Clinical Trials

Clinical Trials

Clinical Trials

What is a clinical trial?

A clinical trial is the next step after lab testing and animal studies. They are used to test a specific intervention [medical products (i.e., drugs or devices), procedures, or change to a participant’s behavior (i.e., diet) to determine its efficacy. Clinical trials are also used to compare a new intervention with ones that are already available. Some trials even compare two already available interventions to each other.

Why are clinical trials conducted?

The efficacy of a new product is not usually known, so investigators measure certain outcomes in the participants to determine the safety and efficacy of the product for treating a condition, syndrome, or disease.

Types of Clinical Trials

There are several types of clinical trials. Some of the most common types of trials are:

  • Diagnostic trials
    • Examine better tests/procedures for disease or condition diagnosis
  • Prevention trials
    • Explore ways to prevent a disease from occurring in people who have never had the disease or from returning in those that have had the disease
  • Quality of life trials
    • Identify and measure options to improve the comfort and quality of life for people with chronic illness
  • Screening trials
    • Test best ways to detect health conditions or diseases
  • Treatment trials
    • Test new treatments or treatment combinations or approaches to surgery, radiation therapy, or clinical management strategies
  • Behavioral trials
    • Testing of behavior change interventions
    • Behavior change is important in the prevention and treatment of many diseases, particularly diseases associated with unhealthy habits or activities (e.g., smoking)

Who runs clinical trials?

Clinical trials can be sponsored or funded by federal agencies, pharmaceutical companies, academic medical centers, or voluntary groups. However, the clinical trials are run by a principal investigator who is usually a medical doctor. She is joined by a research team made up of doctors, nurses, social workers, or other healthcare professionals.

Clinical Trial Phases

The clinical trial research process can be described by phases, each with a different purpose aimed at different questions.

  • Pre-clinical testing
    • Before a drug can be tested in humans, a safe dose must be determined; this is a main goal of pre-clinical studies.
  • Investigational New Drug Application
    • In the US, a pharmaceutical company must submit an application to the FDA’s Investigational New Drug (IND) program for permission to ship an experimental drug across state lines to clinical investigators. The FDA reviews the application to make sure that the drug is safe to test in humans in any planned clinical trials. IND approval only allows the drug to be tested in humans, but not yet for it to be marketed and sold in treatment of the disease.
  • Phase I
    • In this phase, the study assesses drug safety by determining what the drug’s most frequent and adverse effects are.
  • Phase II
    • In phase II, studies focus on drug effectiveness. This is whether a drug works in people who have a certain condition or disease.
  • Phase III
    • Here the study tests drug effectiveness on a larger scale in populations. This is used to determine the best drug dosage and see how the drug reacts in combination with other drugs.
  • Approval
    • After FDA approval is received for a drug to be put on the market for use in clinical care, studies are conducted to continue gathering information about a drug’s efficacy, optimal use, and safety in Phase IV trials (to study long-term effects) and post-marketing studies (to examine specific populations).
  • Post-marketing studies
    • These studies focus on special populations and the drug’s efficacy within these populations.

How long is a clinical trial?

Each trial in each step of the clinical research process varies in length depending on the study. Participants are told how long the trial will last before they enroll to participate.

Who can participate?

Eligibility to participate in a clinical trial depends on the trial’s inclusion criteria. Inclusion criteria determine who is eligible to be part of the trial. Criteria are a set of standards based on a patient characteristics such as type and stage of disease, gender, age, and prior treatment history.

What can I expect?

Most trials involve some risk but they may not be greater than those risks related to routine disease progression and medical care.

The effectiveness and safety of the product in the trial might not be known. Some trials may benefit participants medically, but others might not.

Study protocols vary and participants may have to undergo additional procedures, tests, or assessments during the course of the clinical trial.

The overall purpose of a clinical trial is to contribute to medical knowledge. These trials can affect the care of future patients.

What are the risks?

New treatments could have unexpected side effects and risks that are worse than that of the standard option of care.

Costs that a participant may have as a result of the study might not be covered by health insurance and managed care providers.

Even if you are seeing positive effects from the intervention, the intervention may not be approved by regulatory agencies.

Participants in randomized trials are assigned whether or not they will receive an intervention that is being tested. They cannot choose. “Randomized” means that a person is randomly assigned to an intervention group to receive treatment or to a control group to receive a “placebo” or usual care.

Additional doctor visits may be required.

How am I protected?

