The last two Map of Biomedicine blog posts have introduced us to the clinical trial process. Clinical trials are the gold standard for determining whether a drug works, and are extremely important to make sure that drugs are only used in situations when they are known to help.
When people are faced with an illness -- whether it is a chronic condition or a life-threatening one -- the last thing they want to hear is that there is no treatment. Clinical trials are one way that patients can get access to treatments that are not broadly available. Patients who participate in trials are volunteering to be part of an experiment to test whether a drug works, and they often are hoping for some help with their condition.
But there are several other ways that patients can get access to medicines that aren’t approved for a particular disease.
One way is off-label use. The label in this case refers to the FDA label that describes how drugs should be prescribed and which talks about side effects and other things doctors and consumers should know. They are the big pieces of paper that are folded up in prescription packages that most people never read - but should. They are also available on-line in the FDA’s web site. As an example, look at the label for anti-cancer medicine Avastin. It is 35 pages long and contains a lot of information about how the drug works and how it was tested in clinical trials.
The first section of the label is called ‘Indications and Usage’ – this section explains the conditions that the medicine has been approved to treat. In the case of Avastin, it lists several different types of cancer, including lung cancer and colon cancer.
Avastin is a kind of drug called an angiogenesis inhibitor. Angiogenesis is the process of growing new blood vessels. As tumors grow, they need additional blood supply, so they have to be able to stimulate the growth of new blood vessels. Angiogenesis inhibitors slow this process and thus slow the growth of tumors.
However, cancers aren't the only diseases that are affected by blood vessel growth. There’s a disease of the eye called age-related macular degeneration (AMD) where blood vessel growth contributes to the loss of vision. For this reason Avastin has been used to treat AMD, even though it is not mentioned on the FDA label.
Off-label use is not officially overseen by the FDA, but it is effectively regulated in the United States by insurance companies and Medicare/Medicaid, since they decide which drugs and treatments they will pay for. Most people can’t afford to pay for drugs in their own, so this limits off-label use beyond what is generally accepted to be useful for patients.
In my next post I’ll talk about another way that patients can get access to unapproved drugs: compassionate use.
-- Will FitzHugh