How does research work?
Research into skin conditions goes on worldwide every day. Research follows prescribed conditions to ensure results are valid and trustworthy.
Phases I and II Trials
Phase 1 studies assess the safety of a drug or device
This initial phase of testing, which can take several months to complete, usually includes a small number of healthy volunteers (20 to 100)
The study looks at the effects of the drug including how it absorbed, metabolized, and excreted
It also investigates the side effects that occur as dosage levels are increased
About 70% of experimental drugs pass this phase of testing.
Phase II studies test the efficacy of a drug or device
This second phase of testing can last from several months to two years
It can involve up to several hundred patients who have the relevant condition
Most phase II studies are randomized trials where one group of patients receives the experimental drug, while a second "control" group receives a standard treatment or placebo
The studies may also be "blinded" which means that neither the patients nor the researchers know who has received the experimental drug
About one-third of experimental drugs successfully complete both Phase I and Phase II studies.
Phase III and IV Trials
Phase III studies involve randomized and blind testing in several hundred to several thousand patients
This large-scale testing, which can last several years, provides the pharmaceutical company with a more thorough understanding of the effectiveness of the drug or device, the benefits and the range of possible adverse reactions
70% to 90% of drugs that enter Phase III studies successfully complete this phase of testing
Once Phase III is complete, a pharmaceutical company can request approval for marketing the drug
Phase IV studies are conducted after a drug or device has been approved for consumer sale
Pharmaceutical companies have several objectives at this stage:
(1) to compare a drug with other drugs already in the market;
(2) to monitor a drug's long-term effectiveness and impact on a patient's quality of life; and
(3) to determine the cost-effectiveness of a drug therapy relative to other traditional and new therapies
Phase IV studies are not used for all drugs or devices