Clinical Trials

• According to the FDA document titled ‘FDA and Clinical Drug Trials: A Short History’, the purpose of a controlled clinical trial is to separate the relative handful of discoveries which prove to be true advances in therapy from the numerous false leads and unverifiable clinical impressions.
• It is also to note that the purpose of a controlled clinical trial is not the "discovery" of a new drug or therapy.
• Clinical trials are designed to answer specific research questions related to a medical product following a specific study plan, called a protocol.
• According to the FDA guidelines, clinical trials follow a typical series from early, small-scale, Phase 1 studies to late-stage, large scale, Phase 3 studies.
• FDA requires these three phases of clinical trial to determine if the drug can be approved for use.
• The Phase 1 trial is used to conduct an experimental treatment on a small group of often healthy people (20 to 80) to judge the safety and side effects of the drug and to find the correct dosage for the drug.
• The Phase 2 trial is conducted on a larger bunch of 100 to 300 people. The purpose of this phase is to gather preliminary data on whether the drug works in people who have a certain disease or condition. It is to note that this phase can continue for several years.
• Finally, a Phase 3 trial is conducted on a large group of people ranging from several hundred to about 3,000.
• The purpose of this phase is to gather more information about the safety and effectiveness of the drug.
• After Phase 3, if the FDA agrees that the trial results are positive, it will approve the experimental drug or device.

Diagnostic Trial

• Clinical trials can be classified according to their objectives and also the way they are organized.
•  Diagnostic trials are considered as one of the sub-segments of clinical trials. The other segments are interventional trials/treatment trials, prevention trials, observational trials, and therapeutic and non-therapeutic trials.
• Diagnostic trials are defined as trials that are conducted to find better tests or procedures for diagnosing a particular disease or condition.
• These tests are conducted on people who have signs or symptoms of the disease or condition being studied.
• To give an example of diagnostic trial, the Alliance for Clinical Trials in Oncology sponsored a diagnostic trial to study the effectiveness of lymph node mapping and sentinel lymph node lymphadenectomy in patients who were undergoing surgery to remove early-stage cancer of the mouth.
• The rationale driving this trial was to find out diagnostic procedures to detect cancer cells in sentinel lymph nodes that could help plan effective cancer treatment.