Reviewed by: HU Medical Review Board | Last reviewed: May 2022 | Last updated: July 2022

Belimumab (Benlysta®) is a biologic drug approved by the U.S. Food and Drug Administration (FDA) for adults and children with lupus and lupus nephritis (kidney disease caused by lupus).1-3

Biologic means that a drug is created from a living organism using biotechnology. Biologics change how a certain body process works, altering cell actions or reactions. Belimumab changes the way a certain white blood cell works in the body of people with lupus and lupus nephritis.1-3

Belimumab is approved for people age 5 and older with active, autoantibody-positive lupus who are receiving standard therapy. It is also approved for people age 5 and older with active lupus nephritis who receive standard therapy.1-3

The benefits of belimumab have not been studied in people with severe active central nervous system lupus. It also has not been studied in combination with other biologics.1

What are the ingredients in belimumab (Benlysta)?

The active ingredient is belimumab.1

How does belimumab (Benlysta) work?

Belimumab is a human IgG1λ monoclonal antibody that targets soluble human B lymphocyte stimulator proteins (BLyS, or BAFF and TNFSF13B).1

B cells are a type of white blood cell that recognize and fight germs. When a B cell finds what it thinks is a virus, bacteria, or other germs, it attacks and latches onto that foreign invader to kill it. In an autoimmune disease like lupus, these B cells mistake healthy cells for invaders.1

Belimumab does not bind to B cells directly. But it binds to BLyS, a B-cell survivor factor, which limits the survival of reactive B cells, including those that attack healthy tissue. This helps reduce the inflammation caused by lupus.1

Benlysta side effects

Possible side effects of belimumab include:1

  • Nausea
  • Diarrhea
  • Fever
  • Stuffy or runny nose
  • Cough
  • Trouble sleeping
  • Headaches
  • Pain or allergic reaction at the injection site

More serious side effects that sometimes occur include:1

These are not all the possible side effects of Benlysta. Talk to your doctor about what to expect or if you experience any changes that worry you.

Other things to know

Both the intravenous (IV) version and the subcutaneous (under the skin) injection version are approved for use in people with lupus who are age 5 and older.1

People who have severe and active central nervous system involvement should not take belimumab. You also should not take it if you are currently taking another biologic drug.1

Women who wish to get pregnant should not try to conceive for at least 4 months after their last treatment.1

It is not yet known whether belimumab causes birth defects or miscarriage in pregnant women. Scientists do know that it crosses the placenta, especially in the third trimester, and impacts the immune system of fetuses and babies born to monkeys. Researchers also do not know how belimumab impacts babies fed breast milk by mothers taking the drug.1

Before beginning treatment for belimumab, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.

For more information, read the full prescribing information of belimumab (Benlysta).

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