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Why do we need to conduct critical trails?
Clinical trials show us what works (and what doesn't) in medicine. They are the best way for doctors to learn what is safe and effective in treating diseases such as cancer.
Some doctors and scientists conducted what would now be considered clinical trials as far back as the late 1700s, but clinical trials were not widely used until the middle of the 20th century. Up until that time, doctors relied on their own experience in particular cases and on the teachings of those who came before them. Progress was slow, and very few medicines existed that could even be tested.
With the discovery of the first antibiotics and other drugs, doctors needed a reliable way to tell what worked from what didn't. They also needed ways to find out which of the countless remedies available at that time were safe for people to use. So they developed studies that tested, and often compared, treatments in a specific group of people. The results of these clinical trials proved to be more useful than relying on whether or not something worked in one or a few people.
In the US, new drugs and medical devices (but not dietary supplements) must be approved by the US Food and Drug Administration (FDA)
before they can be advertised or sold to the general public. The FDA began overseeing the safety of new treatments in the late 1930s but didn't require proof of effectiveness until the early 1960s. Today, drugs and medical devices must go through several phases of clinical trials (discussed below) before being approved for use.
Based on what we have learned about cancer in recent years, researchers can now develop new treatments in a more logical way and much faster than in the past. But it's still a time-consuming and difficult process.
Clinical trials are only a small part of the research that goes into developing a new treatment. Potential drugs, for example, first have to be discovered, purified, characterized, and tested in labs (in cell and animal studies) before ever reaching clinical trials. In all, about 1,000 potential drugs are tested before just one reaches the point of being tested in a clinical trial. On average, a new cancer drug has at least 6 years of research behind it before it even makes it to clinical trials. But the major holdup in making new cancer drugs available is the time it takes to complete clinical trials themselves. On average, about 8 years pass from the time a cancer drug enters clinical trials until it is approved.
Why so long? To establish safety and effectiveness, researchers look at each new treatment in several different studies. Only certain people are eligible to take part in each clinical trial. And cancer trials, by their very nature, take years to complete. It takes months, if not years, to see if a cancer treatment works in any one person.
The biggest barrier to completing studies is the shortage of people who take part. Fewer than 5% of adults with cancer will do so. According to the Pharmaceutical Research and Manufacturers of America (PhRMA), about 400 cancer medicines were being tested in clinical trials in 2005. Not all of these will prove to be useful, but those that are may be delayed in getting approved because the number of participants is so low.
The number one reason people give for not taking part in a clinical trial is that they didn't know the studies were an option for them. But there are many other reasons. Some people may want to take part but aren't eligible for some reason. Some people are uncomfortable with the idea of being a "subject" in a study. Others worry that they won't be treated fairly or could be harmed by an unproven treatment. Certainly these are understandable concerns. We have addressed them in more detail in the section "Should I Think About Taking Part in a Clinical Trial?"
One of the most important points in deciding if a clinical trial can be done is whether or not it would be ethical to ask patients to volunteer for an experimental treatment. Has the study been designed, as much as possible, to ensure the safety of the people involved? Would the participants receive a treatment that is at least as good as, and possibly better than, what they would get if they did not volunteer for the study? Scientific panels are set up to review and approve all clinical trials to make sure questions like these are answered before the researchers are allowed to enroll patients.
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