The standard cancer treatments of today came from yesterday’s clinical trials.
The American Society of Clinical Oncology (ASCO), the major organization for cancer specialists, has identified the five most important accomplishments made through clinical trials over the past 50 years of ASCO’s history:
• Chemotherapy cures for Hodgkin lymphoma; 90% of patients with Hodgkin’s disease can now be cured of the disease regardless of whether it is diagnosed early or in an advanced stage
• The human papilloma virus (HPV) vaccine (e.g. Gardasil®, Cervarix®), which can prevent cervical cancer
• A targeted drug (Gleevec® and others) for chronic myelogenous leukemia (CML) that has made CML a chronic, manageable disease for many patients and is used for other cancers as well
• The three-drug regimen (the Einhorn regimen, which includes cisplatin, bleomycin, and vinblastine) that cures almost 100% of men with advanced testicular cancer
• Anti-nausea drugs such as Zofran that have improved the quality of life for people with cancer
All of these discoveries were made through carefully designed clinical trials, making these trials an extremely important option for people with cancer to consider.
Phases of Clinical Trials
In phase I trials, researchers study the safety of a new drug or drug combination or a new dose of a drug. Phase I cancer trials usually only include a small group of 15 to 30 patients, and they may have any tumor type. This type of study looks at safety and any side effects or toxicities that might occur with the treatment. In phase I trials, researchers try to find the lowest dose that will still be effective, and determine which patients are able to tolerate the drug. These trials usually take place in research centers, where patients can be closely monitored.
In phase II trials, the new drug or treatment is given to a larger group of people (but generally fewer than 100) to see if it is effective and to learn more about its safety. Like phase I studies, phase II trials are usually conducted at research centers, such as large teaching hospitals and cancer centers. In some phase II studies, patients may be randomized. This means patients in the trial are selected by chance to get either the new treatment being studied or one that is already being used to treat their type of cancer. In order to avoid influencing the results, patients (and often their doctors) do not know which group they are in. Usually, there are limitations in phase II trials so that the drug can only be given to patients with a specific disease or a particular patient population. Randomized clinical trials are considered the most reliable way of determining which treatments work best.
In phase III trials, the study drug or treatment being tested is given to an even larger group of people (often as many as 1,000 to 3,000). During this phase, researchers are able to:
• Confirm how well the treatment works against the cancer
• Learn about side effects they might not have seen during earlier phases with fewer patients
• Compare the new treatment with currently used standard treatments
• Collect information that will allow the new drug or treatment to be used safely
In phase III trials, patients are randomized, as described above. In cancer clinical trials, patients are generally not given a placebo (a look-alike pill or liquid that contains no active ingredient). A placebo is only used when there is no standard treatment against which a new treatment can be compared. Phase III studies are often carried out in the community by local doctors in private practice, community hospitals, or designated cancer centers. Because phase III trials involve large numbers of people, doctors can better understand how a treatment will work in people with many different health issues.
In phase IV trials, researchers study drugs after they have been approved by the FDA. Phase IV trials are designed to learn more about the treatment’s risks and benefits and the best way to use it. These studies help doctors understand how safe and useful the treatment will be over the long term.
There are also studies with very little risk that do not have an active drug or technology to test, such as quality-of-life studies. In these studies, researchers just want to learn more about patients’ quality of life, and the studies can include almost anyone with cancer.