BelimumabRx

Trade Name: Benlysta

Drug Class: B-lymphocyte stimulator (BlyS)-specific inhibitor

Preparations: 120 mg/vial, 400 mg/vial

Dose: 10 mg/kg as an IV infusion over 1 hour every 2 weeks for first 3 doses and every 4 weeks thereafter. Premedication to reduce infusion reactions is usual.

Indications: Active antibody positive SLE

Mechanism of Action: A human IgG1 monoclonal antibody that blocks binding of soluble BlyS to its receptors on B-cells. Inhibits B-cell survival and differentiation.

Contraindications: Hypersensitivity, active infection

Precautions: In clinical trials increased mortality and depression. Risk of serious infections. Avoid live virus vaccines. Combination with other biologics or cyclophosphamide not recommended.

Monitoring: Monitor clinically for infection and depression

Pregnancy Risk: C

Adverse Effects
Common: Mild infusion reactions, nausea, diarrhea, nasopharyngitis
Less common: Depression, infection
Rare: Anaphylaxis, progressive multifocal leucencephalopathy

Drug Interactions: Concurrent use of immunosuppressants may increase risk of infection.

Patient Instructions: Avoid live virus vaccines, avoid pregnancy, call your doctor if an infection or fever develops that lasts more than a few days.

Comments: In clinical trials modestly effective, primarily for skin and musculoskeletal manifestations at 52 weeks but not at 76 weeks. Not evaluated in severe active lupus nephritis or central nervous system and not recommended. Unclear if African-Americans respond as well.

Clinical Pharmacology: Half-life is 19 days. Biologic agents are not metabolized and thus have few drug interactions.

Cost: $$$$$

BIBLIOGRAPHY

Furie R, Petri M, Zamani O, et al. A phase III, randomized, placebo-controlled study of belimumab, a monoclonal antibody that inhibits B lymphocyte stimulator, in patients with systemic lupus erythematosus. Arthritis Rheum 2011;63:3918-30. PMID: 22127708.