Journal Club Summary
Epi Lesson: Phases of a clinical trial
Clinical trials involving new drugs are classified into four phases with Health Canada and the FDA generally requiring a drug to have passed through Phase 3 before general approval. Phase 1 trials test the treatment in a small group of healthy people (20-80) to evaluate its safety, dosage range, and side effects. Phase 2 trials give the treatment to patients and in larger numbers (100-300) to evaluate effectiveness and safety. Phase 3 trials give the treatment to large groups of paitents (1,000-3,000) to confirm its effectiveness, monitor side effects, and compare to commonly used treatments. Phase 4 trials are post-marketing studies to determine additional information about side effects and risks. [2a trials studies focus on proving the hypothesized mechanism of action while the larger 2b trials seek to determine the optimum dose]
By: Dr. Ian Stiell