Crohn’s disease biologics are medications created using components of living organisms. By targeting specific parts of the body’s inflammatory process, these medications can help improve all kinds of symptoms of CD.

Crohn’s disease (CD), along with ulcerative colitis, is one of the primary types of inflammatory bowel disease (IBD). While various medications can help treat this condition, biologic therapies are a rising area of interest.

This article answers common questions about biologics for Crohn’s disease.

Biologic therapies use components of living organisms. These medications may contain substances such as enzymes, DNA, or proteins from plant and animal sources.

In CD, biologics work by interrupting specific moments in the body’s inflammatory process. Each class of biologic therapy has a unique mechanism.

Current biologic therapies for CD include:

  • Anti-TNF agents: These that work to counteract the inflammatory cytokine known as tumor necrosis factor (TNF). The names of these drugs are:
    • infliximab (Remicade)
    • adalimumab (Humira)
    • etanercept, (Enbrel)
    • golimumab (Simponi)
    • certolizumab pegol (Cimzia)
  • Anti-integrin agents: These drugs inhibit the movement of immune cells to inflamed areas in the intestines. These are vedolizumab (Entyvio) and natalizumab (Tysabri).
  • Interleukin inhibitors: Medications that prevent the activity of interleukin cytokines, which are responsible for stimulating inflammatory reactions. Ustekinumab (Stelara) is an interleukin inhibitor for CD.
  • Janus kinase (JAK) inhibitors: These inhibit the activity of JAKs, which are enzymes that initiate inflammatory processes. A JAK inhibitor for CD is upadacitinib (Rinvoq).

The success of biologics in CD is difficult to quantify because experiences of CD symptoms and severity vary greatly. What works for one person may not work for another, and vice versa, and success rates can vary depending on the criteria under evaluation.

Overall, 2022 research suggests that anti-TNF agents have the greatest success rate of available biologics for CD for both gastrointestinal (GI) symptoms and extraintestinal manifestations (symptoms occurring outside of the GI system).

A systematic review and meta-analysis from 2021 found that after 1 year of therapy with anti-TNF agents, nearly 49% of people with CD experienced remission, a reduction in signs and symptoms of disease.

Even though biologic therapies for CD can start affecting inflammation within days, depending on the medication, it can take 2 weeks or longer to notice symptom improvement in IBD conditions.

All medication takes time to work because healing in the body is a process — not instantaneous. As inflammation subsides from biologic intervention, the body gradually returns to a balanced state of function.

Any product approved by the Food and Drug Administration (FDA) for use in the general public has passed rigorous clinical safety trials. However, biologics can still cause side effects and may not be suitable for everyone.

Common side effects include:

  • injection site reactions
  • rash
  • chest discomfort
  • fever
  • headaches
  • chills
  • dizziness
  • skin flushing
  • coughing
  • blood pressure spikes
  • nausea
  • frequent infections

One small, single-center prospective case series study from 2021 found more than half of people taking biologics for IBD (for CD or ulcerative colitis) experienced adverse drug-related side effects, though only 2% of those reactions were severe.

Biologics may not be appropriate for people who are pregnant or living with certain co-existing conditions, like liver failure.

Are biologics worth the risk?

Determining if biologics are worth the risk of side effects or complications is a very individual decision. A person’s symptoms, CD severity, overall health, preferences, and response to other therapies are all considered.

For people who have not seen success on first-line treatments for CD, adding a biologic may significantly improve symptoms that otherwise cause major distress in daily life. However, for people who have other options available with a lower risk for side effects, biologics may not be the next step.

A person does not have to take biologics forever, but doing so may help CD outcomes.

There is no cure for Crohn’s disease, but biologic therapies can help achieve a state of remission for extended periods. If remission occurs, it is possible to stop taking a biologic. However, doing so may increase the risk of CD returning sooner.

According to a retrospective study from 2023, people remaining on biologic therapy in IBD had significantly fewer relapses at the 1- and 3-year marks compared with people who stopped biologic therapy completely.

Speaking with a doctor about biologics for CD is the first step toward adding these therapies to a treatment plan. Not everyone is a candidate for biologic use, and different biologics may be more effective depending on the severity and presentation of CD symptoms.

To help kick-start a conversation about biologics and make the most out of an appointment, a person can consider:

  • learning as much as possible about biologics and their uses
  • attending the appointment with a list of questions about biologic use
  • asking why or why not biologics might be the next step
  • bringing a loved one to listen in and add perspective after the visit
  • taking notes to review in-depth at home

For people who may benefit from biologics in CD, doctors will explain the frequency of the medication, what to expect, symptoms to watch for, and any lifestyle changes that will help support CD treatment.

Biologics are one of the options in the treatment of Crohn’s disease, especially for non-GI symptoms.

These medications work by interrupting the body’s inflammatory process. As with any medication, there are risks to weigh, and biologics may not work for everyone in every case. A person can talk with their doctor about what might be best for their specific situation.