Non-TNFi Biologics (Abatacept, Rituximab, Tocilizumab)

Non-TNFi biologics are a class of biologics that target the immune system in different ways from TNFi medications. They interact with different kinds of white blood cells, such as T-cells or B-cells, in your immune system. They can also block chemicals called cytokines that cause inflammation.

White blood cells and cytokines are made by your immune system to fight off infection, however, in inflammatory arthritis (or autoimmune arthritis), they may be out of control and lead to inflammation. Non-TNFi biologics can suppress your immune system, ease inflammation, slow or stop disease progression and ease your symptoms.

Your rheumatologist may prescribe a biologic if your previous DMARD therapy was ineffective or if you cannot take conventional synthetic DMARDs. Personal considerations such as comorbidities and side effects may make Non-TNFi therapy (often with the addition of methotrexate) the best option.

For individuals with specific types of inflammatory (or autoimmune) arthritis, Non-TNFi biologics could be an addition to your DMARD monotherapy or double therapy or used alone. Your rheumatologist will determine which option is best for you based on your personal medical history and current Pharmaceutical Benefits Scheme (PBS) regulations.

Common Non-TNFi Biologics

• Abatacept (Orencia®, Orencia Clickject®)
• Tocilizumab (Actemra®)
• Rituximab (MabThera®, Riximyo®, Truxima®)

Some biologics are now available in Australia both from their original brand and from biosimilar brands. They must all meet the same standards of safety and efficacy.

Abatacept

Abatacept works by blocking signalling to a special kind of white blood cell called a T-cell. T-cells play a key role in your immune system and are probably important players in inflammatory arthritis. In these conditions, your immune system confuses some of your own cells as foreign invaders.

Your body activates T-cells by mistake to attack what it thinks is an outsider causing disease in your body. Activated T-cells send signals to the other inflammatory cells of your immune system. They “wake them” and call them into action. These other inflammatory cells send out signals of their own and may be linked to inflammation.

Abatacept is currently available in Australia for rheumatoid arthritis, psoriatic arthritis and polyarticular juvenile idiopathic arthritis through the PBS, providing patients meet the requirements. It can be given by IV infusion in a hospital or infusion centre or injected subcutaneously.

The infusion dose for rheumatoid arthritis is determined by factors such as your weight. Each dose takes around 30 minutes to administer and the total appointment time is normally around one hour. Abatacept infusions are administered at zero, two and four weeks and then every four weeks after that.

You (or someone you trust) can administer your subcutaneous injections at home each week. The standard injection dose is 125 mg.

Tocilizumab

Tocilizumab works by blocking a cytokine known as interleukin-6 (IL-6) that is found in abundance in the synovial fluid of people with some forms of autoimmune arthritis. The level of IL-6 often corresponds with the level of disease activity and joint damage. IL-6 is also believed to be a key player in many aspects of autoimmune function.

Tocilizumab is available in Australia for rheumatoid arthritis, giant cell arteritis and polyarticular juvenile idiopathic arthritis through the PBS, providing patients meet the requirements. It can be given by IV infusion or injected subcutaneously.

The infusion dose for rheumatoid arthritis is determined by body weight (normally 8 mg/kg). Infusions normally last for one hour and are given every four weeks in a hospital or infusion centre.

The tocilizumab pre-filled syringes come in a fixed dose of 162 mg, injected weekly on the same day.

Rituximab

Rituximab works by blocking a special kind of white blood cells known as B-cells. B-cells normally produce antibodies that help the body fight infection, however, in some forms of autoimmune arthritis, some B-cells produce harmful autoantibodies which lead to inflammation in the joints. Rituximab works by targeting and removing harmful B-cells. While it initially also removes some of the normal B-cells, they return after several months.

Rituximab is available in Australia for rheumatoid arthritis through the PBS, providing patients meet the requirements.

It is given as an IV infusion in a hospital or infusion centre. A course of treatment consists of two doses of 1,000 mg given two weeks apart. Normally, the treatment course is repeated every six months with monitoring blood tests done around three months after the last infusion.

What Are the Possible Side Effects of Non-TNFi Biologics?

Some of the common side effects of non-TNFi biologics include:

• Mild upper respiratory infections
• Headaches, sore throat, runny nose and similar symptoms
• Stomach and bowel discomfort
• Urinary infections

The injection or infusion itself may cause a skin rash or bruise at the injection site, a drop in blood pressure or shortness of breath.

Each medication has its own possible side effects. Most of these are minor and manageable, however, seek medical attention if you have any symptoms that concern you.

All biologics and other DMARDs affect the immune system and can increase your risk of both minor and serious infections. It is important to discuss these risks (and how to manage them) with your treating doctor.

 

Arthritis treatment information is also included in all editions of the CreakyJoints Australia Raising the Voice of Patients series. Learn more or download your free copy of A Patient’s Guide to Living with Rheumatoid Arthritis in Australia or A Patient’s Guide to Living with Axial Spondyloarthritis in Australia today.

For more information about biosimilars, the Therapeutic Goods Administration (TGA), Pharmaceutical Benefits Scheme (PBS) and much more, listen to the relevant episodes of our Patient PrepRheum podcast series or read the transcriptions attached to each episode.