The overall purpose of the study is to assess the efficacy of three different doses of BI 655064 against placebo as add-on therapy to standard of care (SOC) treatment for active lupus nephritis in order to characterize the dose-response relationship within the therapeutic range, and select the target dose for phase III development.

Inclusion criteria:

• Males and females 18-70 years. Women of childbearing potential must be ready and able (as assessed by investigator) to use simultaneously two reliable methods of birth control, one of which must be highly effective. Highly effective method, per ICH M3(R2) is a method that result in a low failure rate of less than 1% per year when used consistently and correctly.
• Diagnosis of systemic lupus erythematosus (SLE) by American College of Rheumatology (ACR) criteria 1997, at least 4 criteria must be documented, one of which must be a positive anti-dsDNA antibody OR a positive antinuclear antibody (ANA) at screening or around time of start of induction therapy
• Lupus Nephritis Class III or IV (International Society of Nephrology (ISN)/Renal Pathology Society (RPS) -2003 classification) with either active or active/chronic disease, co-existing class V permitted, proven by renal biopsy within 3 months prior to screening or during screening if induction therapy has not yet been started
• Active renal disease evidenced by proteinuria ≥ 1.0 g/day [(Uprot/Ucrea) ≥ 1]
• Signed and dated written informed consent

Exclusion criteria:

• Clinically significant current other renal disease

• Glomerular Filtration Rate <30ml/min/1.73m²

• Dialysis within 12m of screening

• Antiphospholipid syndrome

• Diabetes mellitus poorly controlled or known diabetic retinopathy or nephropathy

• Evidence of current or previous clinically significant disease, medical condition or finding in the medical examination that in the investigator's opinion would compromise the safety of the patient or the quality of the data

• Any induction therapy for Lupus Nephritis within the last 6 months prior to randomisation except induction with Mycophenolate Mofetil and high dose steroids started within 6 weeks prior to randomisation

  • Treatment with any biologic B-cell depleting therapy (e.g. anti-CD20, anti-CD22,) within 12 months prior to randomisation
  • Treatment with abatacept within 12 months prior to randomisation
  • Treatment with tacrolimus or cyclosporin within 4 weeks prior to randomisation
  • Treatment with cyclophosphamid within 6 months prior to randomisation
  • Treatment with investigational drug within 6 months or 5 half-lives, whichever is greater before randomisation

• Contraindication for MMF or corticosteroids and/or known hypersensitivity to any constituents of the study drug.

• Chronic or relevant acute infections, including but not limited to HIV, Hepatitis B and C and tuberculosis (including a history of clinical tuberculosis (TB) and/or a positive QuantiFERON TB-Gold test

• Any active or suspected malignancy or history of documented malignancy within the last 5 years before screening, except appropriately treated carcinoma in situ and treated basal cell carcinoma.

• Live vaccination within 6 weeks before randomisation

• Patients unable to comply with the protocol in the investigator's opinion.

• Alcohol abuse in the opinion of the investigator or active drug abuse .

• Women who are pregnant, nursing, or who plan to become pregnant while in the trial

• Impaired hepatic function, defined as serum Aspartate Transferase/Alanine Transferase, bilirubin or alkaline phosphatase levels > 2 x Upper Limit of Normal

• Further exclusion criteria apply.

Once the criteria in section "Time Frame" are fulfilled, researchers can use the following link https://www.mystudywindow.com/msw/datasharing to request access to the clinical study documents regarding this study, and upon a signed "Document Sharing Agreement".

Furthermore, researchers can request access to the clinical study data, for this and other listed studies, after the submission of a research proposal and according to the terms outlined in the website.

One year after the approval has been granted by major Regulatory Authorities and after the primary manuscript has been accepted for publication, or after termination of the development program.

For study documents - upon signing of a "Document Sharing Agreement". For study data - 1. after the submission and approval of the research proposal (checks will be performed by the sponsor and/or the independent review panel, including checking that the planned analysis does not compete with sponsor's publication plan); 2. and upon signing of a legal agreement.