Biologics for IBD 

What is a biologic medicine and how does it work?

Biologic medicines are antibodies (immunoglobulins) that are created in a laboratory through biological rather than chemical processes. Antibodies are produced naturally by white blood cells of the immune system to target and destroy specific bacteria or viruses. The antibodies that we call biologics target the proteins in the inflammatory pathways rather than the bacteria or viruses that cause an infection. They are manufactured in living cells which create specific antibodies that pinpoint and remove specific inflammatory proteins. This switches off the inflammatory pathway and allows the inflammation to settle down. For more information about inflammation, see our Medication for inflammation page. Biologics are big proteins, so they have to be given by injection and can’t be taken as an oral medication. Biologics have been used for over 20 years to treat Crohn’s disease, ulcerative colitis and other conditions such as rheumatoid arthritis.

Biologic medicines are effective in improving symptoms, helping people feel better, and reducing the need for hospital visits or surgery. They can also help people get into or maintain remission. There are many different biologic medicines, and they each work in their own way targeting different inflammatory pathways:

Anti-tumour necrosis factor agents (anti-TNF): these medicines block a protein called tumour necrosis factor alpha (TNF-alpha). TNF-alpha helps you fight infections but can also promote inflammation in the intestines and other organs. Anti-TNF medications can reduce symptoms of IBD and help heal the intestines. Examples of anti-TNF biologics include adalimumab, infliximab, and golimumab.

Interleukin-12 and -23 antagonists: these biologics stick to a molecule called interleukin (IL)-12 and IL-23. Your immune system naturally makes IL-12 and IL-23 to help fight infections. However, overactive IL-12 and IL-23 can cause ongoing inflammation. An example medication from this class is ustekinumab.

Integrin receptor antagonists: these biologics target proteins in the blood vessels in the bowel wall called integrins. By blocking integrins, these medicines stop inflammatory white blood cells migrating into the bowel wall. This reduces bowel inflammation and improves symptoms. An example of this type of biologic is vedolizumab.

You can find more information about each medicine on our Medication for IBD page.

There are also biosimilar medications: these have an identical protein structure to the corresponding biologic. You can learn more about biosimilars on our Biosimilars for IBD page.

How do I access biologics for my IBD?

Biologic medicines are regulated as prescription medicines in Australia. This means you need to get a prescription from your doctor or specialist. You will also need to have some tests before you can take them.

Why have I been prescribed a biologic for IBD?

You have likely been prescribed a biologic because you have moderate to severe Crohn’s disease or ulcerative colitis. Doctors often prescribe biologics when other IBD medicines haven’t worked well, have stopped working, or caused side effects.

Starting a biologic can feel like a big step. It’s normal to feel worried about how it might affect your body and daily life. It’s important to talk to your IBD team about how you’re feeling. You can also call our nurseline and helpline for support.

How do I take biologic medications?

You can’t take biologics by mouth because the gut breaks them down before they can work effectively. The way you take the medication depends on which one you are on. There are two ways to take biologics:

• Intravenously (IV): this means the medicine is given directly into the vein through a drip in your arm. A nurse or doctor will do this in a hospital or clinic. It can take 30 minutes to a few hours, and you will be monitored for any allergic reactions or symptoms like headaches or rashes.
• Subcutaneously: this means the medicine is injected under your skin. You can usually do it yourself at home with a prefilled pen or syringe device. Your IBD team will help you with this and ensure you have everything you need, like a sharps container to dispose of the used device. Additional resources such as video tutorials may be available to guide you. If you’re nervous about doing it yourself, your doctor or nurse might do the injection for you.

You might have all your doses as infusions, all as injections, or start with infusions then switch to injections. How often you take the medicine depends on your treatment plan and needs, and your IBD team will adjust it based on how well it works for you.

How fast do biologics work?

It can take a few weeks or even months to see improvement in symptoms after starting a biologic medicine, but some people feel better sooner. If you don’t see any improvement after a few months, your IBD team may suggest stopping that medication and trying a different one.  

How long will I be on biologics?

How long you stay on a biologic medicine depends on how you feel, medical test results, and discussions with your IBD team. If the medicine works well for you, you might take it for a long time.

For some people, the medication might stop working as effectively over time. This can happen because the immune system gets used to it or makes antibodies that reduce its effectiveness. If that happens, your doctor might increase your dose, switch you to a different biologic, or prescribe other medicines to help.

How much do biologic medications cost?

Biologic medicines are expensive and subject to strict governmental restrictions and regulations to be subsidised on the Pharmaceutical Benefits Scheme (PBS). To keep getting your biologic medicine, you’ll need to have your IBD assessed every 6 months. This might include regular blood tests and appointments with your IBD team. If you qualify, the government will cover almost all the costs of the medication which can be thousands of dollars a year.

Are biologics safe and what are the possible side effects?

Before you start a biologic medicine, your IBD team will check if it’s right for you. This might include blood tests, making sure your vaccinations are up to date, and other scans. Most people find that the benefits of biologics are greater than the possible side effects, but it’s important to know what the risks are. Some side effects can include:

• Headaches, fever, and chills.
• Higher risk of infections, since biologics target your immune system. You should stay on top of vaccinations to prevent this.  If you do develop high fevers or chills, you should seek medical advice urgently.
• Abnormal blood tests including liver function.  Blood tests need to be taken on a regular basis as advised by your IBD team.
• Cancer risk. Anti-TNF medications are associated with a very slight increase in the risk of lymphoma, which is a cancer of the lymphatic system. The risk is very low but higher in patients using an anti-TNF medication in combination with an immunosuppressant such as azathioprine.  
• Lupus-like reaction. In rare cases, anti-TNF medications can cause a lupus-like reaction presenting as a rash, joint pain, muscle aches, or fever.
• Skin reactions like rashes, redness, itching, bruising, pain, or swelling at the injection site. In rare cases, psoriasis (a skin condition) can develop.

Most people don’t get side effects. You can discuss the risks of side effects with your IBD team. Always notify your IBD team if you have any of these side effects.

Do biologics impact fertility, pregnancy, and breastfeeding?

In general, biologics are considered safe to continue throughout pregnancy and during breastfeeding and do not reduce fertility.

If you are planning to have a family, please let your IBD Team know – the advice is almost always to continue the biologic throughout pregnancy. If you fall pregnant, please do not stop the biologic without talking to your IBD specialist as soon as possible.

You can find more information on the safety of each biologic on our Medication for IBD page and our Fertility, Pregnancy and IBD page. This area of research is rapidly developing, so it’s important to talk to your IBD team about your options.

This information has been designed to provide general information about biologics. It is not intended to replace specific advice from your doctor or any other health professional. Please speak to your pharmacist, doctor, or IBD nurse for further information. This page has been reviewed by Prof Paul Pavli, A/Prof Greg Moore, and Dr Emma Flanagan.