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REVIEW ON CLINICAL TRIALS

About Authors:
Kambham Venkateswarlu

Final Year Graduate Student
Sri Lakshmi Narasimha College of Pharmacy,
Palluru, Chittoor-517132, Andhra Pradesh, India.
k.v.reddy9441701016@gmail.com

ABSTRACT:
Clinical trials are the set of procedures in medical research and drug development that are conducted to allow safety and efficacy data to be collected for place only interventions. These trials can take place only after satisfactory information has been gathered on the quality of the country where the trial is taking place.

Depending on the type of product and the stage of its development, investigators enrol healthy volunteers and patients into small pilot studies, followed by larger scale studies in patients that often compare the new product with the currently prescribed treatment. As positive safety and efficacy data are gathered, the number of patients is typically increased. Clinical trials can vary in size from a single centre in one country to multicenter trials in multiple countries.


REFERENCE ID: PHARMATUTOR-ART-1641

TYPES OF CLINICAL TRIALS:
The U.S. National Institute of Health (NIH) organises trials into 5 different types:
A.    Prevention trials
B.     Screening trials
C.     Diagnostic trials
D.    Treatment trials
E.     Quality of life trials

A. Prevention trials:
Look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning.

B.Screening trials:
Test the best way to detect certain diseases or healthy conditions.

C.Diagnostic trials:
Conducted to find better tests or procedures for diagnosing a particular disease or condition.

D. Treatment trials:
Test experimental treatments, new combination of drugs, new approaches to surgery or radiation therapy.

E.Quality of life trials:
Exposure way to improve comfort and the quality of life for individuals with a chronic illness.

PHASES:

  • These are 4 phases. The drug development process will normally proceed through all four phase over many years. If the drug successfully passes through phase I, II, III, it will usually be approved by the national regulatory authority for use in the general population. Phase IV are the ‘post-approval’ studies.
  • Before pharmaceutical companies start clinical trials on a drug, they conduct extensive pre-clinical studies.

PRE-CLINICAL STUDIES:
It involves in vitro and in vivo experiments using wide ranging doses of the study drug to obtain preliminary efficacy, toxicity and pharmacokinetic information. Such tests assist pharmaceutical companies to decide whether a drug candidate has scientific merit for further development as an investigational new drug.

PHASE 0: (HUMAN MICRODOSING STUDIES)

  • First in human trials conducted accordance with the FDA 2006 guidance.
  • These trials are designed to speed up the devel;opment of promising drugs by establishing very early on whether the drug or agent behaves in human subjects as was expected from pre-clinical studies.
  • Phase 0 trials includes administration of single sub therapeutic doses of the study drug to a small number of subjects (10-15) to gather preliminary data on the agent’s pharmacodynamics and pharmacokinetics.
  • A phase 0 study gives no data on safety or efficacy.

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PHASE I (HEALTHY MALES):
Normally, a small (20-100) group of healthy volunteers will be selected. This phase includes trials designed to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of a drug. These trials are often conducted in an inpatient clinic, where the subject can be observed by full-time staff. Phase I trials also normally include dose ranging, also called as dose escalation, studies so that the appropriate dose that causes harm in animal testing. Phase I trials most often include healthy volunteers. The reason for conducting the trial is to discover the point at which a compound is too poisonous to administer.

TYPES OF PHASE I TRIALS:
A.    SAD
B.     MAD

A.SAD (Single Ascending Dose):
These studies are those in which small groups of subjects are given a single dose of the drug while they are observed and tested for a period of time. If they do not exhibit any adverse effects and pharmacokinetic parameter roughly in line with predicted safe values, the dose is escalated, and a group subjects is then given a higher dose. This is continued until pre-calculated pharmacokinetic safety levels are reached or intolerable side effects start showing up.

B.MAD (Multiple Ascending Doses):
These studies are conducted to better understand the pharmacokinetics and pharmacodynamics of doses of the drug. In these studies, a group of patients receives multiple low doses of the drug, while samples are collected at various time points and analyzed to acquire information on how the drug processed within the body.

PHASE II (Patients):
These trials performed on the larger groups (100-300) and are designed to assess how well the drug works, as well as to continue phase I safety assessments in a larger group of volunteers and patients. When the development process for a new drug fails, this usually occurs during phase II trials when the drug is discovered not to work as planned or to have toxic effects.

TYPES OF PHASE II STUDIES:
A.    Phase IIA
B.     Phase IIB

A.Phase IIA: How much drug should be given.

B.Phase IIB: How well the drug works at the prescribed dose.

Some trials combine phase I and phase II and test both efficacy and toxicity.

PHASE III (Geriatrics):

  • These studies are randomizede controlled multicenter trials on large patient groups (300-3000 or more depending upon the disease) and are aimed.
  • How effective the drug is, in comparison with current ‘gold standard’ treatment. Because of their size and comparatively long duration, ohase III trials are the most expensive, time consuming and difficult trials to design and run, especially in therapies for chronic medical conditions.
  • While not required in all cases, it is typically expected that there be at least two successful phase III trials, demonstrating a drug’s safety and efficacy, in order to obtain approval from the appropriate regulatory agencies such as FDA (USA), or the EMA (European Union).

PHASE IV (Paediatric):

  • This trial is also known as Post marketing Surveillance Trials.
  • The safety surveillance is designed to detect any rare or long-term adverse effects over a much larger patient population and longer time period than was possible during the phase I-III clinical trials.
  • Harmful effects discovered by phase IV trials.

PHASE V:

  • Phase V is a growing term used in the literature of translational research to refer to comparative effectiveness research and community based research.
  • It is used to signify the integration of a new clinical treatment into widespread public health practice.

CONCLUSION:
We are the pharmacist we have ability to do clinical trials on experience. We should not neglect at any step because it will affect the life of the volunteers. We should not play with their lives. If we neglected the cost is some lives.

REFERENCES:
1.    Avorn J. (2004) Powerful Medicines, P. 129-133.
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3.    The regulatory authority in the USA is the FDA; in Canada, Health Canada; in the European Union, the European Medicines Agency and in Japan, the Ministry of Health, Labour and Welfare.
4.    Clinical trials in oncology, Stephanie Green, Jacqueline Benedetti, John Crwley (2003). CRC Press P.1. ISBN: 1-58488-302-2
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6.    Curtis L.Meinert, Susan Tonascia (1986). Clinical trials: design, conduct and analysis. Oxford University Press, USA. P.3. ISBN: 978-0795035681.
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