[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Other immunomodulating biologics](https://durgical.com/en/pharmacology/classes/other-immunomodulating-biologics/) › Belimumab

[Pharmacology](https://durgical.com/en/pharmacology/) · [Other immunomodulating biologics](https://durgical.com/en/pharmacology/classes/other-immunomodulating-biologics/)

# Belimumab

A human antibody against BLyS (BAFF), a B-cell survival factor, for systemic lupus erythematosus and lupus nephritis.

Updated 2026-11-01

- Class: [Other immunomodulating biologics](https://durgical.com/en/pharmacology/classes/other-immunomodulating-biologics/)
- Target: B-lymphocyte stimulator (BLyS, also called BAFF)
- ATC code: L04AG04

◆**B-lymphocyte stimulator (BLyS, also called BAFF)**Belimumab

ⓘ The figure shows BAFF (BLyS) bound to belimumab.

**Target in 3D:** B-lymphocyte stimulator (BLyS, also called BAFF). PDB structure 5Y9J (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/5Y9J) · Drag to rotate · pinch to zoom

## Mechanism of action

Belimumab is a human IgG1λ monoclonal antibody that binds soluble BLyS, a TNF-family cytokine that keeps B cells alive and helps autoreactive B cells mature. Without BLyS these B cells die by apoptosis, fewer become plasma cells and autoantibody production falls, which lowers lupus activity.

- Antibody binds soluble BLyS
- B cells lose a survival signal
- Fewer autoreactive plasma cells
- Autoantibodies and lupus activity fall

## Pharmacokinetics

**Absorption**
Intravenous infusion or subcutaneous injection

**Metabolism**
Broken down like other antibodies

## Indications

- Systemic lupus erythematosus, with standard therapy [Systemic lupus erythematosus →](https://durgical.com/en/conditions/systemic-lupus-erythematosus/)
- Lupus nephritis [Lupus nephritis →](https://durgical.com/en/conditions/lupus-nephritis/)

## Adverse effects

### Common

- Nausea, diarrhoea
- Headache or migraine
- Injection-site reactions
- Pain in the arms or legs; runny nose

### Serious (rare, important)

- Serious infections
- Depression, suicidal thoughts and behaviour
- Progressive multifocal leukoencephalopathy: memory loss, trouble thinking, speaking or walking, vision changes
- Infusion and hypersensitivity reactions, including anaphylaxis, which can appear up to a week after an infusion

## Contraindications

- Hypersensitivity to belimumab

## Key interactions

**Live vaccines**
Avoided around and during treatment; vaccines received in the past month are reported.

**Other immunosuppressants**
Added infection risk.

## What is monitored

- Mood, sleep and suicidal thoughts
- Signs of infection
- New neurological symptoms
- Reactions during and after each infusion

## Administration and safety

- Intravenous infusion over about an hour in a healthcare facility, or subcutaneous autoinjector or syringe.
- Premedication may be given; the person is watched during and after the infusion.

## Nursing care

- Ask about depression or thoughts of self-harm before each infusion; report new or worse symptoms.
- Watch for rash, swelling, wheezing or low blood pressure during and after the infusion; teach that reactions can appear days later.
- Ask about vaccines received in the past month.

## Pregnancy and breastfeeding

Effects on the fetus are not known; effective contraception may be advised during treatment and for 4 months after the last dose.

## Memory aid

BELImumab = BLyS-Eliminating Lupus Immunotherapy.

## Test yourself

Think of the answer, then tap the question to see it.

## What does belimumab bind?

Soluble BLyS (BAFF), a B-cell survival factor.

## Which psychiatric warning comes with belimumab?

Depression and suicidal thoughts or behaviour.

## Which kidney complication of lupus is an indication for belimumab?

Lupus nephritis.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/belimumab/)

## Related drugs

- [Abatacept](https://durgical.com/en/pharmacology/abatacept/)
- [Basiliximab](https://durgical.com/en/pharmacology/basiliximab/)

## Related conditions

- [Systemic lupus erythematosus](https://durgical.com/en/conditions/systemic-lupus-erythematosus/)
- [Lupus nephritis](https://durgical.com/en/conditions/lupus-nephritis/)

[← Back to the class: Other immunomodulating biologics](https://durgical.com/en/pharmacology/classes/other-immunomodulating-biologics/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Belimumab Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a611027.html) (MedlinePlus (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 39 (McGraw Hill, 2023); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L04AG04) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/belimumab/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/belimumab/