Clinical Trials Information Fact Sheet

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Clinical Trials Information Fact Sheet

Postby patoco » Thu Oct 19, 2006 12:53 pm

Understanding Clinical Trials

Pat O'Connor

Lymphedema People

http://www.lymphedemapeople.com

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I have often referred to the need for clinical trials to substantiate claims made by makers of various "would be" treatment modalities. With the surge of new proposed treatments available for lymphedema, it becomes even more important for us to insist on the process of clinical trials. This is also one of the foundations of what is known as evidence based medicine.

But, what exactly is a clinical trial, what does it do and what is its value?

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An Introduction to Clinical Trials

Choosing to participate in a clinical trial is an important personal decision. The following frequently asked questions provide detailed information about clinical trials. In addition, it is often helpful to talk to a physician, family members, or friends about deciding to join a trial. After identifying some trial options, the next step is to contact the study research staff and ask questions about specific trials.

What is a clinical trial?

A clinical trial (also clinical research) is a research study in human volunteers to answer specific health questions. Carefully conducted clinical trials are the fastest and safest way to find treatments that work in people and ways to improve health. Interventional trials determine whether experimental treatments or new ways of using known therapies are safe and effective under controlled environments. Observational trials address health issues in large groups of people or populations in natural settings.

Why participate in a clinical trial?

Participants in clinical trials can play a more active role in their own health care, gain access to new research treatments before they are widely available, and help others by contributing to medical research.

Who can participate in a clinical trial?

All clinical trials have guidelines about who can participate. Using inclusion/exclusion criteria is an important principle of medical research that helps to produce reliable results. The factors that allow someone to participate in a clinical trial are called "inclusion criteria" and those that disallow someone from participating are called "exclusion criteria". These criteria are based on such factors as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. Before joining a clinical trial, a participant must qualify for the study. Some research studies seek participants with illnesses or conditions to be studied in the clinical trial, while others need healthy participants. It is important to note that inclusion and exclusion criteria are not used to reject people personally. Instead, the criteria are used to identify appropriate participants and keep them safe. The criteria help ensure that researchers will be able to answer the questions they plan to study.

What happens during a clinical trial?

The clinical trial process depends on the kind of trial being conducted (See What are the different types of clinical trials?) The clinical trial team includes doctors and nurses as well as social workers and other health care professionals. They check the health of the participant at the beginning of the trial, give specific instructions for participating in the trial, monitor the participant carefully during the trial, and stay in touch after the trial is completed.

Some clinical trials involve more tests and doctor visits than the participant would normally have for an illness or condition. For all types of trials, the participant works with a research team. Clinical trial participation is most successful when the protocol is carefully followed and there is frequent contact with the research staff.

What is informed consent?

Informed consent is the process of learning the key facts about a clinical trial before deciding whether or not to participate. It is also a continuing process throughout the study to provide information for participants. To help someone decide whether or not to participate, the doctors and nurses involved in the trial explain the details of the study. If the participant's native language is not English, translation assistance can be provided. Then the research team provides an informed consent document that includes details about the study, such as its purpose, duration, required procedures, and key contacts. Risks and potential benefits are explained in the informed consent document. The participant then decides whether or not to sign the document. Informed consent is not a contract, and the participant may withdraw from the trial at any time.

What are the benefits and risks of participating in a clinical trial?

Benefits

Clinical trials that are well-designed and well-executed are the best approach for eligible participants to:

Play an active role in their own health care.

Gain access to new research treatments before they are widely available.

Obtain expert medical care at leading health care facilities during the trial.
Help others by contributing to medical research.

Risks

There are risks to clinical trials.

There may be unpleasant, serious or even life-threatening side effects to experimental treatment.

The experimental treatment may not be effective for the participant.

The protocol may require more of their time and attention than would a non-protocol treatment, including trips to the study site, more treatments, hospital stays or complex dosage requirements.
What are side effects and adverse reactions?

Side effects are any undesired actions or effects of the experimental drug or treatment. Negative or adverse effects may include headache, nausea, hair loss, skin irritation, or other physical problems. Experimental treatments must be evaluated for both immediate and long-term side effects.

How is the safety of the participant protected?

The ethical and legal codes that govern medical practice also apply to clinical trials. In addition, most clinical research is federally regulated with built in safeguards to protect the participants. The trial follows a carefully controlled protocol, a study plan which details what researchers will do in the study. As a clinical trial progresses, researchers report the results of the trial at scientific meetings, to medical journals, and to various government agencies. Individual participants' names will remain secret and will not be mentioned in these reports (See Confidentiality Regarding Trial Participants).

What should people consider before participating in a trial?

