Clinical Trials

According to the World Health Organization (WHO) clinical trials are “…any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes. For the purpose of registration…”

Clinical trials can be conducted on Medication, Devices, or they could just be survey or monitoring trials. Ethical Committees and the Food and Drug Administration supervise these trials.

Phase 1

Phase 1, or “first in human” trials, are new medications yet to to be approved by the FDA for their intended purpose in their stated dosage or studies for new medical devices that need FDA approval.

These studies see the highest probability of adverse effects, for this reason they are the highest paying trials for subjects (clinical trial volunteers).

They are conducted in a small population usually less than a hundred and relatively healthy subjects in most cases.

Many labs are drawn during this phase to evaluate toxicity of any new medications, or dosage levels.

Phase 2

Phase 2 is conducted in hundreds of patients. These patients usually have the desired condition that the medication or device is intended to treat.

This phase is also used to start determining the placebo effect of the medication or device. To measure this subjects are randomized into one, of usually, two groups one being the medication the other a placebo, or sugar pill.

The efficacy of the drug or device is also measured.

Phase 3

Phase 3 is conducted in hundreds to thousands of patients. It usually involves some form of blinding and randomization.

Blinding is when the patient does not know what he/she is receiving; double blind is where the patient and the investigators do not know what the patient is getting.

This phase can last several years, and is used to provide further information to the FDA as to the effectiveness of the device or drug.

Usually drugs and devices that make it to phase 3 get approved by the FDA, after which they are introduced to the market.

Phase 4

Phase 4 is a post market phase. This is usually for medications or devices that have already been approved by the FDA and are in the market.

The main goal of this phase is to compare the drug to its competitors, monitor long term effectiveness, and determining the cost effectiveness of the device or drug.

Results form these studies can have significant impact on certain drugs. If increased toxicity is shown in a long-term study drug can be discontinued.

Placebo Effect

Post Market Phase