What Are Clinical Trials? 2017-05-01T17:52:45+00:00


Medications and medical devices are being developed everyday by pharmaceutical, biotechnology and medical device companies to prevent and treat disease. 

Additionally, new technologies and diagnostic tests are constantly in development to improve the diagnostic process that doctors use to determine which treatments are best for an individual’s symptomatology. 

Part of the development process, once it has been tested in the lab, is to test on people. When a treatment reaches this point in the development process, it enters under heavy scrutiny and regulation by the FDA and Institutional Review Boards (IRBs) to ensure the safety of all participants. At this point, the initial development process has come to an end and the human testing phases of research begin.  

Goals of Research

  • Is the treatment correctly indicated for the relief of symptoms?
  • How effective is the treatment?
  • What percentage of the volunteers respond to the treatment?
  • Are there drug to drug interactions?
  • Is the treatment safe for use?
  • Are there side effects to the treatment?
  • What are the Pharmacokinetics & Pharmacodynamic activity of the treatment?

DaVinci Research Institute

Pharmaceutical companies have hundreds of sites located all throughout the world, that conduct very strictly regulated trials to gather this information. Dr. Marsella has been one of these sites for the past 20+ years. These sites, sprinkled across the globe gather thousands of volunteers for Phase I through Phase IV studies. Copious amounts of information and data are collected, and volunteers are given a chance to try a potential new treatment for the disease from which the manufacturer is applying for approval or clearance from the FDA.


There are four main phases of testing medications. Phase I through Phase IV clinical molecule or device trials will hopefully lead a treatment to final approval by the FDA thereby allowing that treatment to enter the commercial marketplace, making it readily available to the general public. The goal of Phase I-IV trials is to get an idea of how the public will respond to the treatment. They are looking at its safety, and efficacy. Other information, such as side effects, interactions, and pharmacogenomics information are also gathered during these phases of testing.

  • Treatment is given to a small group of healthy people
  • Evaluates safety for in healthy individuals
  • Trials occur in an in-patient hospital setting
  • Initial look at pharmacokinetics and pharmacodynamics of the treatment
  • A safe dose range is determined
  • Evaluation of potential side-effects of treatment
Phase I
Phase II
  • If treatment passes Phase I, it progresses to Phase II
  • Conducted on a larger group of people who have a specific disease or symptom
  • Further look into pharmacokinetics and pharmacodynamics of treatment
  • Looks more closely at effectiveness of treatment
  • Further evaluates safety of treatment, this time in individuals who have a specific disease or symptom
  • If the treatment passes Phase II, it progresses to Phase III
  • Much larger group of volunteers, that suffer from very specific symptoms, that are otherwise generally healthy
  • Heavy emphasis is given to effectiveness of treatment
  • Comparisons of treatment to commonly prescribed treatments are investigated
  • Further evaluation of safety
  • In-depth monitoring of side-effects
Phase III




 FDA Approval is then applied for by the pharmaceutical company. If approved or cleared, then the molecule or device moves on to Phase IV testing. If not, the pharmaceutical company may decide to continue Phase III testing or to discontinue the trials and move on to another treatment for the indication. All molecules or devices move on to Phase IV testing once approved or cleared by the FDA.



Phase IV studies, often called Post Marketing Surveillance Trials, are conducted after a molecule or devicehas been approved or cleared for consumer sale.  Phase IV studies can result in a molecule or device being taken off the market or restrictions of use could be placed on the product depending on the findings in the study. Pharmaceutical companies have several objectives at this stage: 

  • to compare the treatment with other treatments already in the market
  • to monitor long-term effectiveness & impact on a patient’s quality of life
  • to determine the cost-effectiveness relative to other traditional & new therapies