The WILLOW Study With M5049 in SLE and CLE (SCLE and/or DLE) (WILLOW)

Inclusion Criteria: * Active CLE (SCLE and/or DLE) with a CLE disease area and activity index (CLASI-A) \>= 8 * Active SLE with presence of: CLASI-A \>= 8 and BILAG 2004 1B, C, D (that is \[i.e.\], No BILAG 2004 A and No BILAG 2004 \>= 2B) or BILAG 2004 \>= 1A or 2B and 1 or 2 of the following: Hybrid Safety of Estrogens in Systemic Lupus Erythematosus National Assessment (SELENA)-SLEDAI \>= 6 at Screening Visit and confirmed clinical hybrid SELENA-SLEDAI \>= 4 (excluding laboratory parameters) at Day 1 Visit and/or CLASI-A \>= 8 * Receiving a stable dose of at least one of the following standards of care therapies for lupus: Immunomodulator/immunosuppressant, oral corticosteroids, and/or topical corticosteroids * 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