DEFINITION OF NEW DRUG
STEPS IN THE DRUG DEVELOPMENT
TIMELINE OF PATENT
Development of new drug is very difficult, time consuming &
very expensive process.
During last 50 years, hundreds of new drugs have been
introduced, & many older drugs have been withdrawn.
< 1% of compounds that go into test eventually become licensed
To bring a new drug to market requires a good understanding of
drug development process & integral role preclinical testing plays
In the past most drugs have been discovered either by
identifying the active ingredient from traditional remedies or
by serendipitous discovery.
But now we know diseases are controlled at molecular and
Also shape of an molecule at atomic level is well understood.
Information of Human Genome.
Since the period of patent protection for a new drug(normally
20 years) starts when the compound is registered with the
5000– 10,000 compounds yield 1 new drug to market.
New drug: definition under Schedule Y
New substance, which except during local clinical trials, has
not been used ever before in the country.
Drug already approved for certain claims but which is now
proposed to be marketed with modified or new claims
(indications, dosage, dosage form, route of administration).
FDC of two or more drugs, proposed to be combined for first
time in a fixed ratio.
Authority to grant permission for New Drug to test &
market new drug in India rests with “Drugs Controller
General of India (DCGI)”, and is given as per Drugs &
Schedule Y of Drugs & Cosmetic Rules, regarding
investigation of new drug (NDA) gives details of
preclinical (animal) data required as also issues
guidelines on clinical trials which are required to be
carried out for import & /or manufacture of new drug
US :- FDA (Food and Drug Administration)
Europe :- EMEA (European Medicines
UK :- MHRA (Medicines and Healthcare
products Regulatory Agency)
Japan :- MHLW(Ministry of Health ,Labour and
COMMON WAYS OF DEVELOPING NEW
DRUGSRandom screening:- It is a sort of blind hitting procedure where
new chemical entities (natural or synthetic) are subjected to series of
pharmacological screening procedures to explore different types of
From natural products. e.g. Plants and animals
Studying disease process.
Using computers to design new drugs.
STEPS IN NEW DRUG
A. Idea or Basic Research
B. New drug discovery
D. Preclinical studies
E. Formulation development
F. IND application
G. Clinical studies
H. Official license / Regulations/Marketing
Start by studying normal & abnormal body functions.
Investigation of each component of the disease (pathophysiology).
Look up information obtained in previous research and publication.
Find out at which stage we can stop disease progression or
development (OUR TARGET!).
Search for targeted drug.
Isolate the index compound.
Perform animal testing to obtain safety data.
Approval to test in humans.
NEW DRUG DISCOVERY
To understand the disease.
Choose a molecule to target with a drug.
Test the target and confirm its role in the disease.
Find a promising molecule (a “lead compound”) that could become a drug.
What is/are the
What is the cause?
Which is the target
What is/are Biochemical
TARGET IDENTIFICATION &
VALIDATIONOften begins with target identification - choosing a biochemical mechanism
involved in a disease condition.
Drugs usually act on either cellular or genetic chemicals within our body, known
as targets believed to be associated with the disease.
Drug candidates are tested for their interaction with drug target.
Up to 5000-10000 molecules for each potential drug candidate are subject to
rigorous screening process.
Once scientists confirm interaction with drug target, they typically validate that
target by checking activity against the disease condition for which the drug is
Lead compound or substance is one that is believed to have potential to
treat disease. Laboratory scientists compare known substances with new
compounds to determine their likelihood of success.
There are a few ways to find a lead compound:
Nature: Until recently, scientists usually turned to nature to find
interesting compounds for fighting disease. Bacteria found in soil and
moldy plants both led to important new treatments.
De novo: to advances in chemistry, scientists can also create molecules
from scratch. They can use sophisticated computer modeling to predict
what type of molecule may work.
High-throughput Screening: This process is the most common way that
leads are usually found. Advances in robotics and computational power
allow researchers to test hundreds of thousands of compounds against
the target to identify any that might be promising.
Biotechnology: Scientists can also genetically engineer living systems to
produce disease-fighting biological molecules.
Leads are sometimes developed as collections, or libraries, of individual
molecules that possess properties needed in new drug. Testing is then
done on each of these molecules to confirm its effect on drug target.
(ALTER THE STRUCTURE OF LEAD CANDIDATES TO IMPROVE PROPERTIES)
Lead compounds that survive the initial screening are then “optimized,” or
altered to make them more effective and safer.
By changing the structure of a compound, scientists can give it different
For example, they can make it less likely to interact with other chemical
pathways in the body, thus reducing the potential for side effects.
