Brenzys (etanercept) is a biologic medicine that helps the pain and swelling of arthritis. It is used in the treatment of Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis, and other types of arthritis.

Brenzys works by blocking a signalling protein (or cytokine) called Tumor Necrosis Factor (TNF) that is involved in systemic inflammation. Brenzys belongs to a class of similar medications called Anti-Tumor Necrosis Factor agents.


Brenzys is a type of medicine that is called a biosimilar. A biosimilar is a type of biologic medication that is designed to be identical to an existing biologic medication, but is created using a different process.

Brenzys is a biosimilar of Enbrel. Both medications are known by the same generic name: etanercept. Biosimilars are often cheaper than the original medication.

Taking Brenzys

Brenzys is available as a subcutaneous (under the skin) injection that can be taken at home.

Administration, Dose, and Frequency

Brenzys is usually taken once a week. It is sometimes prescribed as twice a week. The standard dose is 50 mg once a week.

Subcutaneous injections (under the skin injections) are easy to do compared to other types of injections. A small needle pokes just under the skin to deliver medicine into the “fatty tissue” below.

Learn how take Brenzys at home:

The manufacturer of Brenzys offers a support program to Canadian patients that are prescribed the medication:

Important Tests and Risks

Risk of Infection

Brenzys 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. Most patients stop the medication a week or two before surgery. It can be restarted 10-14 days after the surgery as long as there is no sign of infection.

Patients should discuss all vaccinations with their doctor because some (live vaccines) are not advisable to get while taking Brenzys.

Tuberculosis (TB) Test

It is important to get a TB (tuberculosis) skin test and a chest x-ray before starting Brenzys.


How Brenzys Works

In some people with arthritis, a signalling protein (cytokine) called Tumor Necrosis Factor (TNF) is present in the blood and joints in excessive amounts where it increases inflammation (pain and swelling).

Brenzys (etanercept) is another type of protein called a fusion protein that was developed by scientists to block Tumor Necrosis Factor. 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 Tumor Necrosis Factor receptor 2 that binds to Tumor Necrosis Factor.

When Brenzys binds to Tumor Necrosis Factor, it blocks it from working. This makes it part of a family of arthritis medicines called Tumor Necrosis Factor Blockers. In blocking Tumor Necrosis Factor, Brenzys 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

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)
  • Headaches
  • Upper respiratory tract infections (such as sinusitis)

RARE side-effects include:

  • Blood Counts – Brenzys 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 Brenzys. Fortunately, these reports are exceedingly rare.
  • Heart – Patients should inform their doctor if they have congestive heart failure as Brenzys may make it worse.
  • Malignancy – When used for long periods of time, Brenzys may be associated with a small increased risk of cancer, however, the data is not entirely clear.

How to minimize the side-effects of Brenzys:

  • Brenzys should be taken as prescribed by a doctor

Who Should NOT Take Brenzys

Patients who should NOT be taking Brenzys (etanercept) include:

  • Patients who have had a previous serious allergic reaction to Brenzys (etanercept)
  • Patients taking other biologic medications or JAK inhibitors
  • 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)

When to Call a Doctor

People taking Brenzys 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 Brenzys 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 Brenzys
  • Development of a rash

Anyone who becomes pregnant while taking Brenzys (etanercept) should notify their doctor.


Watch Dr. Andy Thompson, a Canadian rheumatologist, introduce etanercept (Brenzys / Enbrel):

Drug Identification Number (DIN)

02455323, 02455331