Lupus Nephritis Pregnancy: Avoid — limited human data; may cause neonatal B-cell depletion. Effective contraception required during and for 4 months after last IV dose / 12 weeks after last SC dose.

Belimumab (Lupus Nephritis)

Brand names: Benlysta

Adult dose

Dose: 10 mg/kg IV every 2 weeks for 3 doses, then every 4 weeks. OR 200 mg SC once weekly.

Route: IV infusion over 1 hour, or subcutaneous injection

Frequency: IV: monthly (after loading). SC: weekly.

Max: 10 mg/kg per IV dose

BLyS (B-lymphocyte stimulator)/BAFF inhibitor. BLISS-LN trial: licensed for active lupus nephritis as add-on to standard of care (MMF/tacrolimus or cyclophosphamide). Assess response at 6 months — discontinue if no benefit.

Paediatric dose

Dose: 10 mg/kg

Route: IV infusion

Frequency: Every 2 weeks x3, then every 4 weeks

Max: 10 mg/kg per dose

Licensed from age 5 years for active SLE (not specifically lupus nephritis in children). Specialist paediatric rheumatology/nephrology input required.

Dose adjustments

Renal

No dose adjustment required; studied in lupus nephritis (eGFR down to ~30 in BLISS-LN). Avoid initiation if eGFR <30 (insufficient data).

Hepatic

No dose adjustment required for mild-moderate impairment

Paediatric weight-based calculator

Patient weight (kg)

Licensed from age 5 years for active SLE (not specifically lupus nephritis in children). Specialist paediatric rheumatology/nephrology input required.

Clinical pearls

BLISS-LN trial (Furie et al. NEJM 2020): belimumab + standard of care (MMF or cyclophosphamide/azathioprine) vs standard of care alone in active lupus nephritis — significant improvement in primary efficacy renal response at week 104 (43% vs 32%); also reduced risk of renal-related events by 49%
MHRA 2016: depression, suicidal ideation, and suicide cases reported with belimumab — screen for psychiatric history before starting; monitor mood during treatment. This signal led to Black Box warning in US.
Anti-dsDNA antibodies and complement (C3/C4) are useful markers to monitor SLE activity during belimumab treatment — decreasing anti-dsDNA + rising complement = improving disease control
IV vs SC route: SC 200 mg weekly has similar pharmacokinetics to IV 10 mg/kg monthly — SC offers home administration convenience but requires training and injection site reaction monitoring
6-month rule: if no renal response by 6 months of treatment — reassess the diagnosis and consider discontinuation; belimumab is not effective in all lupus nephritis subtypes

Contraindications

Active severe infection
Live vaccines within 30 days or during therapy
Previous anaphylaxis to belimumab
Hypersensitivity

Side effects

Serious infections (pneumonia, UTI, cellulitis)
Infusion reactions/hypersensitivity (premedicate with antihistamine +/- paracetamol)
Depression and suicidality (MHRA warning)
Nausea
Diarrhoea
Progressive multifocal leukoencephalopathy (PML — rare)

Interactions

Live vaccines — contraindicated within 30 days before or during therapy
Cyclophosphamide/other biologic immunosuppressants — insufficient safety data for combination; avoid routine co-use

Monitoring

Renal function (eGFR, proteinuria)
Anti-dsDNA, complement C3/C4
FBC
Depression/mood assessment
Infection signs
Urinalysis

Reference: BNFc; BNF 90; BLISS-LN Trial (Furie et al. NEJM 2020); MHRA DSU 2016 (Depression/Suicide); NICE TA397; SPC Benlysta. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Voclosporin · Lupus Nephritis

Pathways