CONDUCT OF A DRUG TRAIL IN
DRUG TRAIL IN CVS
• Core elements
– Study population, enrollement, recruitment, randomisation,active drug.
– Phases of trails
– Data collection & statistical analysis
• Consort statement.
• Despite many decades of advances in diagnosis and management,CVD
remains the leading cause of death in developed & developing countries.
• Therapeutic recommendations in cardiovascular medicine are no longer
based on nonquantitative pathophysiologic reasoning but instead are
• The practice of evidence-based medicine occurs when clinical decision
making involves the incorporation of the best avail-able research evidence
together with the clinician‘s expertise and consideration of local or
individual circumstances and the patient‘s preferences regarding therapies
• One needs to be able to efficiently sift through the evidence and then be
able to appraise the quality of that evidence before deciding how much
weight to give it in terms of clinical decision making.
• Thus, the design, conduct, analysis, interpretation, and presentation of
clinical trials are a central feature of the professional life of the
contemporary cardiovascular specialist
• A clinical trial is defined as a prospective scientific experiment that
involves human subjects in whom treatment is initiated for the evaluation
of a therapeutic intervention.
• The Code of Federal Regulations (CFR) defines a clinical trial as the
clinical investigation of a drug that is administered or dispensed to, or used
involving one or more human subjects
Historical Highlights of Drug
• 1909: Paul Ehrlich -
• 1929: Alexander Fleming -
• 1935: Gerhard Domagk -
• 1944: Schatz/Bugie/Waksman –
• By 1950, the British Medical Res.
Council developed a systematic
methodology for studying &
DIFFERENT TYPES OF CLINICAL TRIALS BASED ON
• TYPE OF STUDIES BY THE WAY THE RESEARCHERS BEHAVE
– Case report
– Case series
– Cross-sectional (survey)
– Prospective, observational (cohort)
– Randomized, clinical trial (RCT)
• The 3 most common designs are
– uncontrolled clinical trials- weakest level
– nonrandomized controlled trials, and
• For uncontrolled trials, no concurrent comparison group exists .
• In nonrandomized controlled trials, a concurrent comparison group does
exist, but patients are allocate to this group by a nonrandom process.
• In an RCT, individuals are randomly allocated to 2 or more treatment
groups, which usually include a standard treatment group and one or more
Classification by Study Design
• Advantages of Clinical Trials
• Overall, clinical trials serve a multitude of functions that
– determination of a maximum tolerated dose,
– formulation of the basis for drug approval by the FDA,
– definition of standard therapeutic management.
– Often provides the strongest evidence in support of cause-effect
– Basis for clinical and public health policy
• Examples of clinical trial goals include assessing the safety and (relative)
effectiveness of a medication or device:
– On a specific kind of patient .
– At a different dose (e.g., 10-mg dose instead of 5-mg dose)
– For a new indication
– Is more effective for the patient's condition than the standard therapy
– Relative to two or more already approved/common interventions for
that disease .
• Small but important effect
• potential for increased recruitment
and Enhance generalizability of
• extensive quality control
• contributions of multiple
investigators with complementary
• Bring new treatment to the
• relate primarily to cost and to
logistical aspects of coordinating
research across multiple units.
• SINGLE-CENTER TRIALS
tend to be less expensive and
cumbersome than multicenter
trials, but the center must assume
responsibility for all aspects of
trial conduct, including quality
control,data management, and
• Sample size difficult.
Why Multicenter Trials?
DRUG TRAIL IN CVS
Case-control studies and registry observations are integral to epidemiologic and
outcomes research, are not strictly clinical trials, and so will not be included
GCP Guidelines- International Conference on Harmonization
• The objective of ICH GCP Guidelines is to provide a unified standard for
European Union, Japan and United States to facilitate the mutual
acceptance of clinical data by the regulatory authorities in the jurisdiction.
• Published by the FDA in Federal Register in May, 1997
• Adopted by all parties as GCP standard (considered law in European
Union; considered ―final guidance‖ in the US)
• Based on the Declaration of Helsinki
• This regulatory harmonization is achieved by developing guidelines. These
guidelines are divided into four categories as follows:
– Q – Quality Guidelines: Defining relevant thresholds for impurities testing and
a more flexible approach to pharmaceutical quality based on Good
Manufacturing Practice (GMP) risk management.
