BELIMUMAB (FULLY HUMAN MONOCLONAL ANTIBODY TO BLYS) REDUCED STEROID USE IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) PATIENTS DURING 3 YEARS OF THERAPY

E.M. Ginzler, D.J. Wallace, W. Chatham, J. McKay, R. Furie, J.T. Merrill, J. McCune, S.M. Wolfe, M.A. Dooley, D. Martin, J. Zhong, D. Hough, W. Freimuth, LBSL02/99 Study GroupSUNY Downstate, Brooklyn, NY; Cedars-Sinai UCLA, Los Angeles, CA; Univ of AL at Birmingham, Birmingham, AL; OK Center for Arthritis Therapy and Research, Tulsa; NSLIJHS, Lake Success, NY; OMRF, Oklahoma City, OK; Univ of Michigan, Ann Arbor, MI; STAT Research, Dayton, OH; Univ of NC, Chapel Hill, NC; HGS, Rockville, MD, United StatesObjectives: To assess the steroid use in patients with active SLE receiving belimumab treatment over 3 years of therapy.Methods: 449 SLE patients enrolled in a placebo controlled trial of belimumab (1, 4, 10 mg/kg, monthly) plus standard of care background therapy for 52 weeks, followed by 2 years open-label belimumab treatment. The use of steroids and steroid taper was standardized in the trial according to clinical need. Data was assessed through 3 years of belimumab therapy.Results: Baseline values of original cohort (n=449): mean SS score = 9.6; subjects with ≥1 BILAG A or 2 BILAG B flares = 68%; mean PGA = 1.5; 70% of subjects were on prednisone (mean 11 mg/day, range 1 to 40 mg/day) and 50% were on other immunosuppressants. In the first year of therapy among subjects taking > 7.5mg/day prednisone at baseline, up to 44% of belimumab-treated subjects were able to reduce prednisone use to ≤ 7.5mg/day compared with placebo-treated subjects, with differences between belimumab and placebo ranging from 10% to 19%. Among subjects taking 0-7.5mg/day of prednisone at baseline, <6% of belimumab-treated subjects required an increase in prednisone to > 7.5mg/day, with differences between belimumab and placebo ranging from 5% to 14%. With continuous use of belimumab (10 mg/kg) during years 2 and 3, the proportion of subjects reducing steroids continued to increase and the proportion of subjects requiring a steroid increase remained low. Steroid reduction Steroid increase Placebo Belimumab Placebo Belimumab 10 mg/kg 10 mg/kg n=48 n=38 n=65 n=73 Baseline dose (mg/kg) 16.3 (1.2) 15.8 (2.0) 3.6 (0.4) 2.9 (0.4) Week 8 6.3% 18.4% 10.8% 5.6% Week 26 19.6% 37.8% 14.5% 5.8% Week 40 25.0% 44.1% 16.1% 5.1% Week 52 34.2% 44.1% 17.2% 3.5% Year 2 NA 56.5% NA 4.0% Year 3 NA 61.9% NA 7.3% Subjects having an average prednisone dose decrease to ≤7.5 mg/day from >7.5 mg/day at baseline. Subjects having an average prednisone dose increase to >7.5 mg/day from ≤7.5 mg/day at baseline. Mean (standard error). NA = not applicable. Conclusion: These exploratory analyses suggest that belimumab may have potential steroid-sparing activity, with trends continuing over 3 years of observation.Citation: Ann Rheum Dis, volume 67, supplement II, year 2008, page 217Session: SLE, Sjögren's and APS – Clinical aspects and treatment