study’ is performed with the dose of the drug.
Aims of Phase 2 trials:
The phase II trials aim in finding out,
1. If the treatment of the phase 2 works good enough to pass to the phase 3 trials.
2. Which stages or type of disease considered, the treatment works well for.
3. Example: cancer. Various types of cancer patients may be involved. The drug may perform well for leukemia rather than lung cancer. Under circumstances, the effectiveness of the treatment is evaluated specific to the type of the cancer.
4. Greater information on the dose and side effects of the drug used and how to manage them.
Aims of Phase 3 trials:
Phase 3 trials are aimed to find out,
1. How effective is the current treatment in comparison with the already existing best standard of treatment
2. Idea to get a broader view on how the treatment works as a whole
3. All the phase trial results are sometimes combined to form the Meta analyses.
4. The side effects of the drug once released onto the market
