Clinical trials involve research studies on human volunteers to determine the effectiveness and safety of drugs or devices. There are five phases of clinical trials: pre-clinical studies in animals; Phase 0 microdosing studies in 10-15 humans; Phase I safety trials in 20-80 humans; Phase II efficacy trials in several hundred humans; Phase III large randomized controlled trials in 300-3,000 humans to compare to standard treatment; and Phase IV post-marketing surveillance trials to monitor adverse effects.

1. CLINICAL TRIALS
&
PHASES OF CLINICAL TRIALS
Ms.VARALAKSHMI
MSc DCR

2. What are clinical Trials
• Research study on human volunteers
• To determine the effectiveness and safety of a
drug or device in humans.

3. Types of clinical Trials
 The U.S. National Institutes of Health (NIH) organizes trials into
five different types
 Treatment Trials
Test experimental treatments, new combinations of drugs, or new
approaches to surgery.
 Prevention Trials
Look for better ways to prevent disease in people.
 Diagnostic Trials
Conducted to find better tests or procedures for diagnosing a
particular disease or condition.
 Screening Trials
Test the best way to detect certain diseases or health conditions.
 Quality of Life
Explore ways to improve comfort and the quality of life for
individuals with Serious medical conditions.

4. PHASES OF CLINICAL
TRIALS
Pre-clinical studies
Phase 0
Phase I
Phase II
Phase III
Phase IV

5. Pre Clinical Studies
• Involve in vitro (test tube or laboratory)
studies and trials on animal populations.
• Wide ranging dosages of the compounds are
introduced to the animal subjects or to an in
vitro substrate.
• Obtain preliminary efficacy , Toxicity and
pharmacokinetic information.

6. Phase 0
• This is also known as Human micro dosing
studies
• Which includes the administration of single
sub therapeutic doses of the study drug to a
small number of subjects (10-15)
• Gather the preliminary data about
pharmacokinetic and pharmacodynamics

7. Phase - I
• First stage of testing in humans.
• Researchers look for safety and potentially harmful side
effects.
• Usually include only a limited number of human subjects
(20-80)
• This phase of testing usually takes several months.
• Three different kinds of Phase I trials include:
– SAD-single ascending dose studies
– MAD-multiple ascending dose studies
– Food Effect-investigates differences in absorption

8. Phase - II
• Performed on larger groups – usually involve
several hundred.
• Designed to assess how well the drug works.
• Most of these trials are randomized trials
• Phase IIA – designed to assess dosing
requirements (How much drug should be
given)
• Phase IIB – designed to study efficacy (How
well the drug works at the prescribed level).

9. Phase - III
• Randomized control trials on large patient groups
(300-3000).
• These trials are typically multi-center trials.
• Many phase III trials are randomized and blinded.
• Compare the results of the patients on the
experimental trial to those patients utilizing
standard diagnostic studies or treatment.
• Studies move into this phase only after a
diagnostic agent, have shown promise in phase I
and II trials.

10. Phase - IV
• Post marketing Surveillance.
• This involves safety surveillance.
• Adverse effects detected by Phase IV trials
may result in withdrawal or restriction of a
drug.