TNF Antagonist Biologics

What are TNF Antagonists?

• TNF Antagonists are a type of biologic medication. Biologics are a newer class of DMARD (Disease Modifying Anti-Rheumatic Drug) & have been available for over 10 years now.

• Biologics are most commonly used in the treatment of inflammatory arthritis including rheumatoid arthritis, psoriatic arthritis & ankylosing spondylitis. However, they have also been used to try to treat a variety of other autoimmune rheumatic conditions.

What is the typical dose for a TNF antagonist? 

• While more biologics continue to become available and even more in development, there are currently 5 TNF antagonists which are most commonly used.

• Adalumimab (Humira) – It is given as a 40mg injection under the skin every second week

• Adalumimab (Amgevita) – A biosimilar to originator Humira, it is given as a 40mg injection under the skin every second week

• Adalumimab (Hadlima) – A biosimilar to originator Humira, it is given as a 40mg injection under the skin every second week

• Adalumimab (Idacio) – A biosimilar to originator Humira, it is given as a 40mg injection under the skin every second week

• Adalumimab (Hyrimoz) – A biosimilar to originator Humira, it is given as a 40mg injection under the skin every second week

• Adalumimab (Hulio) – A biosimilar to originator Humira, it is given as a 40mg injection under the skin every second week

• Certolizumab (Cimzia) – It is given as a 200mg injection under the skin on average every second week

• Etanercept (Enbrel) – It is given as a 50mg injection under the skin once per week

• Etanercept (Erelzi) – A biosimilar to the originator Enbrel, it is also given as a 50mg injection under the skin once per week

• Etanercept (Brenzys) – A biosimilar to the originator Enbrel, it is also given as a 50mg injection under the skin once per week

• Golimumab (Simponi) – It is given as 50mg injection under the skin one per month or as an intravenous treatment on average every 8 weeks

• Infliximab (Remicade) – It is given as an intravenous treatment on average every 8 weeks

• Infliximab (Avsola) – A biosimilar to the originator Remicade, it is also given as an intravenous treatment on average every 8 weeks

• Infliximab (Inflectra) – A biosimilar to the originator Remicade, it is also given as an intravenous treatment on average every 8 weeks

• Infliximab (Renflixis) – A biosimilar to the originator Remicade, it is also given as an intravenous treatment on average every 8 weeks

How do TNF antagonists work?

•  TNF, or tumour necrosis factor (named as it was discovered in cancer research but is a normal part of the immune system) is a specific molecule which helps drive inflammatory arthritis. By blocking TNF, we can modulate the immune system’s response which decreases inflammation, reduces pain, and improves function.

How soon will I feel the effect of TNF antagonists?

• It usually can take a few weeks to start to work. We look for improvement by 3 months.

Which TNF antagonists works the best?  Which are safest?

• Research so far has not reliably found a significant difference between the different TNF antagonists. They appear to work equally as well and are on the whole equally safe. For any particular patient, it is possible that one may work better or be safer than another, but it is not predictable. Please see below for potential side effects.

If I start a TNF antagonists, can I stop all my other DMARDs?

• Most rheumatologists will suggest you continue with at least methotrexate, assuming you have not had side effects, in addition to a TNF antagonist. Studies have shown the TNF antagonists work significantly better when combined with methotrexate.

• Keep in mind: In most instances, your rheumatologist has recommended you start a TNF antagonist because your inflammatory arthritis has not been well controlled. It is important to try to control your disease as best as possible first, which may mean continuing all DMARDs for some time, before trying to decrease them.

What are the possible side effects of TNF antagonists?  How can I reduce the chance of having a side effect?

1. Local Injection Reactions (red, painful or itchy skin): Rotate the area where you inject. 

2. Intravenous Infusion Reactions: If severe, the medication is stopped. However, certain medications can be given to prevent similar reactions from re-occurring

3. TNF Blockers can increase your risk of developing severe infections.  Stop your TNF Blockers any time you have a fever. It is usually safe to resume it once you are better. Fevers and other severe illness should not be ignored and discussed with your doctor.

4. TNF Blockers can increase your risk of developing or reactivating Tuberculosis. Prior to starting a TNF Blockers, your rheumatologist will ask you to do a TB skin test and get a chest x-ray to look for signs of previous TB exposure. If positive for previous TB exposure, you may require anti-TB medications before safely starting a TNF Blockers. 

5. Exacerbate Congestive Heart Failure.  TNF Blockers should be avoided in most patients with heart failure.

6. Rarely, TNF Blockers may cause the development of nervous system problems, such as multiple sclerosis.  Let your doctor know if you or an immediate family member already have a known nervous system problem

7. TNF Blockers may cause a small increased risk for certain types of cancer.  Fortunately this is rare and in fact, the association is not entirely clear.

8. Let your doctor know if you are undergoing or have undergone treatment for cancer, particularly lymphoma

9. Viral Hepatitis:  There may be some risks associated with taking TNF Blockers and certain types of hepatitis. Let your doctor know if you have ever been diagnosed with hepatitis.

10. Medication Interactions: Live vaccines should be avoided while on a Biologic.  Discuss vaccinations with your rheumatologist.  Live vaccines should be given prior to starting a TNF antagonists.

What should I do if I miss a dose?

• If you miss your dose, you can take it as soon as your remember safely. Then, resume your normal routine. As long as this does not happen regularly, you will likely not feel any ill effects.

How can I safely stop TNF antagonists?

• It is safe to just stop all TNF antagonists; you do not need to slowly reduce the dose. However, keep in mind, if you were gaining any benefit, it will usually take a few weeks to lose it.