What is Clinical Research?

Clinical research is research with the goal of improving the diagnosis, and treatment (including rehabilitation and palliation), of disease and injury; improving the health and quality of life of individuals as they pass through normal life stages. Clinical research usually encompasses research on, or for, the treatment of patients (Source: Canadian Institutes of Health Research).

A clinical trial may focus on improving an existing treatment or compare it to another method of treatment. It is an essential platform for the development of new diagnostic, therapeutic and preventive strategies. All drugs used, whether for common or more specialized treatments, were discovered through research.

What are the phases of clinical research?

Basic research, whose main objective is to further scientific knowledge without any distinct benefits, always precedes clinical research.

If a molecule appears to be promising for human application, it must then be tested in a clinical setting where its effectiveness and toxicity will be verified. Clinical studies follow a strict methodology regulated by law and can only take place under specific conditions.

Clinical Trial Phases:

  • Phase 1 The objective of a Phase I study is to verify experimental hypotheses, find the optimal dosage, study how the body metabolizes the drug (changes in the body over time, tolerance and toxicity), determine the best prescription mode and identify side effects. A very small number of healthy subjects (between 15 and 30), or patients for whom all other treatments have been ineffective, are placed under constant medical observation. In oncology, Phase 1 studies are performed with patients who have little or no treatment alternatives, for example when the disease is locally advanced or metastatic or when the tumor is resistant.


  • Phase 2 trial allows the evaluation of the therapeutic action and toxicity of different doses of the product on a small number of people (usually less than one hundred). The aim is to identify the minimal dosage required to obtain a therapeutic effect as well as the maximal non-toxic dosage for humans. This phase usually takes place in a hospital setting to ensure close medical supervision of the participants. 
  • Phase 3 trial aims to demonstrate the therapeutic value of the drug tested and its lack of harmfulness. Phase III trials are conducted in many clinical sites and with a high number of participants that are representative of the patient population for which the experimental treatment is intended (up to many thousands of people). The experimental drug is compared to the best standard treatment, or to a placebo if no standard treatment exists. This phase is the final step before the drug is available to patients.

A fourth phase is sometimes conducted after the medication or treatment has been made available on the market.

  • Phase 4 allows to collect long-term data on the medication once it has been commercialized in order to detect secondary effects, complications or negative consequences due to medication interaction which has not been detected up to this point. The goal is to gain more knowledge of the medication or treatment in real conditions of use by tens of thousands of people. This phase is also called pharmacovigilance.