This study provides subjects who complete the BEL113750 study and subjects who complete the
open-label extension of HGS1006-C1115 (referred to as C1115) Study in Japan the option of
continuing treatment with belimumab (10 mg/kg intravenously every 4 weeks) for those
randomized to belimumab, or the option to begin treatment with belimumab for those randomized
to placebo, as an add-on to their standard of care SLE therapy.