The biological sciences are involved in virtually
every stage of the development of a new drug. Biological science
specialists represent a wide range of skills, and work together
on the development of new medicines. Here are few examples:
Molecular biologists search for therapeutic targets (such as
proteins, enzymes, cell receptors, genes), upon which a new drug
can act.
They are generally in search of new biological markers (biomarkers)
which will allow for earlier and more precise disease detection
and better understanding of the disease. Using robotic technology,
they test thousands of potentially interesting molecules (HTS:
high throughput screening) using in vitro cell cultures, cellular
fragments or target proteins/enzymes, in order to see which
have the desired therapeutic effects. Molecular biologists can
also
use transgenic animals (for example, “knock-out” animals,
lacking one specific gene) to evaluate the effects associated
with the inhibition of protein synthesis normally induced by
this gene.
Using in vitro animal and human cell cultures, biochemists devise
methods to test target molecules for desired metabolic properties
and therapeutic efficacy. Two key research avenues involve the
enzymes that metabolize these molecules (drugs) and proteins
that act as receptors. Furthermore, biochemists must detect molecules
that are inadequately metabolized, thereby presenting toxic risks.
They also test regularly to verify the stability of molecules
(new
drugs) as a function of time and their method of storage.
Pharmacologists use
animal models of human diseases in order to understand in what
conditions the pathology appears (ethiology).They
study the relationship between drug concentration and a specific
physiological result; they evaluate lead molecules for their
therapeutic activity and their relative toxicity; pharmacologists
determine
the distribution of drugs throughout organs and tissues; they
determine the dosages of potential new drugs safe for human use.
Veterinary surgeons take care of laboratory animals, respecting
national guidelines. They also collaborate on toxicity analyses
of new compounds on laboratory animals.
The bioinformaticians cover
a vast field which includes the storage, analysis, treatment,
organization, comparison
and diffusion of experimental results relative to the biological
sciences (physiology, biochemistry, molecular biology and, to
a great extent, genetics, genomics and proteomics). Bioinformatics plays
a crucial role in identifying therapeutic targets.
Chemists dedicated
to drug discovery and development combine knowledge in organic
chemistry, combinatorical chemistry
(an approach to chemical synthesis that creates large numbers
of organic compounds by putting chemical “building blocks” together
in every possible combination) and analytical chemistry.
They collaborate actively with researchers in biological
sciences.
Medicinal chemistry
specialists synthesize
new compounds or use libraries of already existing molecules.
Lead molecules are optimized by chemists
until tests done by biologists show that they have finally
synthesized
an optimal molecule with significant therapeutic potential.
Then,
process chemistry specialists scale
up the process for chemical synthesis of, initially, the
kilograms of the
bulk drug needed
for preclinical research on animals and clinical research
on humans and, finally, the thousands of kilograms required for
factory scale
production.
The task of clinical research is to demonstrate
that lead molecules show the essential characteristics needed
for safe administration to humans (healthy volunteers first,
then patients
with the target disease), thereby becoming effective drugs.
Clinical trials determine the drug’s efficacy, measure
the tolerance to the drug and adjust the dosage as a function
of the patient’s
age and sex . The specialists associated with this activity
are numerous. Clinicians (physicians)
and pharmacologists prepare
clinical trial program procedures, in accordance with project
objectives
and national guidelines set by bodies such as the U.S. Food
and Drug Administration (FDA-USA) or Health Canada. Ethics
committees examine
all projects to ensure that human rights are respected, that
participants are fully informed of all aspects of the trial,
and that all procedures are done under complete confidentiality.
Doctors monitor
subjects’ health
during clinical trial programs. Nurses administer
medication, collect samples (blood, urine, tissues, etc.)
and complete forms with human subjects, all in accordance
with established procedures. Biological
and chemical science specialists analyze
samples and results. Throughout the process, research
teams are required to
examine results from the perspective of their discipline,
yielding a better understanding of the
drug’s actions and
its impact on individuals. To do this, pharmaceuticals industries
often associate with university research teams and hire research
companies under contract. Biostatisticians carefully
analyze results and present them graphically.
