The primary purpose of this study is to evaluate the efficacy, safety, and tolerability of IMVT-1402 in participants with Cutaneous Lupus Erythematosus.

The study will consist of 3 periods:

Period 1: eligible participants will be randomized 1:1 to IMVT-1402 Dose 1 or placebo SC QW for 12 weeks.

Period 2: participants who completed Period 1 will receive IMVT-1402 Dose 1 SC QW for 14 weeks.

Period 3: after completion of Period 2, participants will be re-randomized 1:1 to blinded IMVT-1402 Dose 1 or Dose 2 SC QW for 26 weeks.

The total study duration per participant is approximately 61 weeks.

Inclusion Criteria:

• Have documented diagnosis of SCLE or CCLE that has been confirmed by biopsy with or without systemic LE manifestations.
• Have a total CLASI-A score of ≥10 at Screening and Day 1. Participants with a CLASI-A score of ≥8 and <10 are eligible if the score does not include alopecia and/or mucous membrane lesions.
• Have active CLE despite an adequate trial of conventional therapies.
• Are positive for at least one autoantibody at Screening.

Exclusion Criteria:

• Have known or suspected drug-induced CLE anti-phospholipid disease, or neuropsychiatric SLE.
• Have rapidly progressive nephritis.
• Have current inflammatory skin disease other than SCLE/CCLE that, in the opinion of the Investigator, could interfere with the inflammatory skin assessments or confound the disease activity assessments.

Note: Other protocol defined Inclusion/Exclusion criteria may apply