Hundreds of different variations or “analogues” of the initial leads are
Teams of biologists and chemists work together closely:
The biologists test the effects of analogues on biological systems.
chemists take this information to make additional alterations that are
then retested by the biologists.
The resulting compound is the candidate drug.
Even at this early stage researchers begin to think about:
how the drug will be made,
considering formulation (the recipe for making a drug, including
inactive ingredients used to hold it together and allow it to dissolve at
the right time),
delivery mechanism (the way the drug is taken – by mouth, injection,
LEAD OPTIMIZATION AT MOLECULAR
New techniques have revolutionized the ability of researchers to optimize
potential drug molecules.
Technologies such as magnetic resonance imaging and X-ray
crystallography, along with powerful computer modeling capabilities,
chemists can actually “see” the target in 3D and design potential drugs to
more powerfully bind to the parts of the target where they can be most
In addition, new chemistry techniques help scientists to synthesize the
new compounds quickly.
NEWER TECHNOLOGIES THAT ARE PIVOTAL TO
THE DRUG DISCOVERY AND DEVELOPMENT
1. Medical genetics:
Genetic linkage studies are used to shift through the human genome to link genes with
particular diseases, while genetic association studies are used to look for known gene
sequence in unselected individuals to determine whether they are more common in one
disease than another.
2. Combinatorial biosynthesis:
It is technique for modelling and building libraries of chemical compounds for
considerations as a drug candidates.
3. Robotic high – throughput screening:
Using miniaturization and fully automated robotic technology, compounds generated
from combinational chemistry, are tested in primary activity screens, identifying lead
compounds for further biological testing and chemical optimization.
4. Bioinformatics :
It is information system developed for analysis of biological,
particularly genomic data
It is used for gene identification and mapping, comparing
sequence data in search of similarities, linking genes with
their associated proteins and biological functions.
Ultimately it is used to identify and validate new targets and
to model disease process.
In the past ,screening of these many
compounds could take up to two
Using robotic high-throughput
screening, this now takes only a few
CHARACTERISTICS OF IDEAL DRUG
Good oral Bioavailability
Low or no interaction with CYP450
Less or minimal adverse effects
Good therapeutic index
NCEs are subject to battery of screening tests designed to
determine different types of biological activity.
Such tests include studies on animal behavior, isolated
tissues, intact animals, animal models of the disease.
1 in every 4000-5000 NCEs screened is marketed.
PHARMACOLOGICAL SCREENING OF CANDIDATE
Pharmacological observations are made, depending on
expected pharmacological properties. e.g. fall in BP, fall in
blood glucose, etc.
At the cellular level, it is possible to understand the mechanism
of action of a drug, whether is acts as:
Receptor agonist / antagonist; if so, its affinity and selectivity.
Inhibitor of key enzyme, etc.
Through this process one can rapidly identify active
compounds, antibodies or genes which modulate a particular
The results of these experiments provide starting points for
Lab and animal testing to determine if the drug is safe enough for
human testing .
In order to gain approval for general medical use, the quality, safety and
efficacy of any product must be demonstrated.
Regulatory authority approval to commence clinical trials is based
largely upon preclinical pharmacological and toxicological assessment of
the potential new drug in animals.
Such preclinical studies can take up to 3 years to complete.
Scientists carry out in vitro and in vivo tests.
The U.S. Food and Drug Administration (FDA) requires extremely thorough
testing before the candidate drug can be studied in humans.
During this stage researchers also must work out how to make large
enough quantities of the drug for clinical trials. Techniques for making a
drug in the lab on a small scale do not translate easily to larger production.
This is the first scale up. The drug will need to be scaled up even more if
it is approved for use in the general patient population.
At pre-clinical stage ,the regulatory bodies will
generally ask, at a minimum that sponsors(s):
Develop a pharmacological profile of drug.
Determine the acute toxicity of the drugs in at least two
species of animals.
Conduct a short-term toxicity studies ranging from 2weeks to
3 months, depending on the proposed duration of use of the
substance in the clinical studies.
Thus pre-clinical testing Involves:
1. Pharmacology testing.
2. Toxicology testing.
3. Animal pharmacokinetics testing.
THE RANGE OF MAJOR TESTS UNDERTAKEN ON A
POTENTIAL NEW DRUG DURING
Bioequivalence and bioavailability
Reproductive toxicity and teratogenicity
“What does the body do to the drug ?”
Relates to the fate of a drug in the body, particularly its ADME, i.e. its
absorption into the body, its distribution within the body, its metabolism by
the body, and its excretion from the body.
