Clinical trial phases 3,4,5 By Danish Ibrahim Jasnaik
Submitted to: Lijin Sir
Clinical trials are sets of tests in medical research and drug
development that generate safety and efficacy (In medicine,
efficacy indicates the capacity for therapeutic effect of a
given intervention data for health interventions e.g., drugs,
diagnostics, devices, therapy protocols). They are conducted only
after satisfactory information has been gathered on the quality
of the nonclinical safety, and health authority/ethics committee
approval is granted in the country where approval of the drug or
device is sought.
• Randomized control trials on large patient groups
• Comparative studies to verify the effectiveness
of diagnostic, therapeutic, or prophylactic drugs,
devices, or techniques determined in phase II
• Studies move into this phase only after a
diagnostic agent, modality, or treatments have
shown promise in phase I and II trials
• Many phase III trials are randomized and blinded.
Randomization means Researchers assign
patients by chance to either a group taking the
new diagnostic or treatment agent. Similar to
“flipping a coin”.
Example: Patient #1 is assigned to Arm A of
the trial, which involves the new treatment.
Patient #2 is assigned to Arm B, which is the
Blinded study means, the patient does
not know which arm of the protocol
they have been assigned to.
Example: Patients who know that they
are assigned to the “new treatment”
group might expect it to work better and
report hopeful signs because they want
to believe they are getting well. This
could bias the study by making results
look better than they are.
• Pre-approval, post-launch
• Involve safety surveillance and ongoing
technical support of a drug.
• Sometimes mandated by the FDA for
additional testing including interactions
with other drugs and testing on certain
• Not all Phase IV studies are post-marketing surveillance (PMS) studies
but every PMS study is a phase IV study
• Adverse effects detected by Phase IV trials may result in withdrawal or
restriction of a drug -
Examples include Vioxx (used in the treatment of arthritis and other
conditions causing chronic or acute pain. On September 30, 2004, Merck
withdrew rofecoxib from the market because of concerns about
increased risk of heart attack and stroke associated with long-term,
Phase V is a growing term in the literature of
research to refer to community-based
research, it is used to signify the integration of
a new clinical treatment into widespread
public health practice.