MSC2364447C Phase 1b in Systemic Lupus Erythematosus

Inclusion criteria

• Male or female of 18 to 65 years of age
• Diagnosis of systemic lupus erythematosus (SLE) (at least 4 of the 11 American College of Rheumatology [ACR] classification criteria for SLE) of at least 6 months duration at the Screening visit
• Positive test results for anti-nuclear antibody (ANA) (human epithelial cell-2 ANA greater than or equal to [>=] 1:80) and/or anti-dsDNA antibody (>= 30 international units per milliliter [IU/mL]) at the Screening visit
• At least 1 SLE disease manifestation (assessed by Systemic Lupus Erythematosus Disease Activity Index-2000 [SLEDAI-2K]) other than positive antidsDNA and no central nervous system (CNS) SLE (psychosis, organic brain syndrome, cranial nerve disorder, lupus headache, or new-onset cerebrovascular accident)
• History of vaccinations as follows or vaccination against these pathogens during Screening:

• Vaccination against Streptococcus pneumoniae with pneumococcal polysaccharide vaccine 23 or pneumococcal 13-valent conjugate vaccine as per local guidelines, and
• Vaccination against influenza virus (as per local seasonal recommendations). Subjects receiving 1 or more of these vaccinations during screening must have at least 2 weeks between the vaccination(s) and the date of randomization at Day 1.
• Other protocol defined inclusion criteria could apply

Exclusion criteria

• Active clinically significant CNS SLE
• Initiation or change in dose of anti-malarial treatment after the screening visit
• Within 2 weeks prior to Screening or during Screening: use of oral corticosteroids greater than (>) 40 mg daily prednisone equivalent, use of any injectable corticosteroids, or change in dose of corticosteroids
• Within 2 weeks prior to Screening, initiation or change in dose of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, or nonsteroidal anti-inflammatory drugs (NSAIDs).
• Within 2 months prior to Screening or during Screening: initiation of or change in dose of methotrexate, mycophenolate (mofetil or sodium), or azathioprine
• Within 2 months prior to Screening or during Screening, use of cyclosporine, tacrolimus, leflunomide, abatacept, anti-tumor necrosis factor alpha agents, intravenous immunoglobulin, plasmapheresis, or other disease-modifying, immunosuppressive, or immunomodulatory therapies not otherwise specified in protocol
• Within 6 months prior to Screening or during Screening: use of cyclophosphamide or chlorambucil
• Within 12 months prior to screening or during screening: use of rituximab, belimumab, or any other B cell-depleting or modulating therapies
• Within 1 month prior to Screening or during Screening, vaccination with live or live-attenuated virus vaccine.
• Active clinically significant viral, bacterial or fungal infection, or any serious episode of infection requiring hospitalization within the last 6 months - Estimated glomerular filtration rate by the Modification of Diet in Renal Disease equation of less than (<) 60 milliliter per minute per 1.73 square meter (mL/min/1.73 m^2), or recent decline in kidney function, or proteinuria >= 3 gram per day (g/day) (spot urine protein/creatinine ratio >= 3 mg/mg)
• Other protocol defined exclusion criteria could apply