Informatics Question of the Week: Clinical Research

Clinical research

• Preclinical research includes in vitro (performed with cells or biological molecules studied outside their normal biological context) and in vivo (clinical studies on animals, but not humans) studies, in the process of which various dosages are studied in order to get preliminary data about the studied drug’s pharmaceutical properties, toxicity, pharmacokinetics and the metabolism.
• Phase 0. This phase studies the pharmacodynamics as well as pharmacokinetics of the studied drug. The dosage of the drug cannot exceed half of the therapeutic dosage. The most common study size during this phase is around ten participants.  This phase has the status of high responsibility – first-in-human trials.
• Phase I. Phase I studies usually involve from 20 to 100 healthy volunteers. It sometimes happens that the high toxicity of the drug (for example, drugs to treat oncological diseases and HIV/AIDS) makes it unethical to test such a drug on healthy volunteers, in which case those with the studied disease will make up the study's participants.
• Phase II. Having studied the pharmacodynamics and pharmacokinetics as well as the safety of the tested drug during the Phase I, the company starts the Phase II studies involving a larger amount of subjects (from 100 to 500 humans).
• Phase III is randomized controlled multi-central studies involving larger amount of subjects (from 300 to over 3,000 depending on the disease). Phase III studies are planned in such a way to confirm the safety and effectiveness of the drug that were determined during the Phase II. The Phase III studies: the effect’s dependence on the dosage of the drug, the drug’s effectiveness for diseases of various severity as well as the drug’s ability to be combined with other drugs.
• Phase IV includes studies of the drug after it has been registered with the data confirmed so far. Phase IV studies are studies that were not required to register the drug, but are required to optimize its further use.
• Phase V. This phase analyses the collected data and integrates the data into medical practice.

Question

1. The amount of money paid to subjects;
2. The effectiveness of the studied drug;
3. Phase 0 dosage is two times lower than Phase I dosage;
4. Phase 0 and Phase I differ only in the amount of subjects involved.

Answer and explanation

References and Recommended Reading

Designing Clinical Research

By Stephen B. Hulley, Steven R. Cummings, Warren S. Browner, Deborah G. Grady, Thomas B. Newman

What Makes Clinical Research Ethical?