Introduction to Clinical Trials

After an epidemic of coronavirus, we usually hear in the news that biotech companies, clinical researchers, and other health professionals are making vaccines or drugs to combat coronavirus. Some of them have been approved and now are in use. Some of them are still in different phases of trials. Have you ever think what are these trials? So with this article, I’ll provide you a brief introduction about what are clinical trials, what are their different phases, how these trials are conducted, who conduct them, what happens after the completion of trials, and many more.

What are clinical trials?

These are the research studies that are organized in a group of people ranging from several hundred to thousands in such a way to study, acknowledge and test new medical treatment, pharmaceutical preparations like vaccines, medicines, medical devices, etc. These trials can also be used to enhance already available such things.

Basic scheme of a research:

Discovery→ Preclinical Research → Clinical Research → FDA Approval

On average whole research, work timeline is of 12 years. At first, small level research is done to understand normal human biology and disease in laboratories. Then, already available treatments are tested so as to get an idea in which direction a researcher has to do new research.

  • Pre-clinical research includes compound selection and which is generally done in three tiers. In first tier tests, study of binding of compounds to its receptor, its solubility, its LLE , its binding to hERG etc. The compounds which passed 1st tier tests are then tested for oral efficacy, Ames mutagenicity etc. which comes under second tier tests. And at last only one or two compounds are processed to third tier tests, this compound can be a golden bullet, which generally involves dose escalation PK studies, its in vivo(in animals) testing to study its safety and side effects . Preclinical research can usually take 5-6 years.
  • Once the pre-clinical research is over, compound selected for drug development or the new developed treatment is approved to pass through different phases of clinical trials which comes under clinical research.
  • Once a treatment or a drug appears to pass through all phases of clinical trials, it is approved by FDA and then it is accepted in market.
  • It can take 10-15 years to pass a drug to pass clinical trails and get market approval.

Different phases of clinical trials:

PhaseNATURENo. of
0Pilot studyVery small number of people,
usually fewer than 15
To test how human body respond to small dose of drug.
15-100 To study the safety, remedial dose and side effects.
IIproof of concept100sTo study fruitfulness and safety of treatment.
IIIStage of regulation100-1000sTo confirm clinical benefit and to compare it with another methods.
Large no. of populationTo study long term effects in general population.

Controlled trails:

In this, there are two groups one of them receives new treatment and other receives the comparison treatment which is called as control group. The group receiving new treatment is of patients and unhealthy people and control group is of healthy people.

Use of placebos in controlled trials:

A placebo is a treatment that looks identical to to treatment under study which are used as inactive control to study side effects, safety measure of a treatment on a human body.

Blinded and double blinded:

A trial is blinded when participants are unaware of the fact that they are under controlled trials until studies are complete. A trial is double blinded when investigators are also unware of which participant is under treatment or which is under control. Blinding clinches that results are not biased.

The safety of a participant is first priority.

If at any phase of clinical trials, there are serious safety concerns or the study feels like waste of time then a clinical trial may get terminated.

Who coordinates these trials?

Clinical trials are usually conducted by equal contribution of health professionals from different fields like doctors, nurses, researchers, allied health practitioners, pharmacists , engineers.

What after trial ?

 Once the trial has been closed, all study information and data are collected, compiled, analysed and interpreted. Then a final study report is produced. The study may also be published in a scientific journal. These should be made available to the participants.

After successful trial, the treatment/drug will receive approval and will be available for everyone in markets and stay under post-market monitoring to investigate it more.

References :


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