– S – Safety Guidelines: ICH has produced a comprehensive set of safety
guidelines to uncover potential risks like carcinogenicity, genotoxicity and
– E – Efficacy Guidelines: The work carried out by ICH under the Efficacy
heading is concerned with the design, conduct, safety and reporting of clinical
– M – Multidisciplinary Guidelines: Those are the cross-cutting topics which do
not fit uniquely into one of the Quality, Safety and Efficacy categories. It
includes the ICH medical terminology (MedDRA) and the Common Technical
CLINICAL TRIAL IN INDIA
• India became a member of WTO in 1995 and agreed to adhere to Product &
Process Patent regime from 2005.
• India provides excellent environment for CT:
– in terms of Less Cost,
• Around 25 contract research organisations (CROs) and almost all
multinational pharmaceuticals companies have started full-fledged clinical
trials in India since last three years.
• Further, the amendment to Schedule Y of the Drugs and Cosmetics Act in
February 2005 , now allows MNC s to conduct simultaneous trails in India
• TRIAL REGULATIONS IN INDIA
• DCGI under CDSCO has the Prime responsibility for Regulating CTs in
• Indian GCP Guidelines are in line with WHO, ICH, USFDA, and European
GCP Guidelines as well as ICMR Code.
• Drugs & Cosmetics Act 1940, & Schedule Y tells the requirement and
guidelines on Clinical Trials for Import & Manufacture of New Drug in
• ICMR code includes statement of general & specific principles on research
using human subjects in biomedical research.
GOOD CLINICAL PRACTICE
Elements of GCP
• Investigator Brochure
• Essential documents
• Clinical trial protocol and protocol amendments
SPONSORS FOR CLINICAL TRIALS
• takes the responsibility for the Initiation, Management, and/or financing the
– Pharmaceutical and Biotechnology companies – which must prove the
safety and effectiveness of their medicines before they can be marketed
– National Institutes of Health (NIH) – which are funded by the US
– Other government agencies.
– University Medical Schools & Hospitals, or any other medical research
– Some non-profit organizations and even individual or group of
• CRO is the Organization Contracted by the Sponsor to Perform One or
More of Sponsor‘s Trial related Duties and Functions.
• Investigator is responsible for the Conduct of a Clinical Trial at a Site
Qualified to perform study should have Appropriate education, training and
experience to assume responsibility and should provide evidence of such
• For investigational drug trials
• Summary of significant physical, chemical, pharmaceutical,
pharmacological, toxicological, pharmacokinetic, metabolic, and clinical
information that is relevant to the investigational product
• Relevant animal and clinical studies, adverse events, etc.
• Ethics Committee ensures prtection of Rights, Safety, and Wellbeing of the
Subjects involved and to provide Public Assurance of the Protection
• Study Subjects ( Patients ) are Individual who Participate in the Study
• The researchers send the data to the trial sponsor, who then analyzes the
pooled data using statistical tests.
• ESSENTIAL DOCUMENTS
• Essential Clinical Trial Documents individually and collectively evaluates
the conduct of a Trial & Preserves the integrity of the Data.
• These Documents demonstrate the Compliance of the Investigators and
Sponsors/ CRO with GCP & all applicable Regulatory Requirements.
• They include, Base Records, Laboratory Data, CRFs, Randomization Key,
Other Investigational Records, EC-NOC, DCGI-NOC, ICF, CRO-Sponsor
• Institutional Review Boards [IRBs]/IEC
• Rely on integrity of Investigator but outside groups also have oversight
• Participants‘ rights protected by [IRBs]/IEC
o An IRB is defined as: "any board, committee or other group formally
designated by an institution to review, to approve the initiation of, and
to conduct periodic review of biomedical research involving human
IRB/IEC responsible for such tasks:
• Develop and issue written procedures
• Review research for risk/benefit analysis & proper protection of
• Issue written notice of approval/disapproval to the Investigator
• Review and respond to proposed protocol changes submitted by the
• Review reports of deaths, and serious and unexpected adverse events
received from the Investigator
• Conduct periodic continuing review of the study, study risks, selection
of subjects, privacy of subjects, confidentiality of data, and the consent
REVIEW OF ETHICS COMMITTEE OPERATIONS
• EC must have written SOP on its Compositions, Functions &
• The Chairman of EC should be from outside of the Institution (
Non Affiliated member ).
