March 10, 2011 (Updated March 15, 2011) — The US Food and Drug Administration (FDA) has approved the use of belimumab (Benlysta, Human Genome Sciences and GlaxoSmithKline) in combination with standard therapies to treat active autoantibody-positive systematic lupus erythematosus.
This is the first lupus drug to be approved since 1955, when the FDA approved hydroxychloroquine (Plaquenil) and corticosteroids. In 1948, aspirin was approved to treat lupus.
Belimumab is a B-lymphocyte stimulator protein inhibitor that is thought to decrease the amount of abnormal B cells, which is hypothesized to be a mechanism of action in lupus.
The safety and effectiveness of belimumab was demonstrated in 2 clinical trials that randomized a total of 1684 patients to receive either belimumab or placebo in combination with standard therapy. Treatment with belimumab plus standard therapy reduced disease activity and possibly decreased the number of severe flares and steroid use.
Patients with active lupus that involved the kidneys or central nervous system and those who were previously treated with a B-cell-targeted therapy or intravenous cyclophosphamide were excluded from participating in the trials.
Study participants of African American or African descent did not significantly respond to belimumab. Additional studies will be conducted to definitively determine the safety and efficacy of belimumab in this population.
Belimumab is not recommended in patients with severe active lupus nephritis or severe active central nervous system lupus or when given in combination with other biologics or intravenous cyclophosphamide, because it has not been studied in these settings.
The recommended dosage regimen for belimumab is 10 mg/kg intravenously, administered for a period of 1 hour, 2 weeks apart for the first 3 doses and 4 weeks apart hereafter. It is available as single-use vials of lyophilized powder containing 120 mg per vial or 400 mg per vial. For prevention of infusion reactions and hypersensitivity reactions, antihistamine premedication may be administered prophylactically. Healthcare providers prepared to manage anaphylaxis should administer belimumab, and patients should be monitored during and for an appropriate period after administration.
Common adverse effects reported with belimumab include nausea, diarrhea, fever, infusion-site reactions, nasopharyngitis, bronchitis, insomnia, extremity pain, depression, migraine, and pharyngitis. It is suggested that patients be treated with an antihistamine prior to a belimumab infusion.
A greater number of deaths and serious infections were reported in patients treated with belimumab than in those treated with placebo. Live vaccines should not be administered during treatment with belimumab.
Belimumab is contraindicated for patients who have had previous anaphylactic reactions to this drug. It should be used with caution in patients with chronic infections, because serious, and sometimes fatal, infections have been reported in patients receiving belimumab or other immunosuppressive agents. If a new infection develops during treatment, interrupting belimumab therapy should be considered.
Because depression and suicidality have been reported in clinical trials of belimumab, patients should be instructed to contact their physician if they experience new or worsening depression, suicidal thoughts, or other mood changes.
Use in Special Populations
Belimumab is considered to be a pregnancy Category C medication, as there have not been adequate and well-controlled clinical studies in pregnant women. However, immunoglobulin G antibodies, including belimumab, can cross the placenta, and belimumab should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. Women of childbearing potential should use adequate contraception during treatment and for at least 4 months after the final treatment with belimumab.
For nursing mothers, a decision should be made whether to discontinue breast-feeding or to discontinue belimumab, because maternal antibodies are excreted in human breast milk.
The safety and efficacy of belimumab are undetermined in children. In addition, clinical trials enrolled insufficient numbers of participants 65 years or older to assess their response. Belimumab should therefore be used with caution in elderly patients, and in black/African American patients, in whom response rates for the primary endpoint in clinical trials were lower in the belimumab group vs the placebo group.
For more information about belimumab, visit the FDA Web site.
Laurie Barclay, MD, contributed to this news article.
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Cite this: Belimumab Earns FDA Approval for Lupus - Medscape - Mar 10, 2011.