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Clinical trials: A chance to try evolving therapies
How much will you know about the treatment being investigated?
It's crucial that you have enough information about the study and the treatment being investigated to make a well-informed decision. To ensure that you do, the study facilitators provide what's called an informed consent document. You must read and sign an informed consent form before being allowed into the trial. This informed consent document contains information you need to know about the study before deciding whether to participate. Some of the information on an informed consent document includes:
- What will happen during the clinical trial, including tests you may be given
- Known risks and benefits of the experimental treatment
- How long you'll be expected to participate in the clinical trial
- Other treatments that might help you instead of the treatment being tested
- Whom to contact with questions
The form must explain this information in words you can understand. Researchers aren't allowed to pressure you into signing up for a trial. Signing the informed consent form means you agree to participate in the trial. It isn't a contract. If you later decide to leave the study, you may do so without any penalty.
If your child will be enrolled in a clinical trial, you will go through the informed consent process together. As the parent or guardian, you will have to give permission for your child to participate. Depending on your child's age, researchers may also ask your child directly if he or she agrees to be in the study.
Questions to ask before participating in a clinical trial
If you have any questions about the trial, ask before you agree to participate. Questions you might want to ask include:
- Who is in charge of this study?
- Do the people running the study have a vested interest (conflict of interest) in the outcome?
- What is this study trying to find out?
- What will be expected of me?
- Is it possible that I might receive a placebo?
- What benefits or risks can I expect if I take part in this study?
- How long will the study last?
- What happens if my condition gets worse during the study?
- Can I continue seeing my own doctor during the study?
- Will I need to pay for any part of the study, including doctor visits and routine tests?
- Who pays if I am unexpectedly injured in the trial?
- How will participation in the study affect my daily life?
- What happens at the end of the study?
- Will I be told the results of the study? When?
- Who will know that I'm participating in the study?
How are trials conducted?
Clinical trials follow a scientific action plan called a protocol. The protocol explains what will be done in the study and why. It outlines:
- Who may participate
- How many people will take part
- What the treatment plan entails
- The type and frequency of tests
- How the results will be measured
- The reasons that a study may be stopped
- The situations in which researchers may stop giving the treatment to participants
- The likely or known side effects of the treatment
- The possible benefits of the treatment
To ensure the safety of people in the study, the organization that sponsors the study, such as the medical center or clinic where the work will be done, must approve the protocol. In addition, an institutional review board (IRB) at each study site reviews the protocol. The IRB includes people from the community as well as health care professionals. It reviews all protocols to be sure that participants are treated humanely and ethically. The IRB also looks at issues such as whether the likely benefit of the treatment is worth its risk. If the risks to participants are found to be too great, the IRB can require changes to the study protocol or even reject the study altogether. When reviewing a protocol, the IRB also checks to see if any of the researchers have substantial conflicts of interest.
A clinical trial may also have a data safety monitoring board overseeing it. This board is composed of people who aren't directly involved in conducting the study. The data safety monitoring board can stop the study at any time if it sees that the treatment isn't working or it's causing too many side effects. A trial can also be halted by the data safety monitoring board if the treatment is proving to be better than the standard treatment. It may be working so well that it should be made available to people outside of the clinical trial.
What are the types of clinical trials?
Clinical research takes place in steps, and each step has a different focus:
Phase 0
Phase 0 trials are a relatively new type of study. They're designed to weed out treatments that aren't promising before they go on to phase I research. These trials are very small — typically 10 to 12 people — and usually focus on how a drug acts in the body and how the body reacts to it.
Phase I
This is typically the first step in testing in humans. At this point researchers study:
- How much of the treatment to give
- How it should be given and how often
- What is the highest dose that can be given safely
- How the body reacts to the treatment
- Any harmful side effects
Earlier studies have often been done only in animals, so the new treatment may pose some risks when first tried in humans. Researchers try to minimize these risks by starting with a very small dose and then increasing it only if no or few side effects occur. Phase I trials usually include a limited number of people — typically 20 to 80.
Phase II
This step focuses on determining whether a new approach works as intended. For example, does it shrink a tumor? Researchers also monitor participants for common short-term side effects that occur with the therapy. Some things aren't yet known about the treatment, so risks are still present. Several hundred people may participate in a phase II study.
Phase III
If a treatment has shown promise in phases I and II, it can move on to this phase. Participants are often randomly assigned, meaning neither you nor your doctor can choose which treatment you receive — the experimental treatment or the standard treatment. Randomization helps to avoid bias in the study's results.
Phase III trials provide more information about the safety of the experimental treatment and demonstrate whether the standard or the experimental treatment has better survival rates and fewer side effects. These trials usually include several hundred to several thousand people. Large trials make it easier to estimate what would happen if the experimental treatment were available to everyone with the condition.
If a treatment performs well in a phase III trial, the researchers may submit an application to the Food and Drug Administration (FDA) asking permission to make it available to the public. The FDA approval process generally takes about a year. The process is quicker for priority drugs — drugs that provide a significant advance in treatment for a life-threatening condition. The FDA tries to rule on these within six months.
Phase IV
In some cases, research continues even after the FDA has approved a treatment. This research, sometimes called post-marketing research, tracks side effects and results in people receiving the newly approved treatment. Phase IV studies aren't required for every treatment, but the FDA can ask a manufacturer to conduct a phase IV trial to further evaluate long-term safety and effectiveness. Companies may also choose to do phase IV research to compare their product with a competitor's product. Several hundred to several thousand people may take part in a phase IV study.
Deciding to participate
Researchers need volunteers for clinical trials — healthy people as well as those at risk of or diagnosed with a disease. By participating, you help researchers find new ways to fight disease. Volunteering is also a way to access treatment that otherwise isn't available. If you're considering a clinical trial because you have been diagnosed with a disease, it's important to take time to learn about your condition and your treatment options. Talk with your doctor and other health care providers, and discuss your options with those close to you.
Previous page(2 of 2)
- Clinical trials: Questions and answers. National Institutes of Health. >http://www.cancer.gov/cancertopics/factsheet/Information/clinical-trials. Accessed May 15, 2009.
- Basic questions and answers about clinical trials. U.S. Food and Drug Administration. http://www.fda.gov/oashi/clinicaltrials/clintrialdoc.html. Accessed May 15, 2009.
- Inside clinical trials: Testing medical products in people. U.S. Food and Drug Administration. http://www.fda.gov/fdac/special/testtubetopatient/trials.html. Accessed May 15, 2009.
- How to enroll in a clinical trial. National Cancer Institute. http://bethesdatrials.cancer.gov/general-public/index.asp. Accessed May 15, 2009.
- How is a clinical trial planned and carried out? National Cancer Institute. http://www.cancer.gov/clinicaltrials/learning/how-trials-are-done. Accessed May 15, 2009.
- A guide to understanding informed consent. National Cancer Institute. http://www.cancer.gov/clinicaltrials/conducting/informed-consent-guide. Accessed May 20, 2009.
- The FDA's drug review process: Ensuring drugs are safe and effective. U.S. Food and Drug Administration. http://www.fda.gov/Drugs/ResourcesForYou/Consumers/ucm143534.htm. Accessed July 17, 2009.
- Mangskau TK (expert opinion). Mayo Clinic, Rochester, Minn., July 16, 2009.
- New approaches to cancer drug development and clinical trials: Questions and answers. National Cancer Institute. http://www.cancer.gov/newscenter/pressreleases/PhaseZeroNExTQandA. Accessed July 17, 2009.
