Doctor Q&A: How Do Biologics Treat Crohn's Disease?


Biologics are a viable treatment for people with Crohn’s disease, but there is still a lot of misinformation out there on how they work and what they do. Dr. Constance A. Pietrzak, a gastroenterologist at Advocate Medical Group in Chicago, explains what you should know.

What are biologics?

"Biologics," or biologic drugs, are medications that are made from things that are found in life and their products, mainly proteins. These medications are antibodies which bind to specific parts (proteins) of the immune response interfering with inflammation. One common target of multiple biologics used in inflammatory bowel disease (IBD) is tumor necrosis factor alpha (TNF-alpha).

How do they work to treat Crohn’s disease?

In Crohn's disease (CD), biologic treatments have a distinct advantage over other therapies. They block the immune response by acting on a specific target that is either lacking, not working, or in excess in patients with Crohn’s, rather than suppressing the whole immune system. Biologics can increase the anti-inflammatory response to slow down inflammation and improve the disease.

How are the different types of biologics administered?

All biologics are administered as a type of infusion or injection. Infusions are usually given at an infusion center and take 30 minutes, one hour, or two hours to infuse. They are given at specific time intervals, usually every four to eight weeks after an initial induction period, depending on the medication. Injections are administered under the skin and can be done at home. After an initial induction period, injections are typically given every two to four weeks, depending on the medication.

What are the common side effects?

One side effect specific to biologics is injection site reaction, such as redness, bruising, itching, swelling, pain, or ulceration at the injection site. Other potential side effects include infusion reactions (hives, swelling, difficulty breathing, low blood pressure), infections due to lowering of the immune system, cough, sore throat, fevers, nausea, and stomach ache. Other serious side effects include heart failure, life-threatening blood infections, tuberculosis, blood disorders, and vision changes. In rare cases lymphoma has been reported.

What is the difference between the biologics currently on the market? Is there a difference in their effectiveness?

The types of biologics currently in use for Crohn’s disease are as follows:

TNF-alpha blockers- These inhibit the immune response by blocking TNF-alpha.

Integrin receptor blockers- These work by blocking migration of inflammatory cells across blood vessels into areas of inflammation in the GI tract.

Every patient responds differently to each biologic agent and it is difficult to say which is more/most effective. When a patient responds well to one biologic, it is usually best to continue that drug for as long as the disease is well controlled. Studies comparing the biologics and their efficacy are limited.

Why do some biologics work for some people, but not others?

The reason some biologics work for some people and not others is because some individuals will make antibodies that bind to and work against the biologic drug, especially the TNF-alpha blockers. These are referred to as anti-drug antibodies (ADAb), and the formation of these antibodies can lead to allergic reactions to or loss/lack of efficacy of the biologic.

How do you know when a biologic is working?

The best way to know if a biologic is working is if symptoms are improving. The goal with these agents is to improve and eliminate symptoms and then keep patients symptom-free long term. It is important to let patients know that even if they are no longer having any symptoms, they need to continue taking their medication to prevent disease flares. If biologics are stopped, there is a good chance symptoms can recur.

How have biologics changed the treatment of Crohn’s?

Biologics have revolutionized the treatment of Crohn's disease. Patients with moderate to severe disease which did not respond to other types of available therapies— aminosalicylates (5-ASAs), corticosteroids, immunomodulators—can now be symptom-free with the use of biologics.

What biologics are being studied to treat Crohn’s in the future?

Despite the increasing number of available therapies for Crohn’s, biologics are still limited in efficacy, and safety concerns remain an issue. There remains a focus on developing new, more effective and safer medications to treat the disease. A number of new medications are being studied, including other TNF-alpha and interleukin-12 (IL-12) blockers, which play a major role in the inflammatory response.

Growth hormone and immune system stimulating agents are also being looked at as a possible treatment. Parasites are known to decrease the immune response and inflammation, and studies are being conducted on their efficacy in patients with Crohn’s. The use of probiotics and prebiotics, as well as fecal transplants, are being studied as well.

What else should Crohn’s patients know about biologics?

Biologics are extremely effective medications in treating Crohn’s. It is very important that you work with your doctor when taking these medications and keep them informed of any symptoms you experience, either related to your Crohn’s or potential side effects of the medications. Also, it is imperative that you do not stop these medications on your own. If you do, only restart them with the guidance of your doctor, and not on your own.