People should know as much as possible about the clinical trial and feel comfortable asking the members of the health care team questions about it, the care expected while in a trial, and the cost of the trial. The following questions might be helpful for the participant to discuss with the health care team.

Some of the answers to these questions are found in the informed consent document.

What is the purpose of the study?
Who is going to be in the study?
Why do researchers believe the experimental treatment being tested may be effective? Has it been tested before?
What kinds of tests and experimental treatments are involved?
How do the possible risks, side effects, and benefits in the study compare with my current treatment?
How might this trial affect my daily life?
How long will the trial last?
Will hospitalization be required?
Who will pay for the experimental treatment?
Will I be reimbursed for other expenses?
What type of long-term follow up care is part of this study?
How will I know that the experimental treatment is working? Will results of the trials be provided to me?
Who will be in charge of my care?
What kind of preparation should a potential participant make for the meeting with the research coordinator or doctor?

Plan ahead and write down possible questions to ask.

Ask a friend or relative to come along for support and to hear the responses to the questions.

Bring a tape recorder to record the discussion to replay later.
Every clinical trial in the U.S. must be approved and monitored by an Institutional Review Board (IRB) to make sure the risks are as low as possible and are worth any potential benefits. An IRB is an independent committee of physicians, statisticians, community advocates, and others that ensures that a clinical trial is ethical and the rights of study participants are protected. All institutions that conduct or support biomedical research involving people must, by federal regulation, have an IRB that initially approves and periodically reviews the research.

Does a participant continue to work with a primary health care provider while in a trial?

Yes. Most clinical trials provide short-term treatments related to a designated illness or condition, but do not provide extended or complete primary health care. In addition, by having the health care provider work with the research team, the participant can ensure that other medications or treatments will not conflict with the protocol.

Can a participant leave a clinical trial after it has begun?

Yes. A participant can leave a clinical trial, at any time. When withdrawing from the trial, the participant should let the research team know about it, and the reasons for leaving the study.

Where do the ideas for trials come from?

Ideas for clinical trials usually come from researchers. After researchers test new therapies or procedures in the laboratory and in animal studies, the experimental treatments with the most promising laboratory results are moved into clinical trials. During a trial, more and more information is gained about an experimental treatment, its risks and how well it may or may not work.

Who sponsors clinical trials?

Clinical trials are sponsored or funded by a variety of organizations or individuals such as physicians, medical institutions, foundations, voluntary groups, and pharmaceutical companies, in addition to federal agencies such as the National Institutes of Health (NIH), the Department of Defense (DOD), and the Department of Veteran's Affairs (VA). Trials can take place in a variety of locations, such as hospitals, universities, doctors' offices, or community clinics.

What is a protocol?

A protocol is a study plan on which all clinical trials are based. The plan is carefully designed to safeguard the health of the participants as well as answer specific research questions. A protocol describes what types of people may participate in the trial; the schedule of tests, procedures, medications, and dosages; and the length of the study. While in a clinical trial, participants following a protocol are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment.

What is a placebo?

A placebo is an inactive pill, liquid, or powder that has no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the experimental treatment's effectiveness. In some studies, the participants in the control group will receive a placebo instead of an active drug or experimental treatment.

What is a control or control group?

A control is the standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either a standard treatment for the illness or a placebo.

What are the different types of clinical trials?

Treatment trials test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.

Prevention trials look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vitamins, vaccines, minerals, or lifestyle changes.

Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.

Screening trials test the best way to detect certain diseases or health conditions.

Quality of Life trials (or Supportive Care trials) explore ways to improve comfort and the quality of life for individuals with a chronic illness.

What are the phases of clinical trials?

Clinical trials are conducted in phases. The trials at each phase have a different purpose and help scientists answer different questions:

In Phase I trials, researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.

In Phase II trials, the experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.

In Phase III trials, the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.

In Phase IV trials, post marketing studies delineate additional information including the drug's risks, benefits, and optimal use.

What is an "expanded access" protocol?
Most human use of investigational new drugs takes place in controlled clinical trials conducted to assess safety and efficacy of new drugs. Data from the trials can serve as the basis for the drug marketing application. Sometimes, patients do not qualify for these carefully-controlled trials because of other health problems, age, or other factors. For patients who may benefit from the drug use but don't qualify for the trials, FDA regulations enable manufacturers of investigational new drugs to provide for "expanded access" use of the drug. For example, a treatment IND (Investigational New Drug application) or treatment protocol is a relatively unrestricted study. The primary intent of a treatment IND/protocol is to provide for access to the new drug for people with a life-threatening or serious disease for which there is no good alternative treatment. A secondary purpose for a treatment IND/protocol is to generate additional information about the drug, especially its safety. Expanded access protocols can be undertaken only if clinical investigators are actively studying the experimental treatment in well-controlled studies, or all studies have been completed. There must be evidence that the drug may be an effective treatment in patients like those to be treated under the protocol. The drug cannot expose patients to unreasonable risks given the severity of the disease to be treated.

