Benlysta

Benlysta (belimumab) is an add-on therapy indicated for adult patients with active autoantibody-positive systemic lupus erythematosus (SLE) who have a high degree of disease activity (e.g., positive anti-dsDNA and low complement) despite standard therapy. The marketing authorization holder is Glaxo Group Limited. The drug is available in strengths of 120 mg and 400 mg, with an ATC Code of L04AA26. The application for marketing authorization was submitted on 4 June 2010.

Efficacy findings from clinical trials include a mean percent decrease in SELENA SLEDAI score of 11%. In one study, 35.6% of patients achieved a SELENA SLEDAI >=4 point reduction from baseline at Week 52, with an observed difference versus placebo of 7.17% (p-value 0.0869). Another study showed 42.8% of patients achieving this reduction, with an observed difference versus placebo of 11.25% (p-value 0.0062). The absolute bioavailability of belimumab after subcutaneous administration is 67.23%, with a Tmax of 5.0 days.

Safety data includes 1463 subjects with at least 3 months of exposure across all active treatment groups. In Phase 3 studies, 73 subjects in the 1 mg/kg group (out of 559 total subjects) and 5 subjects in the 10 mg/kg group were positive for anti-belimumab antibodies. Pre-clinical studies in monkeys showed 12 animals with detectable, treatment-emergent anti-belimumab antibodies, with 6 of these experiencing reduced belimumab serum concentrations due to antibodies.