Inclusion criteria: <br>Patients must meet the following criteria to be eligible for study entry. Documentation of each specific criterion must be present in the patient’s chart notes:<br><br>1. Age 16 years or above at the time of the screening, unless the inclusion of minors is prohibited by the local regulations.<br><br>2. Ability and willingness to provide written informed consent (or to obtain consent from a parent guardian where applicable) and to comply with the schedule of protocol requirements.<br><br>3. Diagnosis of SLE according to ACR criteria. At least 4 criteria must have been present for the diagnosis of SLE. The 4 criteria do not have to be present at the time of screening.<br><br>4. Active lupus nephritis defined as follows: Biopsy proven (within 6 months prior to randomization) WHO or ISN Class III or IV LN (excluding III (C), IV-S (C) and IV-G (C),<br>Patients are permitted to have co-existing Class V (see Table 1). Whenever possible, biopsies should be graded and reported following ISN/RPS classification scheme. AND The presence of: Urinary protein to Urinary creatinine ratio = 1. The proteinuria must not have improved by = 50% in the preceding 6 months. The urine sample used to define this ratio is the 24 hour screening sample which is measured by the central laboratory. If collection and analysis of a 24 hour urine sample is not possible prior to randomization then a timed urine collection (at least 12 hours) should be obtained. <br>Determination of eligibility based on a first-void morning 'spot' urine sample is acceptable if collection and analysis of a timed urine sample is not possible prior to randomization.<br><br>5. For patients of reproductive potential (males and females), a reliable means of contraception must be used for the duration of the study (e.g. hormonal contraceptive, intrauterine device, physical barrier) according to local guidelines and the treating physician’s recommendations. The relevant section of the product label for CYC, MMF or AZA (as appropriate) should be followed.<br><br>6. Female patients of childbearing potential must have a negative serum pregnancy test from the screening visit prior to enrollment at Day 1.<br>Are the trial subjects under 18? yes<br>Number of subjects for this age range: <br>F.1.2 Adults (18-64 years) yes<br>F.1.2.1 Number of subjects for this age range <br>F.1.3 Elderly (>=65 years) yes<br>F.1.3.1 Number of subjects for this age range <br>