Some investigational drugs are available from pharmaceutical manufacturers through expanded access programs listed in ClinicalTrials.gov. Expanded access protocols are generally managed by the manufacturer, with the investigational treatment administered by researchers or doctors in office-based practice. If you or a loved one are interested in treatment with an investigational drug under an expanded access protocol listed in ClinicalTrials.gov, review the protocol eligibility criteria and location information and inquire at the Contact Information number.

See "FDA Finds New Ways to Speed Treatments to Patients" for more details. Link to: http://www.fda.gov/fdac/special/newdrug/speeding.html

http://www.clinicaltrials.gov/ct/info/whatis#whatis

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Types of clinical trials

The most commonly performed clinical trials evaluate new drugs, medical devices, biologics, or other interventions on patients in strictly scientifically controlled settings, and are required for regulatory authority (in the USA, the Food and Drug Administration; in the EU, the European Medicines Agency; in Japan, the Ministry of Health, Labour and Welfare (Japan)) approval of new therapies. Trials may be designed to assess the safety and efficacy of an experimental therapy, to assess whether the new intervention is better than standard therapy, or to compare the efficacy of two standard or marketed interventions. The trial objectives and design are usually documented in a clinical trial protocol. In USA there is a 50% tax credit on clinical trials.

To be ethical, they must involve the full and informed consent of participating human subjects. They are closely supervised by appropriate regulatory authorities. All interventional studies must be approved by an ethics committee (in the USA, this body is the Institutional Review Board) before permission is granted to run the trial.

The study design that provides the most compelling evidence of a causal relationship between the treatment and the effect, is the randomized controlled trial. Observational studies in epidemiology such as the cohort study and the case-control study are clinical studies in that they involve human participants, but provide less compelling evidence than the randomized controlled trial. The major difference between clinical trials and observational studies is that, in clinical trials, the investigators manipulate the administration of a new intervention and measure the effect of that manipulation, whereas observational studies only observe associations (correlations) between the treatments experienced by participants and their health status or diseases. These are fundamental distinctions in evidence-based medicine.

Currently some Phase II and most Phase III drug trials are designed to be randomized, double-blind, and placebo-controlled. This means that each study subject is randomly assigned to receive one of the treatments, which might be the placebo. Neither the subjects nor scientists involved in the study know which study treatment is being administered to any given subject; and, in particular, none of those involved in the study know which subjects are being administered a placebo. Of note, during the last ten years or so it has become a common practice to conduct "active comparator" trials (also known as "active control" trials) - in other words, when a treatment exists that is clearly better than doing nothing (i.e. the placebo) for the subject, the alternate treatment would be a standard-of-care therapy.

While the term clinical trials is most commonly associated with large randomized studies, many clinical trials are small. They may be "sponsored" by single physicians or a small group of physicians, and are designed to test simple questions. Other clinical trials require large numbers of participants followed over long periods of time, and the trial sponsor is more likely to be a commercial company or a government, or other academic, research body. It is sometimes necessary to organize multicenter trials. Often the centres taking part in such trials are in different countries (in which case they may be termed international clinical trials).

The number of patients enrolled in the study also has a large bearing on the ability of the trial to reliably detect an effect of a treatment. This is described as the "power" of the trial. It is usually expressed as the probability that, if the treatments differ in their effect on the outcome of interest, the statistical analysis of the trial data will detect that difference. The larger the sample size or number of participants, the greater the statistical power. However, in designing a clinical trial, this consideration must be balanced with the greater costs associated with larger studies. The power of a trial is not a single, unique value; it estimates the ability of a trial to detect a difference of a particular size (or larger) between the treated and control groups. For example, a trial of a lipid-lowering drug with 100 patients per group, might have a power of .90 to detect a difference between active and placebo of 10 mg/dL or more, but only have a power of .70 to detect a difference of 5 mg/dL.

Phases

Pharmaceutical clinical trials are commonly classified into four phases, and the drug-development process will normally proceed through all four stages over many years. If the drug successfully passes through the first three phases, it will usually be successfully approved for use in the general population.

Before pharmaceutical companies start clinical trials on drugs, extensive pre-clinical studies are conducted.

