Belimumab Safe in Adults With SLE: Analysis of Clinical Trial Data
4,170 patients were included in the pooled safety analysis
Belimumab continues to show a favorable risk-benefit profile in adults with systemic lupus erythematosus (SLE), according to safety data from six clinical trials.
Researchers noted the findings “add to the evidence base supporting a positive benefit-risk profile of belimumab in the treatment of adult patients with SLE.”
Data from the analysis was detailed in the study, “Safety of belimumab in adult patients with systemic lupus erythematosus: Results of a large integrated analysis of controlled clinical trial data,” published in Lupus.
SLE, the most common form of lupus, is an autoimmune disease that may affect multiple systems in the body. Its treatment depends on the type and intensity of symptoms and the organs involved, with corticosteroids, antimalarial agents, non-steroid anti-inflammatory medications, and immunosuppressants being often recommended.
Belimumab, sold under the brand name Benlysta, is a human monoclonal antibody that binds and inhibits B-lymphocyte stimulator, a protein that promotes the survival of antibody-producing immune B-cells. By doing so, it’s expected to lower the number of B-cells that contribute to the production of the harmful self-reactive antibodies that drive SLE.
The therapy is approved to treat patients ages 5 and older with active autoantibody-positive SLE as well as adults with lupus nephritis who’re also receiving standard treatments. Lupus nephritis is a common SLE complication that arises when self-reactive antibodies attack and damage the kidneys.
Several clinical trials demonstrated the safety and effectiveness of belimumab in SLE patients when used together with standard treatments.
A team led by U.S. researchers analyzed safety data from six clinical trials of belimumab in adults with SLE to document its safety in a larger and diverse patient population.
The six studies included patients from different parts of the world of several races and ethnicities (white, Black/African, Asian, and Hispanic/Latino). Patients were at least 18, diagnosed with autoantibody-positive SLE, and under a stable treatment regimen for at least 30 or 60 days (depending on the study) before the first placebo or belimumab dose was administered.
Researchers analyzed data from one Phase 2 study (NCT00071487) and five Phase 3 trials — BLISS-52 (NCT00424476), BLISS-76 (NCT00410384), BLISS-NEA (NCT01345253), EMBRACE (NCT01632241), and BLISS-SC (NCT01484496) — wherein patients received at least one dose of a placebo or belimumab plus standard therapy. In most studies, medications were administered on days 1,14, and 28, and every 28 days thereafter.
In total, 4,170 patients treated with either belimumab (2,815 patients) or a placebo (1,355 patients) with standard therapy for 52 weeks (around a year) were included in the pooled safety analysis.
Side effects in SLE patients
Most patients in both treatment groups were female (93.6% in placebo group, 94.5% in belimumab group), with a mean age of around 38. White was the most common race in the two treatment groups (placebo, 38.1% vs. belimubab, 39.1%), followed by Asian (placebo, 30.8% vs. belimubab, 29.7%), and Black/African ancestry (placebo, 19.9% vs. belimubab, 20.2%).
The incidence of side effects, including serious and life-threatening events, was similar in both placebo and belimumab-treated patients (87.4% vs. 86.7%) and consistent with data from individual studies. No new side effects were identified.
The most commonly described serious side effects were infections/infestations, including pneumonia, urinary tract infection, and cellulitis (placebo, 5.9% vs. belimumab, 5.4%). Some patients had kidney/urinary disorders, including lupus nephritis, excess protein in the urine, and acute kidney injury (placebo, 2.2% vs. belimumab, 1.7%), and musculoskeletal and connective tissue disorders (placebo, 2.1% vs. belimumab, 1.7%).
Mortality rates were also similar between the groups: 0.4% for placebo and 0.6% for belimumab-treated patients, with the most common causes being infections and vascular events.
“The pooled safety data were consistent with those observed in the individual studies,” the researchers wrote, adding “collectively, this evidence continues to support a positive benefit-risk profile of belimumab in the treatment of adult patients with SLE.”