The on-going pandemic situation gave humanity a hard lesson- life is uncertain. Before the pandemic, we never seriously thought about this type of disease which could lead to such a global health crisis. Now, Covid-19 is a reality and it taught us that as the virus changed itself we must constantly change ourselves and be prepared for sudden battles. Humanity has a long history of fighting against deadly diseases like plague, malaria, polio, cholera, etc. and in all those battles our greatest weapons are drugs. In this article, we will see how biochemistry is an integral part of a drug discovery process.

Biochemistry is the amalgamation of chemistry and biological sciences. It brings together all of the sciences to study the chemical and physical processes that occur in living organisms. It truly is the science of life. Students of biochemistry learn various classical as well as modern subjects like stem cell biology, immunology, bioinformatics, genetic engineering, and many more. These subjects give them ample knowledge about the basic processes of life and that gives them the scope to explore properly a particular phenomenon in a living system. The mixture of chemistry and biology is a tremendous weapon for students for understanding the complex design of a disease-causing bacteria or virus. Applying these knowledge life-saving drugs can be developed by biochemistry professionals.

A drug is a chemical substance that, when administered to a living organism produces a biological effect. Drugs are also called medicine as it is used for treatment, cure, prevent disease, and promote good health. Drugs can be taken via different modes like inhalation, injection, ingestion, absorption via a patch on the skin, suppository, or dissolution under the tongue. So, recently discovered vaccines against Covid-19 are also part of modern-day drugs.

There are several phases of drug discovery and its commercialization; 1) Basic research for lead development 2) Preclinical studies 3) Clinical studies (different phases) 4) Review by regulatory authorities and approval 5) Pre and post marketing monitoring. In all these phases major roles are played by biochemistry people.

The first step of basic research consists of lead molecule discovery and its target identification which is totally done by biomedical scientists. During lead discovery, an intensive search ensues to find a drug-like small molecule or biological therapeutic, typically termed a development candidate, that will progress into preclinical, and if successful, into clinical development and ultimately be a marketed medicine. Generally, drugs are very specific in nature, i.e., they work in a specific manner on a specific type of cell or exo or endotoxins. So, first, to discover the lead, one has to find the type of cell or chemical substances on which the drug is going to affect, what’s the nature of the target.

The next step is the preclinical trial, which is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing, and drug safety data are collected, typically in laboratory animals. This step requires multiple types of studies/tests like screening, tests on isolated organs and bacterial cultures, tests on animal models, general observational tests, confirmatory tests and analogous activities, mechanism of action, systemic pharmacology, quantitative tests etc. that are all done by Biochemistry people. The main purpose of preclinical studies is to accurately model the desired biological effect of a drug in animals [non-human primates] in order to predict treatment outcomes in patients (efficacy), and to identify and characterize all toxicities associated with a drug in order to predict adverse events in people (safety) for informed—preclinical testing analyses the bioactivity, safety, and efficacy of the formulated drug product.

After a proposed drug has gone through premedical trials, the next step is clinical trials. The main difference is while preclinical research answers basic questions about a drug’s safety, it is not a substitute for studies of ways the drug will interact with the human body. The biomedical persons design clinical trials, develop a study plan or protocol and follow them to answer specific research questions related to medical products. Before the trial begins, they decide who qualifies to participate (selection criteria), how many people will be part of the study, how long the study will last, whether there will be a control group and other ways to limit research bias, how the drug will be given to patients and at what dosage, what assessments will be conducted, when, and what data will be collected, how the data will be reviewed and analysed. Clinical trials follow a typical series of early, small-scale, Phase 1 studies [20-100 healthy/diseased volunteers], Phase 3 studies [Several hundred people with the disease], Phase 3 studies [300-3000 volunteers with the disease], and lastly, late-stage, large scale Phase 4 studies [Several thousand volunteers with the disease].

The next step is, review by regulatory authorities and approval of the drug. Drug approval processes are designed to allow safe and effective drugs to be marketed. Drug regulatory agencies in various countries attempt to rely on premarketing scientific studies of the effects of drugs in animals and humans in order to determine if new drugs have a favourable risk-to-benefit ratio. The manufacturer must provide the concerned authority review of all the test and study reports with detailed information about the proposed drug including usage of the drug to be effective, all the possible risks, and how to use it. Physicians and scientists of the concerned authority then review the drug research and the labelling information on how to use the drug. If the findings show the drug’s benefits outweigh its known risks — and that the drug can be manufactured in a way that ensures a quality product.

After the drug gets all the certification, the last step is Post-marketing monitoring. Post marketing drug surveillance refers to the monitoring of drugs once they reach the market after clinical trials. It evaluates drugs taken by individuals under a wide range of circumstances over an extended period of time. Such surveillance is much more likely to detect previously unrecognized positive or negative effects that may be associated with a drug. The majority of post-marketing surveillance concern adverse drug reactions (ADRs) monitoring and evaluation. Therefore, biochemistry people always get an edge in these type of drug developmental industry.