Cohort 1 will consist of 12 subjects (6 AMG 557: 6 placebo) randomized to receive AMG 557 210 mg or matching placebo. Cohort 2 will consist of 12 subjects (6 AMG 557: 6 placebo) randomized to receive AMG 557 140 mg or matching placebo. Enrollment of Cohort 2 (140 mg) will be initiated after enrollment of Cohort 1 (210 mg) is completed. After Cohort 1 and 2 enrollment has been completed, the emerging PK and PD data will be reviewed to determine if an additional 4-8 subjects with SCLE will be enrolled into the study to address equivocal results from the study. These 4-8 additional subjects will receive the same dose of either 210 mg or 140 mg SC (in an allocation ratio of 1 AMG 557: 1 placebo).~In addition, an open label extension study for participants in this study may be instituted following completion and analysis of results of this study. Initiation of this study will require that an acceptable risk-benefit profile and some evidence of efficacy are observed in the current study.
This study will be a multicenter, randomized, double-blind, placebo-controlled, multiple dose study in which approximately 24 subjects with SCLE will be enrolled. Cohort 1 will consist of 12 subjects (6 AMG 557: 6 placebo) randomized to receive AMG 557 210 mg or matching placebo. Cohort 2 will consist of 12 subjects (6 AMG 557: 6 placebo) randomized to receive AMG 557 140 mg or matching placebo. Enrollment of Cohort 2 (140 mg) will be initiated after enrollment of Cohort 1 (210 mg) is completed.