Understanding Cancer Clinical Trials

February 19, 2019

What do patients need to know when deciding whether a clinical trial is right for them and their cancer?

Clinical trials provide data that prove whether a new treatment is better than the standard therapy. They could offer alternatives if patients have few treatment options or if they’re seeking a treatment with the potential of being more beneficial than the standard treatment. Choosing a clinical trial might mean patients can find an option with fewer toxicities than the one being offered or one that is more convenient, such as an oral medication or one with a shorter treatment time. Although an increasing number of investigational cancer drugs are being approved by the Food and Drug Administration each year, the process is still lengthy and complex. If patients can navigate the process, they might find a good option, but it’s important to understand the phases involved in clinical trials and the potential benefit.

Phase 0 trials are the first to move a drug out of the laboratory and into people. Their goal is to determine how the body handles a specific drug. These trials are very small, including only 10 to 15 people.

Phase 1 trials enroll a small number of patients to study side effects and establish a safe dosage for a potential treatment. Phase 1 studies also evaluate how a new treatment should be given (for example, if a new drug is best taken orally or injected into the bloodstream or muscle), how often it should be administered and the most effective dose with the fewest or least severe side effects. Most patients who enter phase 1 trials have limited treatment options or do not improve with standard therapies. This phase is not designed to determine the effectiveness of the treatment.

Phase 2 trials continue to test the safety of a treatment while beginning to evaluate how well it works. These trials are usually limited to a specific cancer that showed benefit with the treatment in earlier trials.

Phase 3 studies compare the experimental drug, combination of drugs, regimen of radiation therapy or surgical procedure with the current standard to determine if it is better. Enrollment is often in the hundreds to thousands across multiple locations. Typically, a participant is randomly assigned to the standard treatment or the new treatment (called randomization). Patients who are not randomized to the experimental treatment will receive identified standard treatments.

Informed Consent

Phase 4 trials are sometimes referred to as real-world studies, because they paint a picture of how a drug works outside of a strictly regulated clinical trial. Some, but not all, of these trials occur after a drug has been approved by the FDA. Some goals of phase 4 trials are to learn more about a drug’s effectiveness, safety and side-effect profile. These trials also help determine how the medication works when given alongside other treatments, how the therapy compares to others on the market and whether or not it is cost-effective. Phase 4 investigations are large, including several hundreds or thousands of patients.Before enrolling in a clinical trial, patients are asked to sign an informed consent document that states they understand the purpose of the research and its risks and benefits, as well as their rights as patients. Patients should keep a copy of the informed consent document with their medical records. No informed consent document can ask patients to waive their legal rights or release the trial’s research team, trial sponsor, drug manufacturer or institution from liability for negligence.

Covering the Cost

Patients are allowed time to discuss the informed consent documents with family, friends or their physicians and to ask follow-up questions of the research team. As the trial progresses, the research team will continue to provide information and updates. It is important to understand that because the treatment is experimental, the outcomes and side effects are not always foreseeable, although any predicted risks should be explained in detail beforehand.Patients should discuss the costs associated with the trial with the research team and ask what would be covered by insurance. In most trials‚ the therapy under investigation is provided at no cost to the participant. Routine costs, such as hospital stays, outpatient appointments and tests done during a trial, are often covered by insurance or Medicare if the trial meets certain criteria.

Searching for a Clinical Trial

A provision in the Affordable Care Act, effective in 2014, prohibits new health plans from denying coverage for routine care that the plan would otherwise provide just because a person with cancer is enrolled in a clinical trial. The law also prohibits insurers from dropping coverage because a person chooses to participate in a clinical trial. Patients considering a clinical trial might also want to calculate the cost of travel and lodging if the site of the trial is distant, especially if the trial extends over several weeks or months and frequent trips are needed. Some institutions and nonprofit organizations can help with certain expenses for travel and housing (see page 90).No single resource lists every clinical trial, but ClinicalTrials.gov is the most comprehensive and allows searching by tumor type, location and other factors. The process might involve searching the Web, calling pharmaceutical companies or asking a doctor or cancer center for information.

Patients should begin with their oncologist‚ who not only can tell them if something is available locally‚ but also give them resources on what is happening in other parts of the country. Although it could be time-consuming to search for clinical trials at each location, patients will probably want to start with facilities closest to home. Those who are looking for a particular drug might want to contact the pharmaceutical company directly for the best information.


Before a drug can be approved by the Food and Drug Administration for use, it must pass a number of tests to prove its safety and effectiveness.

Fewer trial locations will be available for drugs in early-phase testing, so patients might have better luck with late-phase trials, which are conducted in multiple sites across the country.

Each trial has its own eligibility criteria and often has restrictions based on the type and stage of cancer‚ age of the patients‚ previous treatments received and current health status. Patients should have their medical histories accessible when searching for clinical trials because eligibility requirements could disqualify them from participating. Once they have found a number of trials for which they possibly qualify, patients should discuss them with their doctors and contact the study coordinators.