A Study to Test Whether Different Doses of BI 3000202 Help People With Systemic Lupus Erythematosus (SLE)

Inclusion Criteria:

1. Male and female adult patients from ≥18 years (or alternative age for adults basedon local regulations) to <75 years

2. Confirmed Systemic Lupus Erythematosus (SLE) diagnosis meeting the European LeagueAgainst Rheumatism/American College of Rheumatology (EULAR/ACR) classificationcriteria at least 24 weeks prior to screening

3. At least one of the following positive at screening: Antinuclear Antibodies (ANA) ≥1:80 or anti-double-stranded Deoxyribonucleic Acid (dsDNA) antibody or anti-Smithantibody

• Total Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score ≥6 points and clinical SLEDAI-2K score ≥4 points

4. At least 1 British Isles Lupus Assessment Group (BILAG) A and/or 1 BILAG B grade atscreening, with sufficient disease activity according to both investigator andadjudicator

5. On SLE background therapy with a maximum of 1 immunosuppressant and/or 1antimalarial for ≥8 weeks and at a stable dose for ≥4 weeks before screening and/ororal corticosteroids at a dose of ≤30 mg/day prednisone or equivalent, stable for ≥2weeks before screening (Visit 1) Further inclusion criteria apply.

Exclusion Criteria:

1. Drug-induced SLE

2. Scleroderma (except linear scleroderma that does not interfere with assessments ofSLE disease activity) or in the opinion of the investigator or adjudicator elementsof other connective tissue disease that would interfere with interpretation of testresults or SLE clinical assessments

3. Active or unstable lupus neuropsychiatric manifestations, including but not limitedto any condition as defined by BILAG A criteria in the neuropsychiatric system, withthe exception of mononeuritis/mononeuropathy multiplex, chorea, and polyneuropathy

4. Lupus nephritis that may require a change in immune-modulating treatment or whichdemonstrates serum creatinine that is unstable or >2 × Upper Limit of Normal (ULN)and/or Urine Protein Creatinine Ratio (UPCR) that is unstable or > 3mg/mg (339mg/mmol)

5. Oral corticosteroids (prednisone or equivalent) >30 mg/day at screening Furtherexclusion criteria apply.