Key takeaways

  • Monoclonal antibodies are a type of biologic medication that can treat moderate to severe inflammatory bowel disease (IBD) by targeting specific inflammatory processes in your body.
  • Your doctor might recommend this advanced type of treatment if other therapies for conditions like Crohn’s disease or ulcerative colitis have not worked for you or have caused unmanageable side effects.
  • You might receive monoclonal antibodies as intravenous (IV) infusions in a clinical setting or as subcutaneous injections that you perform at home. The right method for you will depend on the specific medication and your individual needs.

Inflammatory bowel disease (IBD) is a category of autoimmune conditions that cause inflammation of your gastrointestinal tract. The two forms of IBD are Crohn’s disease and ulcerative colitis (UC).

Treatment for IBD may involve anti-inflammatory medications, corticosteroids, immunomodulators, Janus kinase (JAK) inhibitors, or biologics. Monoclonal antibodies are one type of biologic drug that can be used to treat IBD.

In this article, we discuss what monoclonal antibodies are, how they work to treat IBD, and what side effects they may cause.

Biologic drugs are medications made in a lab from organic cells. Monoclonal antibodies are a type of biologic designed to mimic the action of your body’s immune cells and target specific substances within your body.

Monoclonal antibodies are a revolutionary treatment for conditions such as cancer, infectious diseases, and autoimmune disorders, including IBD.

When used to treat IBD, monoclonal antibodies have been found to improve disease management, reduce the rate of hospitalization and surgery, and improve quality of life.

Biologics work by targeting specific molecules, cells, or proteins in your body to reach a desired outcome. To treat IBD, monoclonal antibodies work by targeting receptors and proteins that play a role in inflammatory processes, such as:

  • tumor necrosis factor-alpha (TNF-alpha)
  • integrins
  • interleukins

Not all monoclonal antibodies work in the same way. For example, infliximab and adalimumab are TNF-alpha blockers, whereas vedolizumab is an integrin blocker.

No single monoclonal antibody is right for all people with IBD. Your doctor will recommend a medication based on a range of factors, including:

  • whether you have Crohn’s disease or UC
  • the severity of your disease
  • your medical history
  • your risk of complications
  • the drug’s cost

Monoclonal antibody drugs that may be used to treat IBD include:

  • infliximab
  • adalimumab
  • golimumab
  • vedolizumab
  • certolizumab pegol

Doctors may prescribe monoclonal antibodies if you have moderate to severe Crohn’s disease or UC that does not respond to other treatments.

You might also be a candidate if you cannot tolerate conventional treatments or if you have any health conditions or other factors that prevent you from taking other types of medication for IBD.

To maximize the benefit of monoclonal antibodies, doctors typically prescribe them in a continuous maintenance dosage rather than as needed.

Doctors may also perform therapeutic drug monitoring to track the concentration of the drug in your blood. This allows them to optimize the dosage based on your individual characteristics and response.

Monoclonal antibodies may be given via intravenous (IV) infusion or subcutaneous injection. The method of delivery depends on the type of drug and your specific condition.

IV infusions typically take place in a clinical setting. During an infusion, healthcare professionals deliver medications into your vein slowly over time.

The duration of an infusion varies based on the medication in question. For example, an infusion of the monoclonal antibody infliximab generally lasts at least 2 hours.

A subcutaneous injection is an injection under your skin.

Certain drugs can be given as either infusions or injections, whereas others are available only as injections. For example, you can give yourself doses of adalimumab at home using either a prefilled syringe or an injection pen.

When taking monoclonal antibodies for IBD, you may experience some side effects.

The specific side effects will depend on the drug, but possible effects include:

  • infusion-related reactions, such as fever and itching
  • injection site reactions, such as skin irritation
  • respiratory infections
  • headaches
  • nausea

Other reactions that researchers have observed include:

  • skin and subcutaneous tissue disorders
  • infections
  • musculoskeletal disorders
  • blood disorders
  • gastrointestinal disorders
  • vascular (blood vessel-related) disorders

If you have moderate to severe IBD, such as Crohn’s disease or UC, your doctor may recommend taking a type of medication called a monoclonal antibody.

This type of medication may be right for you if your IBD has not responded to conventional therapies. Monoclonal antibodies are a type of biologic drug, meaning they’re made using living cells.

They’re typically given as either an IV infusion or an injection under your skin.