Generally, ADME studies are undertaken in two species, usually rats and
Repeated at various different dosage levels. (Males & females).
If initial clinical trials reveal differences in human versus animal model
“What does the drug do to the body ?”
Studies deal more specifically with how the drug brings about
its characteristic effects. Emphasis in such studies is often
Relationship between drug concentration and effect.
Toxicology studies will be carried out both in vitro and on animal species.
Toxicology and safety testing determine the potential risk a compound pose to
man and the environment.
Dosage levels are explored initially at the stage of animal testing in efficacy
and safety models.
Most substances are toxic if given at high enough doses: aims of early drug
development are to characterize the toxicity of a compound and to find the
balance between desired activity and tolerable toxicity.
Toxicity studies are done to calculate:
Maximum tolerated dose
Gross Effects, Clinical Chemistries
Gross pathology to Indicate Target
Satisfactory Therapeutic Ratio vis-à-vis
Animal Efficacy studies
Toxicology studies in preclinical
stage are conducted to
Select or reject lead
General indication of
Dose selection and
guidance to clinician
TYPES OF TOXICOLOGICAL
INVESTIGATIONSAcute toxicity 2 weeks studies in 3-4 species to
determine maximum tolerated dose.
Sub-acute toxicity 6 months studies in 2 species
Chronic toxicity Up to 12 months studies in rats
and non-rodent to determine if
adverse effects occur with
repeated daily dosing.
o At least 18 months in mice
o 2 years in rat
Earlier studies demanded calculation of an LD50 value (i.e. the quantity of the drug required to
cause death of 50 per cent of the test animals). Such studies required large quantities of
animals, were expensive, and attracted much attention from animal welfare groups.
Nowadays, in most world regions, calculation of the approximate lethal dose is sufficient.
REPRODUCTIVE TOXICITY AND
TERATOGENICITYAll reproductive at three different dosage levels (ranging from non-
toxic to slightly toxic) to different groups of the chosen target
species (usually rodents).
Fertility studies aim to assess the nature of any effect of the
substance on male or female reproductive function.
The drug is administered to males for at least 60 days (one full
Females are dosed for at least 14 days before they are mated.
These reproductive toxicity studies complement teratogenicity
studies, which aim to assess whether the drug promotes any
developmental abnormalities in the foetus. (usually rats and rabbits)
MUTAGENICITY, CARCINOGENICITY AND OTHER
Mutagenicity tests aim to determine whether the proposed drug is capable of inducing
DNA damage, either by inducing alterations in chromosomal structure or by promoting
changes in nucleotide base sequence.
Mutagenicity tests are usually carried out in vitro and in vivo 18-24 month, often using
both prokaryotic and eukaryotic organisms.
Longer-term carcinogenicity tests are undertaken, particularly if
(a) the product’s likely therapeutic indication will necessitate its administration over prolonged
periods few weeks or more .
(b) if there is any reason to suspect that the active ingredient or other constituents could be
For many biopharmaceuticals, immunotoxicity tests (i.e. the product’s ability to induce
Now a days, extensive toxicological studies ensure that drugs causing
serious toxicity do not reach the market, unless of course the agent
concerned has potentially life saving role in treating a diseases.
And where no other more suitable drugs are available.
At present, HIV infection represents such a serious threat to life that is
considered acceptable to use drugs to treat it which rather toxic to human
INVESTIGATIONAL NEW DRUG (IND) APPLICATION AND
After completing pre-clinical testing, the company files an IND with FDA or DCGI in
India to begin to test the drug in human.
File IND with the FDA before clinical testing can begin; ensure safety for clinical trial
volunteers through an Institutional Review Board(IRB).
Before any clinical trial can begin, the researchers must file an Investigational New
Drug (IND) application with the FDA.
The application includes :
The results of preclinical work,
Candidate drug’s chemical
how it is thought to work in the
listing of any side effects ,
method of product manufacture
The IND also provides a detailed clinical trial plan that outlines how, where
and by whom the studies will be performed.
The FDA or DCGI reviews the application to make sure people
participating in the clinical trials will not be exposed to unreasonable risks.
All clinical trials must be reviewed and approved by the Institutional
Review Board (IRB) at the institutions where the trials will take place.
This process includes the development of appropriate informed consent,
which will be required of all clinical trial participants.
Statisticians and others are constantly monitoring the data as it becomes
The FDA or the sponsor company can stop the trial at any time if
In some cases a study may be stopped because the candidate drug is
performing so well that it would be unethical to withhold it from the
patients receiving a placebo or another drug.