Each participant must provide informed consent to be part of a clinical trial. To make an informed decision, participants are provided with information on the study. In addition to this informed consent document, participants may receive recruitment materials, verbal instructions, or question and answer sessions.

To further protect the participant, an institutional review board (IRB) reviews, approves and monitors clinical trials and studies of drugs, biological products, and medical devices that are regulated by the FDA. The IRB ensures that a study is ethical and that the participants rights and welfare are protected.

Key questions to ask before you join a trial:

  1. What is being studied?
  2. What is the study length
  3. Will I know what intervention I receive during the trial? Who will know?
  4. Has the intervention been tested before? Why do investigators think this intervention will be effective?
  5. How does my current treatment compare to the proposed treatment I might get in the trial in terms of possible risks, side effects, and benefits?
  6. What will be required of me?
  7. Is hospitalization required?
  8. Will my participation be paid for? Will my expenses be reimbursed?
  9. Will I be able to continue receiving the intervention after the trial ends?
  10. Can I see or keep a copy of the results of the trial when it’s over?

Examples of Clinical Trials

Aspirin Dosing: A Patient-centric Trial Assessing Benefits and Long-Term Effectiveness (ADAPTABLE)

The ADAPTABLE trial is currently in progress. It is a three-year clinical trial involving heart disease patients across the U.S. to discover which of two aspirin doses is best for patients who have heart disease. It makes use of the National Patient-Centered Clinical Research Network (PCORnet) to recruit and enroll patients. It was the first study to harness PCORnet to achieve a large sample size and reduce study costs.
Key Information:

  • ADAPTABLE aims to uncover the risks and benefits of each of two common dosages of aspirin (81 mg versus 325 mg) to prevent heart disease

Bariatric Surgery

Bariatrics is the branch of medicine that deals with the causes, prevention, and treatment of obesity. This is a five-year clinical trial of 60,000 bariatric surgery patients enrolled from PCORnet to see the risks and benefits of the 3 most common bariatric procedures. The study also asked patients their opinions about:

  • whether to have bariatric surgery or not
  • what procedure is most recommended
  • follow-up care after surgery

Arthritis-Specific Clinical Trials

Safety Trial of Adalimumab in Rheumatoid Arthritis (STAR)

This study set out to evaluate the efficacy and safety of the drug adalimumab (Humira) given in combination with standard anti-rheumatic therapies such as conventional disease modifying anti-rheumatic drugs (DMARDs, such as methotrexate) and nonsteroidal anti-inflammatory drugs (NSAIDs such as ibuprofen) in patients with active rheumatoid arthritis that were not adequately responding to such standard therapies.

Key Information

  • Patients were randomly assigned to a placebo or to the treatment of 40 mg of adalimumab every other week and both groups continued their standard therapy.
  • It was a double-blind study, meaning neither patients nor researchers knew if the patient was receiving treatment or a placebo.
  • Patients and their symptoms were tracked over the course of 24 weeks.


  • 40 mg of adalimumab every other week is effective and safe in combination with standard anti-rheumatic therapies.

Comparison of combination therapy with single-drug therapy in early rheumatoid arthritis: a randomized trial

The study was a two-year trial where patients were randomized to receive either a combination therapy (sulphasalazine, methotrexate, hydroxychloroquine, and prednisolone) OR a single drug therapy (DMARD with or without prednisolone).

  • The combination therapy seemed to increase the efficacy of treatment in early rheumatoid arthritis patients.
  • It was also determined that it was better and not more hazardous than the single treatment therapy.

The Research on Actemra Determining Efficacy After Anti-TNF Failures Trial (RADIATE)

This study was a Phase III, randomized, double-blind, placebo controlled, parallel group study that aimed to find out whether tocilizumab (Actemra) and methotrexate was an effective treatment for RA patients whose disease had not improve when taking an anti-tumor necrosis factor (anti-TNF) medication. The trial was conducted throughout Australia, North America, Western Europe, and Latin America.


  • The study demonstrated that tocilizumab (TCZ) and methotrexate is effective in patients who did not have a response to anti-TNF agents.
  • Patients responded to this treatment regardless of the number of failed treatments they had had with anti-TNF agents.

The Tocilizumab in Combination With Traditional DMARD Therapy (TOWARD)

The TOWARD study followed more than 1,000 moderate-to-severe RA patients across the U.S., Asia, and Latin America to study the efficacy of tocilizumab (TCZ) taken every 4 weeks in combination with DMARDs. The treatment group was compared to a control group that received only DMARDs.


  • The study found that RA remission was achieved to a greater extent in the TCZ treatment group than the control group.