ClinicalTrials.gov is a registry and results database of publicly and privately supported research studies conducted in the United States and around the world. Sponsors or investigators of certain clinical trials are required by U.S. law to register their trials on, and submit summary results to, ClinicalTrials.gov. Source: Clinicaltrials.gov: For Researchers
This is a good place to search to see what studies may be being done on either the disorder you are looking at or the drug/device you are researching. You can also see what trials are being conducted by the company of your choice.
Phase 0: Exploratory study - very limited human exposure to the drug, with no therapeutic or diagnostic goals
Phase 1: Studies emphasizing safety. Usually conducted with healthy volunteers. Goal - what are the most frequent and serious adverse events and, often, how the drug is metabolized and excreted.
Phase 2: Studies that gather preliminary data on effectiveness. Participants receiving the drug may be compared with similar participants receiving a different treatment, usually an inactive substance (called a placebo) or a different drug. Safety continues to be evaluated, and short-term adverse events are studied.
Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.
Phase 4: Studies occurring after FDA has approved a drug for marketing. These including postmarket requirement and commitment studies that are required of or agreed to by the sponsor. These studies gather additional information about a drug's safety, efficacy, or optimal use.
Not Applicable: Used to describe trials without FDA-defined phases, such as trials of devices or behavioral interventions.
Drug patents expire over time, letting other pharmaceutical manufacturer's produce generic, cheaper versions of the drug. This effects the profits of pharmaceutical companies and is of great interest to investors.
Medicines are often paired with devices to administer them (think asthma inhalers). Patents generally last 20 years, but can be extended in cases such as a patent was issued, but FDA approval took several more years to obtain.