Finally, the company sponsoring the research must provide
comprehensive regular reports to the FDA and the IRB on the progress of
The discovery and Lead Optimization of any substance of potential
pharmaceutical application is followed by its patenting.
A method of synthesis and its biological effects, the better the
chances of successfully securing a patent.
Thus, patenting may not take place until preclinical trials and phase
I clinical trials are completed.
Patenting, once successfully completed:
1. it must be proven safe and effective in subsequent clinical trials,
2. be approved for general medical use by the relevant regulatory authorities.
WHAT IS A PATENT AND WHAT IS
A patent may be described as a monopoly granted by a
government to an inventor, such that only the inventor
may exploit the invention/innovation for a fixed period
of time (up to 20 years).
In order to be considered patentable, an
invention/innovation must satisfy several criteria:
sufficiency of disclosure
Before a drug can formulated, we must known about its physio-chemical
properties and behaviour (e.g. its solubility, its crystal structure).
These will dictate, the dosage forms in which medicine will be marketed
and can be used during drug development investigations.
Pre-formulation studies will attempt to characterize the drug by
Spectroscopy, Solubility, melting point, Assay development, Stability,
Microscopy, Powder flow and compression properties, Excipient
Dosage form design
At some stage, a decision needs to be made about the dosage forms for
the delivery of the drug (e.g. tablet, capsule).
Types of dosage form
There are many different dosage forms and they all have their relative
advantages and disadvantages.
(e.g. Tablets and capsule, Injections and Infusion, Pessaries and
suppositories, Solution, Suspension, Elixirs, Ointment, Creams, Paints,
Aerosols, Dry powder inhalations, transdermal patches.)
CLINICAL DEVELOPMENT OF DRUG
A clinical development plan is a comprehensive plan designed to
map out the development of a drug compound from early Phase-1
studies through marketing.
The clinical development plan contains a summary of the pre-
clinical findings and of market research done for the drug.
Phases of clinical research
Clinical research is done in four phases(1,2,3&4),each designed to
address different questions.
Based upon data gathered from pre-clinical testing, the sponsor
has estimation of:
•The drug’s therapeutic effect and dose levels.
PHASE I CLINICAL TRIALS
The main goal of a Phase 1 trial is to discover if the drug is safe in
This is a open study conducted in healthy human volunteers (20-
In special populations (e.g. for anti-cancer drugs).
In phase I studies regulatory bodies (i.e. FDA)can impose a clinical
hold(i.e. prohibit the study from proceeding or stop a trial that has
started) for reasons of safety ,or because of sponsor’s failure to
accurately disclose the risk of study to investigators.
Phase I Trial Address:
How rapidly the drug is absorbed?
Where is the drug distributed in the
Which organ or organ system are
involved in metabolism of drug?
How quickly is the drug eliminated from
FACT: only about
Phase I clinical
PHASE II CLINICAL TRIALS
Therapeutic exploratory trials.
First trial in patients with the
disease to be treated.
50-300 patients are used for
Effectiveness of the drug
Common short term side
effects and risks with I.N.D.
Determine doses and regimens
for phase III trials
PK, PD, safety
Target populations for further
studies in phase III
FACT: only about 35% of experimental drug passes Phase II clinical trial.
Phase II Trial address:
What is the minimum effective dose?
What is the maximum tolerated dose?
Is the drug effective in mild, moderate,
and severe cases of the disease or
Is the drug effective for all expected
SPONSOR/FDA MEETING (END OF
One month prior to the “end of the Phase 2”, the sponsor should
submit the background information and protocols for phase 3
This information should include data supporting the claim of the
new drug product, chemistry data, animal data and proposed
additional animal data, results of Phase 1 and 2 studies, statistical
methods being used, specific protocols for phase 3 studies, as well
as a copy of the proposed labeling for a drug, if available.
This summary provides the review team with information needed to
PHASE III CLINICAL TRIAL
Phase III studies are extended controlled and uncontrolled trials.
They are performed after preliminary evidence suggesting effectiveness of the drug
has been obtained in phase II ,and intended to gather the additional info about
effectiveness and safety.
It may involve several hundred to several thousand (300-3000)patients and last 1-5
Phase III trials involve different patient sub-groups, such as children, the elderly ,and
perhaps those with impairments in liver and kidney.
Once the phase III completed satisfactory, the drug company to apply marketing
Phase III Trial Address:
Adverse reaction in a large
group of patients over a
longer period of exposure?
The ideal dosage regimen?
Should the drug is allowed
to be marketed?
