Basic Clinical Research Tutorial

What is Clinical Research?
Clinical Research is systematic study of new drugs, devices, biological products and vaccines intended for diagnosis, prevention or treatment of diseases. The aim of the study is to improve healthcare in the society by making safe and effective drugs available at low cost.

The new drug development process involves drug discovery, animal experiments followed by studies conducted on human beings to assess the therapeutic effectiveness and toxicity by way of well designed experiments known as clinical trials. The word clinical refers to human beings. Clinical trials are conducted in three phases with increasing participation of human subjects at each subsequent stage. Clinical trials ensure safety and help to prove therapeutic efficacy of the new drug before the drug is available for prescription. Since drug trials involve human subjects, these are governed by scientific, medical, ethical, and legal guidelines to impart maximum safety and benefits to human subjects participating in the trials.


What are Clinical Trials?
Clinical Trials are studies conducted on human subjects for verifying the clinical, pharmacological and adverse effects of the drug. These are clearly defined and well designed studies to meet the objective of determining safety and efficacy of the new drug. They are generally comparative studies conducted in a randomized double blind fashion. The subjects participating in the study are duly informed about the risks and benefits involved in the study and a written voluntary consent is obtained. A protocol is prepared describing the details of the various steps and procedures to be followed which must be duly approved by an independent Ethics Committee. The data generated is submitted to the regulatory authority with New Drug Application for registration and marketing approval.


Why Clinical Research?
Clinical research helps to bring new drugs into the market for new diseases, or introduce drugs with lesser side effects, drugs having low cost, better compliance, and lower undesirable drug interactions. They may be conducted to study delayed and long term adverse effects of the drugs meant for chronic ailments. All new vaccines, Diagnostic products, medical devices, biological and biotechnology products are considered as new drugs and have to undergo similar testing before marketing.


Why are Clinical Trials important?
Animal data help to predict the biological effects and toxicity of a new drug but cannot be directly extrapolated to humans due to species differences. The only way to know the actual effects of a drug in human beings is through human experiments or trials. Well designed trials conducted based on sound scientific principles and standards (Good Clinical Practice) generate good quality data for interpretation and regulatory approval.


What are phases of Clinical Trials?
These are the stages of drug developments with increasing information on human safety and effectiveness. There are four phases of trials and the results of one phase help to plan the next. Conducting trials in phases helps to minimize risk by exposing limited number of subjects at each stage and generate sufficient data for further studies. Of these phases three are conducted for regulatory approval of the drug or device and the fourth phase is conducted after marketing.

Pre regulatory clinical trials are been divided into 3 Phases:

Phase I: These are also known as Human Pharmacology. This is the most crucial phase since the new drug is given for the first time to a small group of healthy human volunteers under close medical supervision to assess the tolerability and toxicity at selected doses. The pharmacokinetic and pharmacodynamic parameters are studied to establish the safety of the new drug in human being. This study may be done with increasing doses or repeating single doses.

Phase II: These are known as Exploratory Trials. After the drug has been proved safe in phase I, it is tested on few hundred patients to assess the therapeutic effectiveness and safety. Both improvement in disease symptoms and adverse effects are observed and recorded on structured sheets called Case Report Form.

Phase III: These are also known as Confirmatory Trials. The studies are conducted in a larger number of patients and the efficacy and safety of the new drug is compared with a standard drug based on predefined criterion. This phase is conducted at multiple sites and includes few thousand patients who resemble end users. Majority of the time and money spent on clinical development is in this phase.


Disclaimer : The above data is taken from website http://www.bilcareacademy.com/faq.htm