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What
are the different phases of human clinical trials that an experimental
drug for hair loss must pass through
There are 4 key phases within a human clinical trial that an experimental
drug must pass through before being accredited for use by the FDA
in the USA. European countries also require a similar process.
Phase I study: This is the earliest phase of drug development in
humans. This is usually a short term duration study of one to three
months It involves a small, well-controlled population of usually
healthy volunteers to establish the safety of the drug's use in
humans.
Phase II study: A study of short to medium duration (up to a six
months) using a larger number of drug takers. This phase is primarily
used to define dose and establish effectiveness of a drug for a
specific population and disease. Phase II studies are the first
to use patients with the disease or condition the drug is intended
for. The treatment trial is typically a randomized, well controlled,
double blind study.
Phase III study: The duration of phase three studies may last up
to several years for chronic diseases such as androgenetic alopecia.
The studies may involve several thousand individuals. The intention
is to demonstrate the drug is statistically effective against the
disease and to ensure it can be used safely for a prolonged period
of time.
Phase IV study: These studies are not conducted until after the
FDA has approved a drug product. These studies must be conducted
if the FDA approves the drug prior to the collection of all conclusive
premarketing data (e.g., "fast tracked" studies). Phase
IV may also be called post-marketing studies. These studies are
ongoing and may involve a range of age or ethnic groups. The data
derived from these studies may be used to support expanded claims
for approved drugs.
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