• The Quorum of EC should have min. 5 Members ( Medical
Scientist / Pharmacologist, Clinician, Social Scientist , Legal
Expert, Lay person. )
• No CT should be initiated at any Site without obtaining written NOC from
the respective EC.
• If any Investigator or Study team Member is a part of EC, they should
abstain from voting on their research proposal
• All serious & unexpected ADR should be reported to EC within 7 working
days of their occurrence.
• EC should maintain its records for at least 5 years after the completion /
termination of the study
• Equipoise is an ethical concept in the design and conduct of clinical trials.
• we can only conduct clinical trials in areas of uncertainty and can only
continue as long as the uncertainty remains.
• Thus, for an RCT it is unethical to initiate a clinical trial that does not
include the ―standard treatment‖ as 1 of the therapy arms, if such a standard
exists, and it is unethical to include a therapy arm that is known to be
inferior to any other treatment.
3 ethical principles guide clinical research:
• Respect for Persons: Treatment of person as autonomous
• Beneficence: Issue re: potential conflict between good of society vs.
• Justice: Treatment of all fairly & all equally share benefits & risks
Ethics of Clinical Trials:Protection of Participants
• Voluntary informed consent
• Experiment must be for the good of society, & results not obtainable by
• Experiment should be based upon prior animal studies
• Physical & mental suffering & injury should be avoided
• No expectation that death/disabling injury will occur from the experiment
• Risk vs. benefit
• Only scientifically qualified persons to be involved
• Subject can terminate her/his involvement
10 Key Points
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• ADMINSTRATIVE STUCTURE
• steering committee: usually is made up of a study chair and other selected
(or elected) representatives from the investigators and sponsor.
• Steering committee members develop the protocol, lead the trial, and
publish the results when the trial is complete.
• Data coordination center is responsible for the management and quality
control of the trial data, as well as for interim or final analyses of the results
and monitoring safety, and efficacy data
STUDY TEAM AT TRIAL SITE
• Study Team at Trial Site include Investigator, Co-Investigator, Study
Coordinator, Nurse, Pharmacist.
• Unblinded Personnel (Coordinator/Nurse/Pharmacist) are required in blinded
Trials for dispensing the Trial Medications to the Study Subjects
• Clear delegation of duties to the study team members is essential for the
smooth execution of a clinical Trial.
Individual Member of the Study Team can be delegated
specific Trial Duties such as:
• Administration of ICF
• Recruitment of Subjects
• Correspondence with EC / CRO / Sponsors
• Stoarge, Dispensing & Accountability of Drugs
• Completion of Source Documents
• Completion of CRF
• Medical Management of the Trial Subject
• Reporting of SAE ( Adverse Events )
• Escalations, Resolutions, Management of Deviations
• Logistics Management
• Resolution of Data Enquiries
• Patient‘s Visit Scheduling, Protocol Compliance & Follow Up
• Maintenance of Site Master File.
• Compliance with GCP & Regulatory Guidelines
• Tracking of Payments / Study Grants
Idea OF new drug
Reviews from the experts(Sponsor or CRO)
First planning meeting (basic design features)
Second planning meeting (draft protocol)
Final protocol (ethical and scientific, signed by a statistician)
Evaluation (scientific review, IRB, funding)
Final analysis and publication
Development of a Clinical Trial
• A pilot experiment, also called a pilot study,
• A small scale preliminary study conducted in order to evaluate feasibility,
time, cost, adverse events, and effect size (statistical variability) in an
attempt to predict an appropriate relevant sample size and improve upon
the study design prior to performance of a full large-scale quantitative
• To avoid time and money being wasted on an inadequately designed
Core Elements of a Clinical Trial
• Research Question
• Hypotheses-Clinical Relevance
• Core Design
• Study Participants
• Masking (Blinding)
• Treatment Groups
• Analytical Issues-Statistical Methodology
• Interpretation of Results
• 1.Constructing the Research Question
• A hypothesis is the best guess as to what the answer to the study question
might be. It should ideally be based on knowledge of the published
literature and preliminary work and, hence, be an informed guess.
