A Pilot Study of CC-220 to Treat Systemic Lupus Erythematosus.

The study consists of 2 parts. Part 1 is a randomized, double-blind, placebo controlled, ascending dose study to evaluate the safety and tolerability of CC-220 in SLE subjects. Subject participation in Part 1 consists of 3 phases: * Pre-treatment Screening Phase: up to 28 days prior to the first dose of the investigational product (IP) * Treatment Phase: up to 84 days * Observation Phase: 84 day post-treatment A total of approximately 40 subjects will be randomized into 4 dose groups with a 4:1 ratio of CC-220 (0.3 mg every other day \[QOD\], 0.3 mg everyday \[QD\], 0.6 mg and 0.3 mg on alternating days, and 0.6 mg QD) or matching placebo. In each dosing arm, 8 subjects will receive active drug and 2 subjects will receive placebo. The Treatment Phase will be up to 84 days in duration for all dose groups. Subjects who discontinue IP early and all subjects who complete the 84 day treatment phase will enter into the Observational Follow-up Phase for an 84 day period. A subject will be permitted to reduce their dose one time during Part 1 of the study. Part 2 is the Active Treatment Extension Phase (ATEP) which is an extension to evaluate the long-term efficacy and safety/tolerability of CC-220 in SLE subjects who completed Part 1 of the study. Subjects who complete the Treatment Phase of Part 1 of the study will be eligible to receive CC-220 in the ATEP for up to 2 years. All subjects who participate in the ATEP will receive either 0.3 mg QD or 0.6 mg and 0.3 mg QD on alternating days. Subjects who terminate the Treatment Phase of Part 1 early will not be eligible for entry into the ATEP. Subject participation consists of two phases: * Active Treatment Extension Phase: Up to 2 years * Observational Follow-up Phase: One month