Phase 1
The investigational drug is administered to a small number of healthy volunteers to:
• determine the optimal dose,
• investigate tolerance,
• investigate possible toxicity.
Phase 2
The investigational drug is administered to about 100 patients in order to:
• test the efficacy,
• list the side effects.
Phase 3
The investigational drug is administered to an even larger number of patients (often thousands) in order to:
• confirm the balance between benefits and risks,
• investigate the effects and compare them against existing drugs or against a placebo.
Phase 4
The investigational drug is marketed and used by an even more heterogeneous group of patients. This allows for close monitoring of side effects.
All phases of a clinical trial are carried out under the supervision of a clinical investigator.
And what happens then?
Once the medicinal product has been marketed, suspected adverse reactions may be reported to the FAMHP. The analysis of side effects allows the FAMHP to assess the safety profile of the medicinal products and take action if necessary.
Drug manufacturers may also organise trials to investigate long-term safety and efficacy.
The efficacy of the drug may also be evaluated in populations other than those initially studied or in other indications.