• FINER Criteria for a Good Research Question
• Feasible Interesting Novel Ethical Relevant
Core Elements of a Clinical Trial
• The hypothesis
• Regardless of the design of the trial, it is essential that investigators provide
a statement of the hypothesis being examined, using a format that permits
biostatistical assessment of the results
• Typically, a null hypothesis (HO) is specified (e.g., no difference exists
between the treatments being studied) and the trial is designed to provide
evidence leading to rejection of HO in favor of an alternative hypothesis
(HA; a difference exists between treatments).
• Selection of Endpoint of Clinical Trial -Two major approaches
• net clinical benefit, net clinical outcome, or NACE
• The balance of benefit and risk associated with a new treatment may be
• Such terms typically combine elements of efficacy and safety (e.g.,
cardiovascular death, nonfatal myocardial infarction [MI], nonfatal stroke,
nonfatal major bleed) and provide clinicians with a summary statement
about what to expect from a new treatment
• surrogate endpoint
• Another approach is to use a a substitute for measuring more traditional
• Surrogate endpoints are attractive to investigators because they are often
measured on an interval (continuous) scale and can lead to trials with a
smaller sample size
• CLINICAL TRIAL PROTOCOL
• The protocol is the trial's 'operating manual' and ensures that all researchers
perform the trial in the same way on similar patients and that the data is
comparable across all patients.
• Because the trial is designed to test hypotheses and rigorously monitor and
assess outcomes, they can be seen as an application of the scientific
method, specifically the experimental step.
• 4-50 pages long
• Written agreement between:
– the investigator
– the participant,
– and the scientific community
• Legal documents for
– FDA and other regulatory bodies
• To procure funding
Functions of Clinical Trial Protocol
• Study Participants-
• Ideal ‗Accessible‘ Population
– high risk for disease
– candidates for treatment
– representative of target population
– feasibility considerations
• high quality data
• Sample size:
• Larger the sample size (the larger the n), the more confident we will be in
trusting the conclusion
• Effect of a particular intervention being studied is very small, a large n
would be needed to be certain of detecting it.
• Calculation of sample size-based on anticipated event rates in study
population and clinically relevant differences in rates anticipated between
two arms of trial.
• Enrollment Criteria
• – characteristics of accessible population
– – considerations related to:
– • adherence to therapy
– • follow-up
– • safety
– • ethics
• Most challenging
• From an accessible population,
which is a subset of the target
• They also must secure approval
from their institutional review
board for their recruitment plans.
• In most trials, the number of
contacted people who actually
enroll is small.
DRUG TRAIL IN CVS
• Informed consent
• Informed consent is a legal process in which a recruit is instructed about
key facts before deciding whether to participate. Researchers explain the
details of the study in terms the subject can understand. The information is
presented in the subject's native language.
• The document includes details such as its purpose, duration, required
procedures, risks, potential benefits and key contacts.
• The participant then decides whether to sign the document.
• The document is not a contract, as the participant can withdraw at any time
Note: It is assumed that all patient entering the run-in
period are eligible and have given consent
• A scientifically valid comparison between 2 treatment groups depends on
the groups being alike as much as possible, with the only exception being
the specific treatments under investigation.
• The best way to achieve such a balance is by the use of randomization in
which a chance mechanism determines the treatment assignment.
• Randomization will ensure that a specific treatment assignment is not
known in advance to either the clinician or the patient.
• Randomization has 3 important influences that explain why it is considered
the standard for trial design:
• (1) it reduces the likelihood of patient selection bias that may occur either
consciously or unconsciously;
• (2) it enhances the likelihood that comparable groups of subjects are
compared, especially if the sample size is sufficiently large; and
• (3) it validates the use of common statistical tests such as the x2 test for
comparison of proportions and Student‘s t test for comparison of means.
• Only when both the patient and caregiver are unaware of the treatment
assignment can their desire for a favorable outcome not potentially bias the
results of the trial..
