Erelzi (etanercept) is a biologic medicine that helps the pain and swelling of arthritis. It works by blocking TNF (Tumor Necrosis Factor), a type of signalling protein (called a cytokine), that is involved in systemic inflammation. Erelzi belongs to a class of similar medications called Anti-TNF agents.
Erelzi is a type of medicine that is called a biosimilar. A biosimilar is a newer type of biologic medication that is designed to be identical to an existing biologic medication, but is created using a different process. Erelzi is a biosimilar of Enbrel. Both medications are known by the same generic name: etanercept. Biosimilars are often more cost effective than the medications that they replicate.
Erelzi is available as a subcutaneous (under the skin) injection that is usually taken once a week. It is sometimes prescribed for twice a week.
Important Tests and Risks
Erelzi can make it a bit harder for people to fight off infections. People taking this medicine should call their doctor if they have a fever, think they have an infection, or have been prescribed antibiotics to treat an infection.
Patients should coordinate with their doctor to stop treatment before any surgery. It can be re-started once things have healed and there’s no sign of infection.
Patients should discuss all vaccinations with their doctor because some are not advisable to get while taking Erelzi.
It is important to get a TB (tuberculosis) skin test and a chest x-ray before starting Erelzi.
Drug Identification Number (DIN): 02455323, 02455331
How Erelzi Works
In some people with arthritis, a signalling protein (cytokine) called Tumour Necrosis Factor (TNF) is present in the blood and joints in excessive amounts where it increases inflammation (pain and swelling).
Erelzi (etanercept) is another type of protein called a fusion protein that was developed by scientists to block TNF. It is built out of other proteins that are found in the human body including part of an antibody that can normally found in the blood, and a receptor called TNF receptor 2 that binds to TNF.
When Erelzi binds to TNF, it blocks it from working. This makes it part of a family of arthritis medicines called TNF Blockers. In blocking TNF, Erelzi suppresses the body’s immune system.
Though this suppression can make it slightly harder for patients to fight off infections, it also helps to stabilize an overactive immune system.
In patients with arthritis, this medicine can:
- Reduce the pain and swelling (inflammation) in arthritic joints
- Improve day to day function
- Prevent long-term damage caused by joint inflammation
Side Effects of Erelzi
Patients should talk to their doctor if they are concerned about any side effects.
All fevers and infections should be reported to a doctor.
MORE COMMON side-effects include:
- Mild skin reaction at the injection site (itchiness, redness, and mild swelling)
- Upper respiratory tract infections (such as sinusitis)
RARE side-effects include:
- Blood Counts – Erelzi can cause a drop in the numbers of white blood cells (which are needed to fight infection) or red blood cells (which carry oxygen). This is very rare and it is unusual for this to be a serious problem. Patients should get occasional blood tests so their doctor can monitor their liver and blood counts.
- Infection – There is an increased risk of serious infection. Any infections or fevers should be taken seriously and reviewed by a doctor
- Nervous System – There have been rare reports of some patients developing disorders that affect the nervous system (multiple sclerosis, seizures, or inflammation of the nerves of the eye) while taking Erelzi. Fortunately, these reports are exceedingly rare.
- Heart – Patients should inform their doctor if they have congestive heart failure as Erelzi may make it worse.
- Malignancy – When used for long periods of time, Erelzi may be associated with a small increased risk of lymphoma (cancer)
How to minimize the side-effects of Erelzi:
- Erelzi should be taken as prescribed by a doctor
Erelzi should not be taken with other medications that also block TNF.
Who Should NOT Take Erelzi
Patients who should NOT be taking Erelzi (etanercept) include:
- Patients who have had a previous serious allergic reaction to Erelzi (etanercept)
- Patients taking other biologic medications or Xeljanz
- Possibly patients who have cancer or have had a past history of certain cancers
- Patients who have severe or uncontrolled congestive heart failure
- Patients who have multiple sclerosis
- Patients with active infections (such as tuberculosis)
Anyone who becomes pregnant while taking Erelzi should notify their doctor.
When to Call a Doctor
People taking Erelzi should call their doctor if they feel sick and want to stop, or if they are concerned about any side effects.
Other reasons for people taking Erelzi to call a doctor include:
- Fever, infection, or suspected infection
- If another doctor has prescribed antibiotics to fight an infection
- Upcoming surgery
- Planning to get a vaccination – not all vaccinations are safe with Erelzi
- Development of a rash
Watch Dr. Andy Thompson, a Canadian rheumatologist, introduce Erelzi.