Clinical trials are research studies conducted on humans to evaluate the effectiveness and safety of new medical strategies, drugs, treatments or devices. There are two main types of clinical trials - interventional which administer treatments to participants, and observational which observe existing treatments. Clinical trials progress through four phases, starting with small safety trials in Phase I and increasing in size up to Phase III which confirm effectiveness in large groups. Phase IV trials continue after approval to further monitor risks, benefits and optimal use. Clinical trials must follow strict protocols, obtain informed consent, approval from ethics committees and be registered and reported according to guidelines.

1. A GUIDE TO UNDERSTANDING
CLINICAL TRIALS
(PART 1 – THE BASICS)

2. What will you learn from these slides?
What are clinical trials?
What are clinical trials?
Types of clinical trials
Phases of clinical trials

3. What are clinical trials?
Clinical trials refers to research conducted on humans
that is designed to evaluate the effectiveness of a drug or
treatment and add to medical knowledge
Source: A young researcher's guide to a clinical trial

4. Clinical trials as defined by NIH*
*NIH: National Institutes of Health, USA
Source: What are clinical trials?
Clinical trials are research studies that explore
whether a medical strategy, treatment, or device is
safe and effective for humans. These studies also
may show which medical approaches work best
for certain illnesses or groups of people.

5. Human subjects volunteer
to participate in them
Typically last for about
5-7 years
*First, a new medical strategy, drug, treatment, or device is developed in the lab, then
it is tested on animals, and finally tested on humans to see how safe or effective it is.
Cannot be conducted
without the approval of
relevant governing and
ethical committees
Usually medical studies
Constitute the last
step of the research
process*
Investigations are
conducted following
a pre-determined
research protocol
What are the characteristics of clinical trials?

6. What are the types of clinical trials?
There are two types of clinical trials:
1. Interventional:
• Specific treatments or interventions are given to the participants by the
investigators.
• The outcomes are then compared to a group that has been given a
different treatment or no treatment.
• The investigators or the researchers observe the treatments or
management techniques that are given to a group of patients and
note the outcomes.
• But the researchers do not administer the interventions in this case.
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2. Observational:

7. More trials types defined by the NIH
Test new treatments,
combinations of drugs, surgical
approaches, or radiation therapy
Find ways to prevent diseases;
include medicines, vaccination,
or lifestyle change
Test the best way to detect
specific diseases or health
conditions
Come up with better tests or procedures
for diagnosing a disease or health
condition
Explore ways to improve the comfort and quality
of life of people with a chronic illness
(also known as supportive care trials)
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8. What are the phases of clinical trials?
Clinical trials are conducted in several phases and each phase has a different purpose.
PHASE I TRIALS
A new drug or treatment is tested on a small
group of people (20–80)
Purpose
To evaluate its safety and identify the side
effects, and to obtain early signs of
effectiveness
PHASE II TRIALS
The drug or treatment is given to a larger
group of people (100–300)
Purpose
To evaluate its effectiveness and obtain more
information about the side effects and risks
of the treatment
PHASE III TRIALS
The drug or treatment is administered to
very large groups of people (1,000–3,000)
Purpose
To confirm its effectiveness, compare it with
other modes of treatment, and evaluate the
overall risk-benefit equation
PHASE IV TRIALS
These studies are conducted after the drug’s
approval and launch in the market (also
called post-marketing surveillance studies)
Purpose
To obtain additional information about its
risks, benefits, and optimal use

9. We hope you found this useful.
Here’s a list of topics we will cover in Part 2:
• Protocols to be followed during clinical trials
• Informed consent from subjects
• Approval for trials
• Registration of trials
• Reporting guidelines for trials
• Manuscript structure of a clinical trial

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