Efficacy and Safety Study of R935788 Tablets to Treat Systemic Lupus Erythematosus

Inclusion Criteria: * Patients must give written informed consent to participate in this study by signing an IRB/EC-approved Informed Consent Form (ICF) prior to admission to this study. * Males and females, 18 years of age or older, with active SLE diagnosed at least 6 months prior to Day 1 dosing. Active SLE is defined as having fulfilled the ACR criteria for SLE. * Patients of childbearing potential must be fully informed of the potential for R788 to adversely affect the fetus and, if sexually active, must agree to use an effective method of birth control during the study (oral contraceptive, mechanical barrier, long acting hormonal agent). * The patient must otherwise be in good health as determined by the investigator on the basis of medical history, physical examination, and laboratory screening tests during the screening period. * In the investigator's opinion, the patient has the ability to understand the nature of the study and any anticipated risks of participation, communicate satisfactorily with the investigator, and participate in and comply with the requirements of the entire protocol. Exclusion Criteria: * The patient has a history of, or a concurrent, clinically significant illness, medical condition or laboratory abnormality that, in the investigator's opinion, could affect the conduct of the study. * Clinically significant or uncontrolled medical disease in any organ system, other than due to SLE. * Background immunosuppressive therapy that has not remained stable ≤ 4 weeks prior to baseline. * Severe active or unstable renal disease. * Active severe neuropsychiatric SLE. * Female patients must not be breastfeeding and must have a negative urine pregnancy test per the Schedule of Study Activities. * The patient has a history of substance abuse, drug addiction, or alcoholism.