SAN FRANCISCO, CA—A systematic review of belimumab for systemic lupus erythematosus (SLE) presented at the 2015 ACR/ARHP Annual Meeting found that at the US Food and Drug Administration (FDA)-approved dose of 10mg/kg, the agent “was associated with significantly more benefits compared to placebo.”
“We found overall quality of evidence to be high,” noted study coauthor Jasvinder A. Singh, MD, MPH, Professor of Medicine at the University of Alabama at Birmingham (UAB), Birmingham, AL.
Compared to placebo, the FDA-approved belimumab dose was associated with greater effects on the SLE Responder Index (SRI), the validated SELENA-SLEDAI (SLE Disease Activity Index), the British Isles Lupus Assessment Group (BILAG) and Physician Global Assessment (PGA) measures.
Compared with a belimumab dose 1mg/kg, the 10mg/kg dose was also associated with larger improvements in disease signs and symptoms and disease activity, Dr. Singh noted.
Using a search strategy developed by a Cochrane librarian, Dr. Singh and his UAB colleague, Dr. Nipam Shah, MBBS, MPH, searched multiple databases for eligible studies. They included randomized controlled trials or controlled clinical trials that compared belimumab, alone or in combination, with placebo or control treatment in adults with lupus. They independently assessed search results, trial quality, and risk of bias, and extracted data.
Drs. Singh and Shah identified four studies (n=2,205) for qualitative and/or quantitative analyses; an additional 5 studies pooled data from up to three of the original studies, they reported.
Their review of data from these studies showed that the FDA-approved dose of 10mg/kg belimumab “was associated with significantly more benefits compared to placebo in patients with lupus,” they concluded.
Compared with placebo, belimumab 10mg/kg was associated with significantly higher likelihood of achieving improvement/reduction in SELENA-SLEDAI score by ≥4 points and SRI at 52 weeks, they reported. Risk ratios were 1.29 (95% confidence interval [CI]: 1.10, 1.51) for SELENA-SLEDAI score and 1.31 (95% CI: 1.11, 1.55) for SRI.
Change in health-related quality of life, as assessed by improvement in the SF-36 Physical Component Summary score, was a mean of 1.35 units greater for belimumab 10mg/kg than placebo (95% CI: 0.68, 3.38). However, this change did not meet statistical or clinical significance of a 2.5 to 5 unit greater improvement (level of evidence, moderate).
No significant difference was observed between belimumab 10mg/kg and placebo in the proportion of patients with ≥1 serious adverse event (1.07 [95% CI: 0.79, 1.43]), ≥1 serious infection (0.97 [95% CI 0.55, 1.7]), or withdrawals due to adverse events (0.91 [95% CI 0.56, 1.47]; level of evidence, moderate).
“Mortality was rare, and did not differ significantly between belimumab 10mg/kg and placebo,” they reported.
The number needed to treat (NNT) for SRI at 52 weeks was 8 (95% CI: 5, 23) and the NNT for SELENA-SLEDAI at 52 weeks was 8 (95% CI: 5, 25).
“Evidence related to harms is inconclusive and of low quality,” the study authors noted.