• Selection of Active Treatment and Dosage
• Before a company initiates testing in humans), it must conduct extensive
experiments in animal and human cells and in live animals (Preclinical
• If this stage of testing is successful, the company files an Investigational
New Drug (IND) application with the Food and Drug Administration
(FDA) to request permission to conduct clinical trials.
• Selection of dosage is an inexact science, often driven by phase 1 or 2
dose-response studies followed subsequently by results of phase 3 trials.
• Phase I
• These trials are designed to obtain the following information:
– Safety – Determine the most significant adverse events in human
– Tolerability – The safe dose range is determined by dose escalations .
– Pharmacokinetics –the effects body on the drug molecule
– Pharmacodynamics – The effects of the drug on the body
• The tested range of doses will usually be a fraction of the dose that caused
harm in animal testing. Phase I trials most often include healthy
• Types of Phase 1 trials:
– SAD – Single Ascending Dose
– MAD – Multiple Ascending Dose
– Food Effect – Effects of food substances on the absorption of the drug
Single ascending dose
• Based on tradition, not so much on statistical theory
• Dose escalation to reach maximum tolerated dose (MTD)
• Dose escalation often based on Fibonacci Series
1 2 3 5 8 13 . . . .
Phase I Design
1. Enter 3 patients at a given dose
2. If no toxicity, go to next dosage and repeat step 1
3. a. If 1 patient has serious toxicity, add 3 more
patients at that does (go to 4)
b. If 2/3 have serious toxicity, consider MTD
4. a. If 2 or more of 6 patients have toxicity, MTD reached (perhaps)
b. If 1 of 6 has toxicity, increase dose and go back to step 1
Designed to find dose where 1/3 of patients experience dose limiting
Standard escalation design tends to underestimate target dose
• Multiple ascending dose
• Multiple ascending dose studies are conducted to better understand the
pharmacokinetics and 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 acquire information on how the drug is processed
within the body.
• The dose is subsequently escalated for further groups, up to a
• Phase II
• Once range of doses is determined, the next goal is biological activity or
• Phase II trials are performed on larger groups (100-300) 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.
• Genetic testing is common, particularly when there is evidence of variation
in metabolic rate.
• 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
– Screen for therapeutic activity
– Further evaluate toxicity
• Trial design-
– case series
• Typical Gehan Design
– That is, want to check if drug likely to work in at least 20%
1. Enter 14 patients
2. If 0/14 responses, stop and
declare true drug response 20%
3. If 1+/14 responses, add 15-40
4. Estimate response rate & C.I.
• Phase III -the "pre-marketing phase"
• This phase is designed to assess the effectiveness of the new intervention
and thereby, its value in clinical practice
• The percentage of Phase II trials that proceed to Phase III, as of 2008, is
• 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.
• Comparative Studies
• Experimental Group vs. Control Group
• Establishing a Control-placebo or active standard therapy
• Randomized Control Trial (RCT) is the gold standard
– Eliminates several sources of bias
Phase III Design
• Placebo -controlled trial- the control treatment is a placebo.
• A placebo (inert substance) is preferable to ―no treatment‖ without a pill for
• The placebo effect -the act of taking a pill or receiving a treatment may
exert some benefit apart from the active ingredient.
• Second, use of a placebo pill should minimize the risk for unblinding
participants and data collectors if the placebo is identical or very similar in
appearance, taste, and smell to pills with active therapy
On international realm, 1999 ―Declaration of Helsinki‖ revised to address use
• Placebos not ethical in virtually all studies that involve diseases with
• Remain ethical in trials where no proven tx.
