FDA approved belimumab (Benlysta, Human Genome Sciences and GlaxoSmithKline) for the treatment of adult patients with active, autoantibody-positive systemic lupus erythematosus (SLE) who are receiving standard therapy.
Belimumab is the first in a new class of drugs called B-lymphocyte stimulator (BLyS)-specific inhibitors. BLyS is a naturally occurring protein that was discovered by HGS in 1996. Belimumab is made available as a lyophilized powder in single-use vials for intravenous infusion only and must be reconstituted and diluted by a healthcare professional prior to administration.
Prior to belimumab, FDA last approved drugs to treat lupus in 1955—hydroxychloroquine (Plaquenil, Sanofi-aventis) and corticosteroids. Aspirin was approved to treat lupus in 1948.
Two clinical studies involving 1,684 patients with lupus demonstrated the safety and effectiveness of belimumab. In the studies patients diagnosed with active lupus were randomly assigned to belimumab plus standard therapy, or an inactive infused solution (placebo) plus standard therapy. The studies excluded patients who had received prior B-cell targeted therapy or intravenous cyclophosphamide, and those who had active lupus involving the kidneys or central nervous system.
Patients treated with belimumab and standard therapies experienced less disease activity than those who received placebo and standard of care medicines. Results suggested, but did not definitively establish that some patients had a reduced likelihood of severe flares, and some reduced their steroid doses.
African American patients and patients of African heritage participating in the 2 studies did not appear to respond to treatment with belimumab. The studies lacked sufficient numbers to establish a definite conclusion. To address this concern, the sponsor has agreed to conduct an additional study of people with those backgrounds to further evaluate the safety and effectiveness of belimumab for this subgroup of lupus patients.
Those receiving belimumab during clinical studies reported more deaths and serious infections compared with placebo. The drug should not be administered with live vaccines. The manufacturer is required to provide a Medication Guide to inform patients of the risks associated with belimumab.
The most common side effects in the studies included nausea, diarrhea, and fever (pyrexia). Patients also commonly experienced infusion reactions, so pretreatment with an antihistamine should be considered. “There are a number of pioneering biotechnology and pharmaceutical companies, involved in the research and development of new treatments for lupus, and our hope is that [the approval] will further stimulate additional companies to invest in new therapies for lupus,” said Sandra C. Raymond, president and CEO of the Lupus Foundation of America (LFA), Washington, D.C., in a company statement.