FACT: only about
25% of a
Phase III clinical
ORGANIZATIONAL STRUCTURE FOR A
TYPICAL PHASE III CLINICAL TRIAL
Clinical Study Site Investigators
CLINICAL TRIAL DESIGN
An incredible amount of thought goes into the design of each
To provide the highest level of confidence in the validity of results,
many drug trials are :
Placebo-controlled: Some subjects will receive the new drug candidate and
others will receive a placebo. (In some instances, the drug candidate may be
tested against another treatment rather than a placebo.)
Randomized: Each of the study subjects in the trial is assigned randomly to
Neither the researchers nor the subjects know which treatment is being
delivered until the study is over.
This method of testing provides the best evidence of any direct
relationship between the test compound and its effect on disease
because it minimizes human error.
However, in many instances, alternative trial designs are
chosen based on ethical or other grounds.
In most cases, two groups are considered: control and test.
However, these designs can be adapted to facilitate more
NEW DRUG APPLICATION (NDA) AND
APPROVALOnce all three phases of the clinical trials are complete, the sponsoring company
analyzes all of the data.
If the findings demonstrate that the experimental medicine is both safe and effective,
the company files a New Drug Application (NDA) — which can run 100,000 pages or
more — with the FDA requesting approval to market the drug.
The NDA includes all of the information from the previous years of work, as well as the
proposals for manufacturing and labeling of the new medicine.
FDA experts review all the information included in the NDA to determine if it
demonstrates that the medicine is safe and effective enough to be approved.
Following rigorous review, the FDA can either
1) approve the medicine,
2) send the company an “approvable” letter requesting more information or studies
before approval can be given, or
3) deny approval.
Review of an NDA may include an evaluation by an advisory committee,
an independent panel of FDA-appointed experts who consider data
presented by company representatives and FDA reviewers.
Committees then vote on whether the FDA should approve an
application, and under what conditions.
The FDA is not required to follow the recommendations of the advisory
committees, but often does.
PHASE IV CLINICAL TRIAL(POST MARKETING
Research on a new medicine continues even after approval.
As a much larger number of patients begin to use the drug, companies
must continue to monitor it carefully and submit periodic reports,
including cases of adverse events, to the FDA.
In addition, the FDA sometimes requires a company to conduct
additional studies on an approved drug in “Phase 4” studies.
These trials can be set up to evaluate long-term safety or how the new
medicine affects a specific subgroup of patients.
WORLD HARMONIZATION OF DRUG
The International Conference on harmonization of
technical requirement for registration of pharmaceuticals
for human use .
A collaboration between regulator from US / EU / JAPAN.
Produce guidelines on drug development and clinical trial
that are accepted across countries.
Good starting place for summaries of clinical trial issues.
PHASE ‘0’ MICRODOSING
A new approach to obtain human pharmacokinetic information
before the usual expensive phase I safety program is conducted is
the phase 0 microdosing.
It is hypothesized that microdosing will help to reduce or replace
the extensive animal testing of compounds for kinetics, which may
later be rejected in human studies.
Thus, micro-dose studies use minute quantities of drug and are not
intended to produce any pharmacologic effect, when administered to
humans, and, therefore, may not cause any adverse events also, but
may produce useful pharmacokinetic information and help in further
1/100th of dose anticipated to produce a pharmacological
A small dose of your own medicine…..
Provides sufficiently useful PK information to decide on
confirmatory development (human & animal toxicology)
Helps in early de-selection: Cost saving related to
manufacturing, scaling up & CTs.
ABBREVIATED NEW DRUG APPLICATION
ANDA is submitted to regulatory bodies to obtain the approval to market
a generic drug product.
It contains data which when, provided for the review and once approved,
an applicant may manufacture and market the generic drug product as a
low cost alternative.
Generic drug applications are termed “abbreviated” cause they are
generally not required to include pre-clinical and clinical data to
established safety and effectiveness.
ESSENTIAL CLINICAL TRIAL
INFORMED CONSENT DOCUMENT
CASE RECORD FORM
CURRICULUM VITAE (CV)
LAB REFERENCE RANGE
CERTIFICATES OF ANALYSIS(COA)
SAE REPORTING FORM
CLINICAL STUDY REPORT (CSR)
The drug discovery and development process is a long and complicated
Before any newly discovered drug is placed on the market, it must undergo
Each success is built on many, many prior failures.
Advances in understanding human biology and disease are opening up exciting
new possibilities for breakthrough medicines.
At the same time, researchers face great challenges in understanding and
applying these advances to the treatment of disease. These possibilities will
grow as our scientific knowledge expands and becomes increasingly complex.
Research-based pharmaceutical companies are committed to advancing
science and bringing new medicines to patients.