DRUG TRAIL IN CVS
Issues in Clinical Trials: Use of Placebo Trials
• Active controlled trial-
• Given the burgeoning supply of new treatments in the cardiovascular
armamentarium, more and more trials compare the test therapy to a
• A new treatment used in a series
• Outcome compared with
previous series of comparable
• Non-randomized, non-concurrent
• Rapid, inexpensive, good for
initial testing of new treatments
• Two sources of historical control
• Literature Subject to
• Data base
• Tend to exaggerate the value of
a new treatment
Historical Control Study
DRUG TRAIL IN CVS
• Not randomized
• Patients compared, treated by
different strategies, same period
– Eliminate time trend
– Data of comparable quality
– Selection Bias
– Treatment groups not comparable
DRUG TRAIL IN CVS
• Patients assigned at random to either treatment(s) or control
• Considered to be ―Gold Standard‖
• Stratified Randomization
• patients are formed into risk groups (strata) based on 1 or more
prognostic factors, and a separate randomization is conducted for each
• When the treatment assignment groups are then summed over the
various strata, the end result is a forced balance of these overall
treatment groups according to the factors used to form the strata.
Randomized Control Clinical Trial
1. Generalizable Results?
– Subjects may not represent general patient
population – volunteer effect
– Twice as many new patients
3. Acceptability of Randomization Process
– Some physicians will refuse
– Some patients will refuse
4. Administrative Complexity
5. Interefere doctor – patient relationship.
Disadvantages of Randomized
Control Clinical Trial
• Cross Over
Commonly Used Phase III Designs
• The most common type of design
is a parallel-arm trial with two or
• In such a design, participants
remain assigned to their
randomized group until the end of
follow-up. Parallel-arm trials are
relatively easy to understand,
especially the basic two-group
• An alternative is the crossover
design, in which individuals are
randomly assigned to a sequence
(comparison treatment followed
by new treatment, or vice versa).
Crossover trials can be performed
when the outcome is reversible,
such as BP
PARALLEL-ARM CROSSOVER DESIGN
• Factorial Design
• In a factorial design, multiple
treatments can be compared with
control within a single trial through
independent randomizations .
• More practical for CVD patients.
• Each intervention should be
evaluated individually against control
and the possibility of interaction
between the factors should be
evaluated, because the validity of
comparisons within each factor
depends on the absence of interaction.
• Factorial designs may not be
appropriate if there is an a priori
reason to anticipate interactions (e.g.,
resulting from related mechanisms of
DRUG TRAIL IN CVS
• Regulatory submission
• 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.
• That is provided for review to the appropriate regulatory authorities in
different countries for approval and to market the drug by sponser.
• Phase IIIB studies
• 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 to obtain additional safety data, or to support marketing
claims for the drug.
• Most drugs undergoing Phase III clinical trials can be marketed under FDA
norms with proper recommendations and guidelines through a New Drug
Application (NDA) containing all manufacturing, pre-clinical, and clinical
• In case of any adverse effects being reported anywhere, the drugs need to
be recalled immediately from the market.
• 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 EMA (European Union),
• PHASE 4 CLINICAL TRIALS (Therapeutic use studies).
• Post Marketing Surveillance Trial.
• 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 interactions ).
• The main rationale behind conducting Phase IV trials is
– In prior clinical trials, up to Phase 3, patients are selected and limited in
– Conditions of use in trials differ from those in clinical practice
– Duration of trials is limited
– Information about rare but serious adverse reactions, chronic toxicity,
use in special groups (such as children, the elderly or pregnant women)
or drug interactions is often not available.
Phase I Phase II Phase III F
FDA Phase IV
Years 3.5 1 2 3 2.5 12
20 to 80
100 to 300
5 enter trials 1
The entire process of a drug from lab to this point may take approximately 12 to 18
years (but not always), often costing over $1bn.
For Every 10,000 – 30,000 drug molecules screened, only 1 reaches to the Market.
• Phase V
• Phase V is a growing term used in the literature of translational research to
refer to comparative effectiveness research and community-based research;
it is used to signify the integration of a new clinical treatment into
widespread public health practice.
• CDM (Clinical Data Management) is an integral part of the clinical trial
process, which ensures the validity, quality, and integrity of data collected
from trial subjects to a database system for statistical analysis & draw
conclusions regarding the effectiveness, safety, and clinical benefit / risk of
the drug product under investigation.
• The CDM process includes:
– Case Report Form (CRF) development
– Database development and validation
– Data entry, query, and correction
– Data quality assurance
– Data lock, archive, and transfer.
Clinical Data Management)
• Events in a clinical trial may be measured on a nominal (dichotomous),
categorical, or interval (continuous) scale.
