This study is to evaluate the safety, tolerability and pharmacokinetics (PK) of orally administered M5049 in participants with systemic lupus erythematosus (SLE) or cutaneous lupus erythematosus (CLE).

Inclusion Criteria:

• Active systemic lupus erythematosus (SLE) with a Cutaneous lupus erythematosus disease area and activity index (CLASI-A) greater than or equal to [>= ] 6 and/or at least one active SLE clinical manifestation according to Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K)
• Active cutaneous lupus erythematosus (CLE) (subacute cutaneous lupus erythematosus and/or discoid lupus erythematosus) with a CLASI-A >= 6
• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• Autoimmune or rheumatic disease other than SLE or CLE
• Dermatological diseases other than cutaneous manifestations of SLE or CLE
• Uncontrolled medical conditions including significant cardiovascular events, active lupus nephritis, and active neurological disorder
• Ongoing or active clinically significant viral, bacterial or fungal infection
• History of uncontrolled seizures or other neurological disorder
• History of or positive for human immunodeficiency virus, hepatitis C virus, or hepatitis B virus
• History of malignancy
• Other protocol defined exclusion criteria could apply

We are committed to enhancing public health through responsible sharing of clinical trial data. Following approval of a new product or a new indication for an approved product in both the US and the European Union, the study sponsor and/or its affiliated companies will share study protocols, anonymized patient data and study level data, and redacted clinical study reports with qualified scientific and medical researchers, upon request, as necessary for conducting legitimate research. Further information on how to request data can be found on our website https://bit.ly/IPD21