BENLYSTA 400MG POWDER FOR SOL. FOR INFUSION

Indications

• Systemic lupus erythematosus (under expert supervision)
• Lupus nephritis (under expert supervision)

Dosage

Children: Refer to the BNF for Children for specific dosing guidance.

Adults: By intravenous infusion: 10 mg/kg every 2 weeks for 3 doses, then 10 mg/kg every 4 weeks. By subcutaneous injection: 400 mg once weekly for 4 doses, then 200 mg once weekly.

Mechanism of action

Belimumab binds to the soluble form of B-lymphocyte stimulator (BLyS) and inhibits its interaction with B cell receptors. This leads to a reduction in the survival of autoreactive B cells, thereby decreasing the production of autoantibodies and modulating the immune response in diseases like systemic lupus erythematosus.

Pharmacodynamics

Belimumab's pharmacodynamic effects include a decrease in B cell activity and autoantibody production, which contributes to the reduction of disease symptoms in lupus patients. Its immunosuppressive effects may help in controlling autoimmune processes, reducing flare frequency, and potentially improving health-related quality of life in affected individuals.

Pharmacokinetics

Belimumab exhibits a biphasic pharmacokinetic profile, with a distribution half-life of approximately 19 days and an elimination half-life of 15 days. It is primarily metabolized via proteolytic enzymes. The bioavailability varies based on the route of administration, with subcutaneous injection demonstrating a longer duration of action compared to intravenous infusion. Renal function may influence the pharmacokinetics of belimumab, necessitating caution in patients with impaired renal function.

Contra-indications

• Hypersensitivity to belimumab or any of its components
• Active or severe infections, including tuberculosis

Adverse effects

• Abdominal pain
• Upper respiratory disorders
• Skin reactions
• Sneezing
• Arthralgia
• Asthenia
• Dizziness
• Increased risk of infection
• Tachycardia
• Weight increase
• Leucopenia
• Neutropenia
• Pain
• Proteinuria
• Vertigo
• Gastrooesophageal reflux disease

Interactions

• May interact with other immunosuppressive agents
• Increased risk of infection when used with corticosteroids

Precautions

• Patients should be screened for latent and active tuberculosis before starting treatment
• Monitor full blood count, including neutrophil count before, during, and after treatment
• Monitor for signs and symptoms of infection during and after treatment
• Counsel patients on the effects on driving and skilled tasks due to dizziness and drowsiness

Pregnancy

Manufacturer advises to avoid unless potential benefit outweighs risk, no information available.

Breast-feeding

Manufacturer advises to avoid; consider if benefit outweighs risk, not known if present in human milk.

Storage

Store in a refrigerator (2–8 °C).

Formulations

• 10 mg/1 ml solution for injection (intravenous infusion)
• 400 mg once weekly for 4 doses, then 200 mg once weekly (subcutaneous injection)