• Clinical trials reports should use descriptive statistics, graphic displays, and
estimates of the precision of the observations appropriate for the scale of
measurement being used in the trial.
• Always have a clear plan on how to collect data-- design and pilot
questionnaires, case report forms.
DATA COLLECTION / MANAGEMENT
Statistical significance and power
• Statistical significance is based on the Type I or Alpha
– the probability of rejecting the null hypothesis when it was true
(saying there was a relationship when there isn‘t one)
– usually we accept being wrong <5% of the time, or alpha=0.05
– Setting alpha depends on how important it is that we not make a
mistake in our conclusion.
• The Type II or Beta error is the probability of accepting the
null when it was false
– saying there is no relationship when there is one
– power is 1-B, and 80% or 90% (beta error of 10% or 20%) is
• Measures and Detection of Treatment Effect
• A common assessment in a cardiovascular trial is comparison of the
proportion of patients experiencing a dichotomous event (e.g., dead versus
• When the outcome is an undesirable response and the data are arranged as
investigational group compared with control group, a relative risk (RR) or
odds ratio (OR) of less than 1 indicates benefit of the investigational
• Interpretation of the treatment effect should take into account the absolute
risk of the outcomes.
• The absolute risk difference (ARD) is the difference in events in the
treatment group and the control group, and is particularly useful when
expressed as the number of patients that must be treated (N = 1/ARD), or
number needed to treat (NNT), to observe the beneficial effect in one
• The p-value, or alpha error most commonly indicates the precision of the
result, with a low p-value corresponding to a precise result.
• A t-statistic, Chi-square value gives the relative magnitude of a relation.
• The higher the magnitude of the above statistics, the more precise or stronger
is the relationship between the explanatory variable (s) and the outcome of
Measures of Precision of Effect
• The estimate of where the true value of a result lies is
expressed within 95% confidence intervals, which will contain
the true relative risk or odds ratio 95% of the time .
Precision of Effect: The Confidence Interval
Detection of treatment effects in clinical trials. Factors related to trial design (top) and to
the patient and drug being investigated (bottom) are shown. The interplay of these factors
influences the ability to detect a treatment effect in a clinical trial.
Fallacies in Presenting Results: Statistically vs. Clinically
• Having a large sample size can virtually assure statistically significant results
even if the correlation, odds ratio, or relative risk are low
• Conversely, an insufficient sample size can hide (not significant) clinically
important differences (higher beta error or concluding no difference when
there is one)
• Statistical significance directly related to sample size and magnitude of
difference, and indirectly related to variance in measure
• Clinical versus Statistical Significance
• Clinical significance pertains to the magnitude of benefit that would be
sufficient to change practice or public health policy
• Statistical significance-pertains to the probability that the observed result
occurred bychance alone; it commonly is expressed as a P value.
Statisticalsignificance depends on both the magnitude of benefit and the
• CONSORT (Consolidated Standards Of Reporting Trials)
• Minimum set of recommendations for reporting randomized trials.
• It offers a standard way for authors to prepare reports of trial findings,
facilitating their complete and transparent reporting, reducing the influence
of bias on their results, and aiding their critical appraisal and interpretation.
• The most recent version of the Statement—the CONSORT 2010
Statement—consists of a 25-item checklist and a participant flow diagram,
along with some brief descriptive text.
• The checklist items focus on reporting how the trial was designed,
analyzed, and interpreted.
CONSORT - Consolidated Standards of Reporting Trials
• An official journal for the Society for Clinical Trials
• The first issue was published in the May of 1980.
• Aim and scope:
– Basic Design
– Operating features
• Current editor (1999-) James D. Neaton
Controlled Clinical Trial A Journal
If We areTaking Part in Research
Questions to Ask
• What is study about?
• What are the goals?
• Study sponsor?
• Participant input into
• Inclusion criteria?
• Benefits & risks
• Is there an incentive?
• How protected from harm?
• What is required: # study
visit & what occurs?
• What happens after study is
• How results will be
DRUG TRAIL IN CVS
Overview of Clinical Trial
Well-designed and rigorously conducted trials provide extremely
useful information that can inform or guide, clinical