BLyS/BAFF Inhibitor (Anti-B-Lymphocyte Stimulator) Pregnancy: Benlysta should not be used during pregnancy unless the potential benefit justifies the potential risk to the foetus. There are limited data from use in pregnant women; post-marketing pregnancy registry data are too small a sample for definitive conclusions on birth defect risk. Women of childbearing potential must use effective contraception during treatment and for at least 4 months after the last treatment. Breast-feeding: it is unknown whether belimumab is excreted in human milk; because maternal IgG is excreted in breast milk, a decision should be made whether to discontinue breast-feeding or to discontinue therapy, taking into account the benefit of each.

Belimumab (Cutaneous Lupus)

Brand names: Benlysta

Belimumab is a monoclonal antibody used as add-on therapy in active autoantibody-positive systemic lupus erythematosus, including patients with cutaneous lupus manifestations.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 10 mg/kg on Days 0, 14 and 28, and at 4-week intervals thereafter (SPC regimen for SLE and for active lupus nephritis - see the indication caveat in notes)

Route: Intravenous infusion over a 1-hour period; must be reconstituted and diluted before administration and must not be given as an intravenous bolus

Frequency: Days 0, 14 and 28, then every 4 weeks

INDICATION CAVEAT - READ FIRST: the fetched UK SPC (Benlysta 120 mg powder for concentrate for solution for infusion) states this posology for patients with SLE or active lupus nephritis. It carries no separate cutaneous lupus indication and no cutaneous lupus regimen. The dose above is the labelled SLE/lupus nephritis regimen reproduced faithfully; the clinician must confirm whether it is the intended regimen for this cutaneous lupus page, and no cutaneous-lupus-specific dose has been inferred. Treatment should be initiated and supervised by a qualified physician experienced in the diagnosis and treatment of SLE, and infusions administered by a healthcare professional trained in infusion therapy. Premedication including an antihistamine, with or without an antipyretic, may be administered before the infusion. Administration may result in severe or life-threatening hypersensitivity and infusion reactions, including several hours after the infusion and with recurrence after initial treatment of symptoms - administer where resources to manage such reactions are immediately available, and keep patients under clinical supervision for several hours following at least the first 2 infusions. The infusion rate may be slowed or interrupted if an infusion reaction develops, and must be discontinued immediately for a potentially life-threatening adverse reaction. SLE: consider discontinuing if there is no improvement in disease control after 6 months of treatment. ACTIVE LUPUS NEPHRITIS: Benlysta should be used in combination with corticosteroids and mycophenolate or cyclophosphamide for induction, or mycophenolate or azathioprine for maintenance. TRANSITION FROM INTRAVENOUS TO SUBCUTANEOUS: in SLE, the first subcutaneous injection should be given 1 to 4 weeks after the last intravenous dose; in lupus nephritis, the first 200 mg subcutaneous dose should be given 1 to 2 weeks after the last intravenous dose, and the transition may occur any time after the patient completes the first 2 intravenous doses. ELDERLY: data in patients 65 years and over are limited; use with caution, but dose adjustment is not required. HEPATIC IMPAIRMENT: no specific studies conducted; patients are unlikely to require dose adjustment.

Paediatric dose

Dose: 10 mg/kg

Route: Intravenous infusion over a 1-hour period (reconstituted and diluted; not as an intravenous bolus)

Frequency: Days 0, 14 and 28, then at 4-week intervals thereafter

Max: Not stated in the source

SLE only: the recommended dose regimen for children aged 5 years and older is 10 mg/kg on Days 0, 14 and 28, and at 4-week intervals thereafter. Safety and efficacy in children aged below 5 years have not been established (no data). LUPUS NEPHRITIS: safety and efficacy in children and adolescents aged below 18 years with severe active lupus nephritis have not been established (no data). The SPC states no cutaneous lupus paediatric regimen. Clinician to verify against a children's formulary before publication.

Dose adjustments

Renal

Belimumab has been studied in a limited number of SLE patients with renal impairment. On the basis of the available information, dose adjustment is not required in mild, moderate or severe renal impairment; caution is however recommended in severe renal impairment because of the lack of data.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

Patient weight (kg)

Verify in a children's formulary

Contraindications

Hypersensitivity to the active substance or to any of the excipients

Side effects

Bacterial infections; nasopharyngitis was the most frequently reported adverse reaction in SLE (5% or more of patients and at a rate at least 1% greater than placebo)
Upper respiratory tract infection, urinary tract infection and herpes zoster - the most frequently reported reactions (more than 5%) in active lupus nephritis
Infusion and hypersensitivity reactions, which can be severe and fatal - serious reactions affected approximately 0.9% of adult patients and included anaphylactic reaction, bradycardia, hypotension, angioedema and dyspnoea; risk is greatest with the first two infusions
Severe cutaneous adverse reactions - Stevens-Johnson syndrome and toxic epidermal necrolysis have been reported
Adverse reactions were reported in 84% of belimumab-treated patients versus 87% of placebo-treated patients; 7% of belimumab-treated SLE patients and 12.9% of lupus nephritis patients discontinued treatment because of adverse reactions. NOTE: the section 4.8 adverse reaction table was truncated at the source-fetch limit - the full frequency table must be checked against the SPC

Interactions

Rituximab - available data do not support co-administration with belimumab in patients with SLE; caution should be exercised if belimumab is co-administered with other B cell targeted therapy (section 4.4)
NOTE: no SPC section 4.5 content was captured in this bundle; the entry above is stated within section 4.4 - the full interaction section must be checked against the SPC

Clinical monograph

How it works

It binds and inhibits soluble B-lymphocyte stimulator (BLyS/BAFF), reducing survival of autoreactive B cells and autoantibody production.

Prescribing in practice

Serious and sometimes fatal infections can occur, so do not start during active infection and monitor closely throughout treatment.
Hypersensitivity and infusion or injection reactions can occur, including delayed reactions, so observe accordingly.
Depression and mood changes have been reported and should be assessed before and during treatment.

Monitoring

Monitor for infection, infusion or injection-site reactions and new or worsening mood disturbance during therapy.

Counselling the patient

Report fever or other signs of infection promptly.
Tell your team about any new low mood or anxiety.
Avoid live vaccines while receiving treatment.

Evidence & guidelines

Belimumab is recommended by NICE as an add-on option for certain patients with active autoantibody-positive systemic lupus erythematosus.

Reference: BLISS-76 trial (Furie et al. 2011); BLISS-52 trial (Navarra et al. NEJM 2011); NICE TA397; MHRA SPC Benlysta; BSR/BHPR Lupus Guidelines (2022); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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