BLISS-SC phase III trial of Benlysta (belimumab) shows benefits in systemic lupus erythematosus- GlaxoSmithKline

GlaxoSmithKline announced results from the BLISS-SC Phase III pivotal study of Benlysta (belimumab) administered subcutaneously in patients with active, autoantibody-positive systemic lupus erythematosus (SLE). These results showed that belimumab 200mg administered weekly via subcutaneous injection plus standard of care (SoC), showed significantly greater reductions in disease activity compared to placebo plus SoC. For the primary efficacy endpoint (systemic lupus erythematosus responder index (SRI) at Week 52), significantly more patients treated with belimumab administered subcutaneously plus SoC (60.8%) showed reduced disease activity compared to placebo plus SoC (48.5%).

SRI is a comprehensive composite endpoint measure, used in the pivotal Phase III BLISS clinical trial programme for belimumab administered intravenously. The SRI components measure reduction in disease activity defined as clinical improvement with no significant worsening in any organ system and no worsening in overall patient condition (PGA).

For the two pre-specified secondary efficacy endpoints, the study showed that the time to severe flare was significantly delayed in patients receiving belimumab administered subcutaneously plus SoC (170 days) compared to those on placebo plus SoC (117 days). In addition, in patients receiving more than 7.5 mg/day of prednisone (n=503), 18.2% of patients receiving belimumab administered subcutaneously plus SoC in the study were able to reduce their steroid dose by 25% or more to <7.5 mg/day during Weeks 40–52, compared with 11.9% of those on placebo plus SoC, but this did not reach statistical significance. The overall safety profile of belimumab in BLISS-SC was consistent with that observed in the two previous BLISS studies (BLISS-52 and BLISS-76). The overall incidence of treatment-related adverse events (AEs) was 31.3% with belimumab administered subcutaneously plus SoC vs 26.1% with placebo plus SoC. The data are being presented at the American College of Rheumatology/Association for Rheumatology Health Professionals Annual Meeting.