Drug Approval Process
The Canadian Health Products and Food Branch (HPFB) and the Food and Drug Administration (FDA) ensure all drugs and related treatments in Canada and the United States are safe and effective. The HPFB and FDA will not consider or approve the use of a new substance until after completion of studies with scientifically controlled and analysed data. New drug therapies must pass through different stages in order to be approved for use in Canada and the United States. The European Regulatory Authorities (EMEA) follow similar guidelines.
The FDA Approval Process
1. Pre-clinical studies: Crucial laboratory and animal tests that are the key to underpinnings of all medical research and advances in clinical care.
2. Phase I trials: Small studies usually involving 10-13 human subjects. They are primarily designed to detect any serious side effects. Drug development stops here if scientisits notice any significant side effects. These studies are usually “open label”, meaning all participants know what drug they’re taking; all subjects actually receive the drug.
3. Phase II trials: Involve 30-150 subjects and are designed to test a drug’s effectiveness in a somewhat preliminary fashion. These are frequently “double-blind”, meaning some participants receive the drug while others do not; neither subjects nor researchers know which patients receive the drug.
4. Phase III trials: Are pivotal – a successful outcome will normally result in FDA approval for use of the drug in any patient with the disease. These studies generally involve 250-500 participants. The trials are always double blind and often occur simultaneously at a number of centers. This phase takes two or more years to complete. Phase III trials must demonstrate that the treatment is effective and safe.
5. Post-marketing stage: Occurs when the drug is released for general use. This phase usually involves several thousand patients and is “open-label”. With this larger number of individuals, researchers may see side effects not detected in Phase III trials. Rare side effects do not attract notice until many individuals receive the therapy.
Phase I, II and III trials require substantial commitment from physicians and centers. Most studies require that participants regularly report to clinical centers for safety evaluations and tests to deteremine effectiveness.
Source: CSRO Magazine, Summer 2002, Volume 12, Issue 5