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TFC Clinical Research
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TFC Clinical research

Clinical research studies (sometimes called trials
or protocols) are a means of developing and
evaluating new treatments and/or medications for
specific types of diseases or other medical
conditions. There are many different types of
studies – some evaluate new surgical techniques or
instruments, some evaluate new ways of administering
medications that are already in common use, and some
evaluate new medications. Regardless of the type of
study, there are very strict rules for clinical
trials, which are typically monitored by the
National Institutes of Health and the U.S. Food and
Drug Administration, among other organizations. Most
of the research studies that we perform at Texas
Fertility Center involve promising new treatments
that we hope will directly benefit our patients.
When pharmaceutical companies or medical device
manufacturers develop promising new medications or
instruments, these new products are required to
undergo rigorous evaluation and testing before they
can be used for the general public. First, these
products are typically evaluated in very tightly
controlled laboratory experiments designed to detect
any obvious problems – such as defects in
manufacturing or production. They are then
frequently evaluated in animal studies, to confirm
that they are safe. Following the successful
completion of these studies, these products are
ready for human trials.
The primary goals of human studies are to establish
that new treatments are both safe and effective.
Once this has been confirmed, additional studies –
such as those designed to identify the optimal
dosing schedule for a new medication – are
performed. If the studies all support the
therapeutic benefit of the treatment, then the
sponsoring company will proceed with submission of
their data to the Federal Food and Drug
Administration (FDA) for approval. The FDA
submission and approval process is both time
consuming and expensive for product manufacturers.
They therefore spend a significant amount of time
and resources performing rigorous testing of all new
products prior to proceeding to the FDA, in order to
maximize the likelihood of approval.
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 I, II,
and III, it will usually be approved by the national
regulatory authority for use in the general
population. Phase IV are 'post-approval' studies.
Before pharmaceutical companies start clinical
trials on a drug, they conduct extensive
pre-clinical studies.
Phase I Trials
Phase I trials are the first stage of testing in
human subjects. Normally, a small (20-50) group of
healthy volunteers will be selected. This phase
includes trials designed to assess the safety (pharmacovigilance),
tolerability, pharmacokinetics, and pharmacodynamics
of a drug. These trials are often conducted in an
inpatient clinic, where the subject can be observed
by full-time staff. The subject who receives the
drug is usually observed until several half-lives of
the drug have passed. Phase I trials also normally
include dose-ranging, also called dose escalation,
studies so that the appropriate dose for therapeutic
use can be found. The tested range of doses will
usually be a fraction of the dose that causes harm
in animal testing. Phase I trials most often include
healthy volunteers. However, there are some
circumstances when real patients are used, such as
patients who have terminal cancer or HIV and lack
other treatment options. Volunteers are paid an
inconvenience fee for their time spent in the
volunteer centre. Pay for participation ranges from
a small amount of money for a short period of
residence, to a larger amount of up to approx $6000
depending on length of participation.
There are different kinds of Phase I trials:
SAD
Single Ascending Dose studies are those in
which small groups of subjects are given a
single dose of the drug while they are observed
and tested for a period of time. If they do not
exhibit any adverse side effects, and the
pharmacokinetic data is roughly in line with
predicted safe values, the dose is escalated,
and a new group of subjects is then given a
higher dose. This is continued until
pre-calculated pharmacokinetic safety levels are
reached, or intolerable side effects start
showing up (at which point the drug is said to
have reached the Maximum tolerated dose (MTD).
MAD
Multiple Ascending Dose studies are conducted
to better understand the pharmacokinetics &
pharmacodynamics of multiple doses of the drug.
In these studies, a group of patients receives
multiple low doses of the drug, while samples
(of blood, and other fluids) are collected at
various time points and analyzed to understand
how the drug is processed within the body. The
dose is subsequently escalated for further
groups, up to a predetermined level.
Food effect
A short trial designed to investigate any
differences in absorption of the drug by the body,
caused by eating before the drug is given. These
studies are usually run as a crossover study, with
volunteers being given two identical doses of the
drug on different occasions; one while fasted, and
one after being fed.
