AN INTRODUCTION OF CLINICAL TRIALS
What is Clinical Trials?
Clinical trials are forthcoming biomedical or behavioral research studies on human subjects (Patients / Healthy humans) that are intended to respond specific questions about biomedical or behavioral interventions (new vaccines, drugs, treatments, dietary supplements, devices or new ways of using known interventions), generating safety and efficacy data.
What is the Phase of clinical Trials?
Clinical trials involving new drugs are commonly classified into four phases. Each phase of the drug approval process is treated as a separate clinical trial. The drug-development process will normally proceed through all four phases over many years. If the drug successfully passes through Phases
1. Phase 0: Pharmacodynamics & Pharmacokinetics
2. Phase 1: Screening for safety
3. Phase 2: Establishing the efficacy of the drug, usually against a placebo
4. Phase 3: Final confirmation of safety and efficacy
5. Phase 4: Sentry studies during sales
Each phase has a different purpose and helps scientists answer a different question:
Phase 0 trials are the first-in-human trials. Single sub therapeutic doses of the study drug are given to a small number of subjects (10 to 15) to gather preliminary data on the agent’s pharmacodynamics (what the drug does to the body) and pharmacokinetics (what the body does to the drugs).
Phase 1 trials, researchers test an experimental drug or treatment in a small group of people (20–80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2 trials, the experimental treatment is given to a larger group of people (100–300) to see if it is effective and to further evaluate its safety.
Phase 3 trials, the treatment is given to large groups of people (1,000–3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow it to be used safely.
Phase 4 trials, post marketing studies delineate additional information, including the treatment’s risks, benefits, and optimal use.
Before pharmaceutical companies start clinical trials on a drug, they conduct extensive preclinical studies.