Phase I
Phase I trials are the first-stage of testing in human subjects. Normally a small (20-80) group of healthy volunteers will be selected. This phase includes trials designed to assess the safety (Pharmacovigilance), tolerability, pharmacokinetics, and pharmacodynamics of a therapy. These trials are almost always conducted in an inpatient clinic, where the subject can be observed by full-time medical staff. The subject is usually observed until several half-lives of the drug have passed. Phase I trials also normally include dose-ranging studies so that doses for clinical use can be refined. The tested range of doses will usually be a small fraction of the dose that causes harm in animal testing. Phase I trials most often include healthy volunteers, however there are some circumstances when patients are used, such as with oncology (cancer) and HIV drug trials. In Phase I trials of new cancer drugs, for example, patients with advanced (metastatic) cancer are used. These trials are usually offered to patients who have had other types of therapy and who have few, if any, other treatment choices.

There are two specific kinds of Phase I trials - SAD studies, and MAD studies.

SAD - Single Ascending Dose studies are those in which groups of three or six patients are given a small dose of the drug and observed for a specific period of time. If they do not exhibit any adverse side effects, a new group of patients is then given a higher dose. This is continued until intolerable side effects start showing up, at which point the drug is said to have reached the Maximum tolerated dose (MTD).

MAD - Multiple Ascending Dose studies are conducted to better understand the pharmacokinetics/pharmacodynamics of the drug. In these studies, a group of patients receives a low dose of the drug and the dose is subsequently escalated up to a predetermined level. Samples (of blood, and other fluids) are collected at various time points and analyzed to understand how the drug is processed within the body.

Phase II
Once the initial safety of the therapy has been confirmed in Phase I trials, Phase II trials are performed on larger groups (20-300) and are designed to assess clinical efficacy of the therapy; as well as to continue Phase I assessments in a larger group of volunteers and patients. The development process for a new drug commonly fails during Phase II trials due to the discovery of poor efficacy or toxic effects.

Phase II studies are sometimes divided into Phase IIA and Phase IIB. Phase IIA is specifically designed to assess dosing requirements, whereas Phase IIB is specifically designed to study efficacy.

Some trials combine Phase I and Phase II into a single trial, monitoring both efficacy and toxicity.

Phase III
Phase III studies are large double-blind randomized controlled trials on large patient groups (300–3,000 or more depending upon the condition) and are aimed at being the definitive assessment of the efficacy of the new therapy, in comparison with current 'Gold Standard' treatment. Phase III trials are the most expensive, time-consuming and difficult trials to design and run; especially in therapies for chronic conditions. Once a drug has proven satisfactory over Phase III trials, the trial results are usually combined into a large document containing a comprehensive description of the methods and results of human and animal studies, manufacturing procedures, formulation details, and shelf life. This collection of information makes up the "regulatory submission" that is provided for review to various regulatory authorities in different countries, such as the Therapeutic Goods Administration (TGA) in Australia, the European Medicines Agency (EMEA) or the Food and Drug Administration (FDA) in the United States for marketing approval.

It is also common practice with many drugs whose approval is pending, that certain phase III trials will continue in an attempt at "label expansion.” In other words, proving additional efficacy for uses beyond the original use for which the drug was designed. While not required in all studies, it is typically expected that there be at least two successful phase III trials, proving a drug's safety and efficacy, for approval from the standard regulatory agencies (FDA, TGA, EMEA, etc.). Though the current trend in recent months seems to be a move toward adaptive (live, changing) studies to expedite the process, there are no formal regulations for these trials in the pharmaceutical industry as of yet.

Phase IV
Phase IV trials involve the post-launch safety surveillance and ongoing technical support of a drug. Phase IV studies may be mandated by regulatory authorities or may be undertaken by the sponsoring company for competitive or other reasons. Post-launch safety surveillance is designed to detect any rare or long-term adverse effects over a much larger patient population and timescale than was possible during the initial clinical trials. Such adverse effects detected by Phase IV trials may result in the withdrawal or restriction of a drug - recent examples include cerivastatin (brand names Baycol and Lipobay), troglitazone (Rezulin) and rofecoxib (Vioxx).

References
Rang HP, Dale MM, Ritter JM, Moore PK (2003). Pharmacology 5 ed. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4
Finn R, (1999). Cancer Clinical Trials: Experimental Treatments and How They Can Help You., Sebastopol: O'Reilly & Associates. ISBN 1-56592-566-1
Chow S-C and Liu JP (2004). Design and Analysis of Clinical Trials : Concepts and Methodologies, ISBN 0-471-24985-8
Pocock SJ (2004), Clinical Trials: A Practical Approach, John Wiley & Sons, ISBN 0-471-90155-5

http://en.wikipedia.org/wiki/Clinical_trial
Last edited by patoco on Sat Feb 03, 2007 6:14 pm, edited 1 time in total.
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Postby patoco » Sat Feb 03, 2007 6:13 pm

reviewed 02/03/07
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