Phase II Trials
Once the initial safety of the study drug has
been confirmed in Phase I trials, Phase II trials
are performed on larger groups (20-300) and are
designed to assess how well the drug works, as well
as to continue Phase I safety assessments in a
larger group of volunteers and patients. When the
development process for a new drug fails, this
usually occurs during Phase II trials when the drug
is discovered not to work as planned, or to have
toxic effects.
Phase II studies are sometimes divided into
Phase IIA and Phase IIB.
- Phase IIA is specifically designed to assess
dosing requirements (how much drug should be
given).
- Phase IIB is specifically designed to study
efficacy (how well the drug works at the
prescribed dose(s)).
Some trials combine Phase I and Phase II, and
test both efficacy and toxicity.
Trial design
Some Phase II trials are designed as case
series, demonstrating a drug's safety and
activity in a selected group of patients. Other
Phase II trials are designed as randomized
clinical trials, where some patients receive the
drug/device and others receive placebo/standard
treatment. Randomized Phase II trials have far
fewer patients than randomized Phase III trials.
Phase III Trials
Phase III studies are randomized controlled
multicenter trials on large patient groups
(300–3,000 or more depending upon the
disease/medical condition studied) and are aimed at
being the definitive assessment of how effective the
drug is, in comparison with current 'gold standard'
treatment. Because of their size and comparatively
long duration, Phase III trials are the most
expensive, time-consuming and difficult trials to
design and run, especially in therapies for chronic
medical conditions.
It is common practice that certain Phase III
trials will continue while the regulatory submission
is pending at the appropriate regulatory agency.
This allows patients to continue to receive possibly
lifesaving drugs until the drug can be obtained by
purchase. Other reasons for performing trials at
this stage include attempts by the sponsor at "label
expansion" (to show the drug works for additional
types of patients/diseases beyond the original use
for which the drug was approved for marketing), to
obtain additional safety data, or to support
marketing claims for the drug. Studies in this phase
are by some companies categorized as "Phase IIIB
studies."
While not required in all cases, it is typically
expected that there be at least two successful Phase
III trials, demonstrating a drug's safety and
efficacy, in order to obtain approval from the
appropriate regulatory agencies such as FDA (USA),
or the EMEA (European Union), for example.
Once a drug has proved satisfactory after Phase
III trials, the trial results are usually combined
into a large document containing a comprehensive
description of the methods and results of human and
animal studies, manufacturing procedures,
formulation details, and shelf life. This collection
of information makes up the "regulatory submission"
that is provided for review to the appropriate
regulatory authorities[3] in different countries.
They will review the submission, and, it is hoped,
give the sponsor approval to market the drug.
Most drugs undergoing Phase III clinical trials
can be marketed under FDA norms with proper
recommendations and guidelines, but in case of any
adverse effects being reported anywhere, the drugs
need to be recalled immediately from the market.
While most pharmaceutical companies refrain from
this practice, it is not abnormal to see many drugs
undergoing Phase III clinical trials in the market.
Phase IV Trials
Phase IV trial is also known as Post Marketing
Surveillance Trial. Phase IV trials involve the
safety surveillance (pharmacovigilance) and ongoing
technical support of a drug after it receives
permission to be sold. Phase IV studies may be
required by regulatory authorities or may be
undertaken by the sponsoring company for competitive
(finding a new market for the drug) or other reasons
(for example, the drug may not have been tested for
interactions with other drugs, or on certain
population groups such as pregnant women, who are
unlikely to subject themselves to trials). The
safety surveillance is designed to detect any rare
or long-term adverse effects over a much larger
patient population and longer time period than was
possible during the Phase I-III clinical trials.
Harmful effects discovered by Phase IV trials may
result in a drug being no longer sold, or restricted
to certain uses.
In animal studies, to confirm that they are safe.
Following the successful completion of these
studies, these products are ready for human trials.
The primary goals of human studies are to establish
that new treatments are both safe and effective.
Once this has been confirmed, additional studies –
such as those designed to identify the optimal
dosing schedule for a new medication – are
performed. If the studies all support the
therapeutic benefit of the treatment, then the
sponsoring company will proceed with submission of
their data to the Federal Food and Drug
Administration (FDA) for approval. The FDA
submission and approval process is both time
consuming and expensive for product manufacturers.
They therefore spend a significant amount of time
and resources performing rigorous testing of all new
products prior to proceeding to the FDA, in order to
maximize the likelihood of approval.
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