Clinical research is a branch of medical science that determines the safety and effectiveness of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatment, diagnosis or for relieving symptoms of a disease. The term clinical research refers to the entire bibliography of a drug/device/biologic, in fact any test article from its inception in the lab to its introduction to the consumer market and beyond.
Once the promising candidate or the molecule is identified in the lab, it is subjected to pre-clinical studies or animal studies where different aspects of the test article (including its safety toxicity if applicable and efficacy, if possible at this early stage) are studied. Phase 1 trials Phase 1 trials usually deal with investigating the studied drug in a minor number of research subjects who are healthy volunteers. This phase is mainly targeted at identifying the safety, tolerability, and the general mechanism of the action of the drug in humans.
These studies are usually conducted in tightly controlled clinics called CPUs (Central Pharmacological Units), where participants receive 24-hour medical attention and oversight. In some diseases in which the therapy under study is known to be too toxic for healthy subjects (some cancer medications, for instance), phase 1 trials are performed in patients with diseases to test these parameters.  Phase 2 trials The goal of phase 2 trials is to grasp additional understanding of the studied drug’s safety and efficacy.
It also determines the appropriate dose to be administered to deliver the desired treatment effect while minimizing the safety risk of future research subjects. This usually requires more than 100 patients to demonstrate relevant results, although the actual number of subjects varies widely based on the disease under study. Phase 3 trials Multiple phase 2 studies are often required to define the appropriate patient population to study during phase 3. Once the drug is deemed a potentially safe and effective candidate in Phase 2, it is then studied in Phase 3 trials.
This phase often exposes more than 1000 research subjects with the disease, and is usually performed at many clinics (sometimes well over 100) to enroll the trial (or trials). There is a focus on the effectiveness of the study drug in a variety of demographic and socioeconomic subjects with variants of the disease under study. A comparison is usually made with standard drugs available on the market. It is imperative that the drug is shown to be effective and safe in this phase.
When phase 3 trials are completed (as well as the data demonstrating safety and efficacy of the study drug), a New Drug Application (NDA) containing all manufacturing, pre-clinical, and clinical data is filed with the FDA for review. If deemed safe and effective, the FDA grants approval of the NDA, which then allows the company to market the product. This approval usually comes with strict requirements for the company to conduct additional studies to keep the NDA active (usually involving pediatric trials and additional safety trials).
 Phase 4 trials In phase 4, the aim is to further characterize the safety of the drug through the identification of unknown adverse reactions and to potentially research new therapeutic indications. Companies often use this phase to gain exposure to different physicians and clinics, which aids in the marketing of their product. The entire process of a drug from lab to market may take approximately 12 to 18 years (but not always), costing billions of dollars. PHARMACOVIGILANCE.
Pharmacovigilance (abbreviated PV or PhV) is the pharmacological science relating to the detection, assessment, understanding and prevention of adverse effects, particularly long term and short term side effects of medicines.  Generally speaking, pharmacovigilance is the science of collecting, monitoring, researching, assessing and evaluating information from healthcare providers and patients on the adverse effects of medications, biological products, herbalism and traditional medicines with a view to: •identifying new information about hazards associated with medicines •preventing harm to patients.
PHARMACOGENOMICS Pharmacogenomics is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug’s efficacy or toxicity. PHARMACOKINETICS Pharmacokinetics, sometimes abbreviated as PK, (from Ancient Greek pharmakon “drug” and kinetikos “to do with motion”; see chemical kinetics) is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism.
Pharmacokinetics includes the study of the mechanisms of absorption and distribution of an administered drug, the rate at which a drug action begins and the duration of the effect, the chemical changes of the substance in the body (e. g. by CYP or UGT enzymes) and the effects and routes of excretion of the metabolites of the drug. Pharmacokinetics may be simply defined as what the body does to the drug, as opposed to pharmacodynamics which may be defined as what the drug does to the body. PHARMACODYNAMICS.
Pharmacodynamics is the study of the biochemical and physiological effects of drugs on the body or on microorganisms or parasites within or on the body and the mechanisms of drug action and the relationship between drug concentration and effect. DOSE-RESPONSE RELATIONSHIP The dose-response relationship, or exposure-response relationship, describes the change in effect on an organism caused by differing levels of exposure (or doses) to a stressor (usually a chemical) after a certain exposure time. CLINICAL DATA MANAGEMENT SYSTEM A clinical data management system or CDMS is a tool used in clinical research to manage the data of a clinical trial.
The clinical trial data gathered at the investigator site in the case report form are stored in the CDMS. To reduce the possibility of errors due to human entry, the systems employ different means to verify the data. GOOD CLINICAL PRACTICES (GCP) Good Clinical Practice (GCP) is an international quality standard that is provided by International Conference on Harmonisation (ICH), an international body that defines standards, which governments can transpose into regulations for clinical trials involving human subjects.
Good Clinical Practice guidelines include protection of human rights as a subject in clinical trial. It also provides assurance of the safety and efficacy of the newly developed compounds. Good Clinical Practice Guidelines include standards on how clinical trials should be conducted, define the roles and responsibilities of clinical trial sponsors, clinical research investigators, and monitors. In the pharmaceutical industry monitors are often called Clinical Research Associates.