Two decades ago, if you had moderate to severe Crohn's, there were few treatment options. In the late 1990s, however, the first in a new class of treatment options emerged for Crohn's disease. Referred to as biologic response modifiers, biologic agents, or simply biologics, these drugs target specific parts of an overactive immune system to reduce inflammation.
Biologics not only relieve Crohn's symptoms but also can bring about remission and keep you in remission. They are indicated for use when someone has moderately to severely active Crohn’s disease and has not responded well to other Crohn’s disease treatments. Many people with Crohn's now live with significantly fewer symptoms, but may worry about side effects. Here's a look at the risks and benefits of biologics.
How Biologics Work
In Crohn's disease, an overactive immune system causes inflammation and damage to the digestive tract. Made from living organisms, biologics work just like substances made by the body’s immune system and can help control the immune system response.
Four biologics are FDA approved for Crohn's. Three of the four block a protein called tumor necrosis factor (TNF) that's involved in inflammation. These drugs are often called anti-TNF drugs or TNF inhibitors. They include Cimzia (certolizumab), Humira (adalimumab), and Remicade (infliximab).
The fourth medication, Tysabri (natalizumab), is called an integrin receptor antagonist. It blocks certain types of white blood cells that are involved in inflammation.
Biologics and Side Effects
Because they suppress the immune system, all biologics carry an increased risk of infections, which in rare cases can be serious. Cimzia, Humira, and Remicade carry a boxed warning for increased risk of serious infections leading to hospitalization or death. If someone taking a biologic develops a serious infection, the drug should be discontinued. People with tuberculosis, heart failure, or multiple sclerosis should not take biologics because they can bring on these conditions or make them worse.
In rare cases, some people taking TNF inhibitors have developed certain cancers such as lymphoma. Lymphoma is a type of cancer that affects the lymph system, which is part of the body’s immune system.
Tysabri increases the risk of a very rare but potentially fatal brain infection called progressive multifocal leukoencephalopathy (PML). Tysabri also can cause allergic reactions and liver damage. Tysabri should not be used at the same time as other treatments that suppress the immune system or TNF inhibitors.
However, most infections that occur with biologic use are far less serious, says Richard Bloomfeld, MD, associate professor of medicine and director of the Inflammatory Bowel Disease Program at Wake Forest University School of Medicine in Winston Salem, N.C. "Infections such as colds, upper respiratory tract infections, and urinary tract infections are common and don't necessarily alter our treatment of Crohn's."
Other common side effects from biologic use include headache, flu-like symptoms, nausea, rash, injection site pain, and infusion reactions.
Risks From Conventional Treatment
So who should take a biologic for Crohn's? Many gastroenterologists reserve these drugs for people who have not responded to conventional medications that suppress the immune system. But some gastroenterologists may treat Crohn's more aggressively.
"If you let inflammation go, inflammation leads to scarring and scarring leads to narrowing of the intestines, which becomes a surgical problem," says Prabhakar Swaroop, MD, assistant professor and director of the Inflammatory Bowel Disease Program at the University of Texas Southwestern Medical Center in Dallas. "You want to treat the person aggressively to prevent these problems."
"In addition to improving symptoms, the anti-TNF modifiers are associated with mucosal healing," says Bloomfeld. "We hope that in healing the mucosa we can stop the progression of the disease and prevent complications of Crohn's that result in hospitalization and surgery."
While there are other treatments that suppress the immune system to treat Crohn's, they too have side effects, says Bloomfeld. Like the biologics, drugs that suppress the immune system increase the risk of lymphomas and infections, which can be severe.
Cortiosteroids like prednisone, for example, can cause a wide range of adverse effects including weight gain, mood swings, bone loss, skin bruising, high blood pressure, and high blood sugar. Those side effects are why corticosteroids may be used to control a flare, but aren't the choice to treat Crohn's over a long period of time. "The stop-gap method, which is steroids, is something we cannot use long term," says Swaroop.
Biologics: Weighing the Risks and Benefits
When prescribing any drug, doctors look at the potential risks against the benefits they hope or expect to achieve. Although doctors don't all share the same philosophy on when to start biologics for Crohn's disease, they do agree that biologics should be used when people have severe disease that can lead to permanent damage and make surgery unavoidable.
Swaroop says he looks for signs that the disease is progressing, such as how long between a person's diagnosis of Crohn's and when they have fistulas. "These are the patients who generally do better on biologics, who have the quality of life improvement, who are able to avoid surgery and get back in the workforce," he says.
Before prescribing biologics, doctors check for potential problems. "In the beginning, of course, we go ahead and make sure the person does not have an active liver infection or TB," says Marie Borum, MD, professor of medicine and director of the Division of Gastroenterology and Liver Diseases at George Washington University in Washington, D.C.
Once someone starts a biologic, the doctor looks for side effects in order to find them before they become serious. Monitoring includes include lab tests and possibly regular skin checks for signs of skin cancer.
Risks and Rewards of Crohn's Treatment: The Bottom Line
All effective therapies for Crohn's disease come with some risk, says Bloomfeld. "It is not an option not to treat Crohn's, so we certainly need to weigh these risks against the benefits of having the disease well treated."
"It may be challenging for the individual to consider all of these risk and benefits. They need to work with their gastroenterologist to decide what might be most beneficial for them and what risk they are willing to accept to effectively treat Crohn's disease," Bloomfeld says. "You have to be willing to accept some risk to adequately treat Crohn's disease."