2. INTRODUCTION
Clinical trial is a systematic investigation in human
subjects for evaluating the safety and efficacy of
any new drug.
WHO definition: “Any research study that
prospectively assigns human participants or groups
of humans to one or more health-related
intervention to evaluate the effects on health
outcomes”.
3. PRE CLINICAL TRIALS
After synthesizing/identifying a prospective compound, it is
tested on animal to expose the whole pharmacological profile.
Experiment are generally performed on a rodent (mouse, rat,
guinea pig hamster, rabbit) and then on larger animal(cat, dog,
monkey)
The following types of taste are performed:-
Screening test: For analgesic and hypoglycaemic activity
Tested on isolated organ, bacterial culture: For antihistaminic, anti
secretory, vasodilator, antibacterial, etc
Confirmatory test and analogous activities: For antipyretic and
anti-inflammatory activity
Systemic pharmacology: For study of Primary action of drug,
Mechanism of action
Toxicity test: The aim to determine the safety of compound,etc
4. WHY DO WE NEED CLINICAL TRIALS?
Clinical trial are essential to the development of new
intervention. For example, without clinical trial we can’t
properly determine whether new medicine developed in the
laboratory or by animal models are effective or safe. This is
because computer simulation and animal testing can only tell
us so much about how a new treatment might work and are no
substitute for testing in living body
Clinical trial also permit testing and monitoring of the effect of
an intervention on a large number of people to ensure that any
improvement as a result of the intervention occurs for many
people and is not just a random effect for a one person.
Clinical trials can also help to improve health care service by
raising standard of treatment .
6. PHASE I
HUMAN PHARMACOLOGY AND SAFETY
First stage of testing in human subjects.
Design to assess the safety, tolerability, pharmacokinetic,
pharmacodynamics of drug and to detect any potentially
dangerous effect on vital function.
The aim of phase 1 trial is to determine the maximum tolerated
dose (MTD) of new drug.
20-80 healthy volunteers.
Duration: 6-12 months.
These trials are often conducted in an inpatient clinic, where the
subject can be observed by full-time staff.
7. PHASE II
THERAPEUTIC EXPLORATION AND DOSE RANGING
To determine the therapeutic efficacy and range of doses.
Design to assess how well drug works.
To confirm effectiveness, monitor side effect, and further
evaluate safety.
100-300 healthy volunteers.
Duration: 6 months to several years.
8. PHASE III
THERAPEUTIC CONFIRMATION/COMPARISON
Therapeutic exploratory trials.
Large scale, multicentre, randomised, controlled trials.
To assess overall and relative therapeutic value of the new
drug, efficacy, safety and special properties.
To determine optimal dose schedule for use in general.
Target population: 1000’s to 3000 patients
Duration: up to 5 years
9. END OF CLINICAL TRIAL ACTIVITIES
Sponsor: Expert committee review of efficacy, safety and
potential sales.
Go decision to file new drug application with DCGI (Drug
Controller General of India).
Expert review by DCGI’s Committee.
DCGI approval
NCE marketed Phase 4 begins
10. NDA: NEW DRUG APPLICATION
NDA refers to New Drug Application.
Formal proposal for FDA/DCGI to approve a new drug for
sale.
Sufficient evidence is provided to FDA/DCGI to establish.
Drug is safe and effective
Benefits outweigh the risk.
Proposed labelling is appropriate.
NDA contains all of the information gathered during preclinical
to phase III
NDA can be thousand of pages long
Can take 2-3 years for FDA to review.
11. PHASE IV
POST-MARKETING SURVEILLANCE
Done after drug has been marketed.
Confirm the efficacy and safety profile in large
populations during practice.
Helps to detect ADRs, Drug Interaction.
Also to explore new uses for drugs.
Evaluation of over-dosage.
No fixed duration and patient population.
Dose refinement: Evaluation of new formulation,
dosages, duration of treatment.