Study of Edecesertib in Participants With Cutaneous Lupus Erythematosus (CLE)

Key Inclusion Criteria: * Either fulfill European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) 2019 classification criteria for systemic lupus erythematosus (SLE) and/or have biopsy confirmed Cutaneous Lupus Erythematosus (CLE) at any time. * Must have active CLE at screening and Day 1. Individuals with acute CLE (ACLE) must have involvement of 2 distinct body areas. * Cutaneous Lupus Erythematosus Disease Area and Severity Index activity - A (CLASI-A) score (excluding alopecia) of ≥ 8 and CLASI-A erythema score of ≥ 4 during screening and on Day 1. Individuals with SLE must have Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of ≥ 4 at screening. * Presence of at least 1 representative lupus skin lesion amenable to punch biopsy and individual willingness to undergo skin punch biopsy at 2 time points. * Must have documented prior intolerance or inadequate response at any time (per investigator judgement) to protocol-specified treatments. * Topical corticosteroids or topical calcineurin inhibitors. * Oral corticosteroids. * Any other nonbiologic standard-of-care therapy, including, but not limited to: chloroquine, quinacrine, hydroxychloroquine, azathioprine, mycophenolate mofetil (MMF), leflunomide, dapsone, or methotrexate (MTX). * Individuals willing to comply with all study visits and assessments. Key Exclusion Criteria: * Individuals with only chilblains lupus, lupus panniculitis, lupus tumidus and/or localized acute CLE involving only 1 distinct body area at screening and Day 1. * Have highly active SLE (including but not limited to lupus nephritis, neuropsychiatric SLE, and/or vasculitis). * Presence of active skin conditions other than cutaneous lupus that may interfere with assessing lupus-specific skin lesion(s) (eg, psoriasis, and/or drug-induced lupus). * Meet protocol-specified infection or lab criteria. * Any active infection that is clinically significant (per investigator judgment). * Any history of clinically significant liver disease. * Significant cardiovascular disease. Note: Other protocol defined Inclusion/Exclusion criteria may apply.