PHILADELPHIA, Pennsylvania—It’s been about 50 years since there was a new drug approved specifically to treat lupus, and Benlysta™ (belimumab, formerly LymphoStat-B^®) appears poised to win this distinction.

Phase III data presented at the American College of Rheumatology Annual Scientific Meeting in Philadelphia, PA¹found that belimumab plus standard of care bested placebo plus standard of care in terms of reducing lupus disease activity, flare rates, and prednisone use, and increased time-to-first flare in patients with active systemic lupus erythematosus (SLE) at 52 weeks. Belimumab was safe when used in combination with standard of care for SLE, the study showed.

The trial, dubbed BLISS-52, is the first of 2 pivotal Phase 3 trials of the drug. Results of the second study, BLISS-76, are slated to be released Monday. If the results are positive and in-line with BLISS 52, Human Genome Sciences, Inc and GlaxoSmithKline PLC plan to submit marketing applications in the United States, Europe, and other regions in the first half of 2010.

“These data suggest that belimumab could emerge to play an important role in the future treatment of patients with SLE,” said Sandra V. Navarra, MD, a principal investigator of BLISS-52 and head of rheumatology at the University of Santo Tomas, Manila, the Philippines, in a written statement.

Benlysta moving down the pipeline

In BLISS-52, 865 patients with active SLE received either standard of care plus placebo or standard of care plus belimumab (1 or 10 mg/kg). Patients who received belimumab plus standard of care were more likely to respond, compared with counterparts who received placebo plus standard of care: 57.6% for 10 mg/kg belimumab, 51.4% for 1 mg/kg belimumab, and 43.6% for placebo. Response was based on the SLE Responder Index.

Time-to-first flare was also decreased in patients taking belimumab, compared with placebo, the study showed. Specifically, time to flare was 119 days for 10 mg/kg belimumab, 126 days for 1 mg/kg belimumab, and 84 days for placebo. Moreover, the risk of having severe SLE disease flares was reduced over 52 weeks by 43% in the 10 mg/kg belimumab treatment group and by 24% in the 1 mg/kg belimumab treatment group, the study showed.

A greater percentage of patients receiving belimumab achieved a reduction in SELENA SLEDAI score of at least 4 points by week 52, the researchers report. Patients taking belimumab were also able to cut back on steroids, compared to controls. Lupus patients who took the experimental drug also showed greater improvements in fatigue levels and quality of life measures when compared to counterparts who received placebo, the study showed.

Belimumab was generally well tolerated. The rates of adverse events, serious adverse events, infections, and fatalities were comparable between belimumab and placebo groups, the researchers report. Specifically, serious infections were reported in 5.9% of patients on placebo and 6.1% of patients on belimumab. Headache, arthralgia, upper respiratory tract infections, urinary tract infection and influenza were the most commonly reported adverse events. There were no malignancies seen in this study.

Reference

1. Navarra S, Guzman R, Gallacher A, et al. Belimumab, a BLyS-Specific Inhibitor, Reduced Disease Activity, Flares and Prednisone Use in Patients with Active SLE: Efficacy and Safety Results From the Phase 3 BLISS-52 Study. Presented at: American College of Rheumatology Meeting; October 17-21, 2009; Philadelphia, Penn. Presentation No. LB1.