A Study to Evaluate the Efficacy and Safety of Dapirolizumab Pegol in Study Participants With Moderately to Severely Active Systemic Lupus Erythematosus

Inclusion Criteria:

• Rescreening will be allowed once during the study in case there is new evidence foran inclusion criterion that was not fulfilled at the first screening or in case astudy participant no longer meets an exclusion criterion or screening periodexceeded the maximum duration due to delays in screening processes

• Study participant must be ≥16 years of age, unless restricted by local regulation,at the time of signing the Informed Consent form (ICF)

• Study participants who have moderate to severe disease activity due to eitherpersisting active SLE or due to an acute worsening of SLE in the scope of frequentflaring/relapsing-remitting systemic lupus erythematosus (SLE) despite stablestandard of care (SOC) medication defined as: a. Diagnosed with SLE at least 24 weeks before the Screening Visit (Visit 1) studyentry by a qualified physician b. Classified by 2019 SLE European League AgainstRheumatism/American College of Rheumatology (EULAR/ACR) classification criteria forSLE c. With serological evidence for SLE at Screening as demonstrated by at least 1of the following: i) Evidence for anti-dsDNA (in central laboratory at Screening)ii) Either complement C3 < lower limit of normal (LLN) OR complement C4 <LLN ORelevated erythrocyte-bound complement C4d (where available) as measured by centrallaboratory iii) Antinuclear antibodies with a titer of at least 1:80 confirmed bycentral laboratory in combination with evidence of at least 1 of the following SLEtypical autoantibodies:

1. Anti-Smith (anti-Sm) antibodies (central laboratory) 2. Anti-Sjögren's syndromeantibody A (Anti-SSA) (Ro)/Anti-Sjögren's syndrome antibody B (anti-SSB) (La)autoantibodies (central laboratory) 3. Historic evidence for anti-dsDNAantibodies d. Moderately to severely active defined as

• British Isles Lupus Assessment Group Disease Activity Index 2004 (BILAG 2004) GradeB in ≥2 organ systems and/or a BILAG 2004 Grade A in ≥1 organ systems at Screeningand Baseline Visit AND

• Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) ≥6 at ScreeningVisit AND

• SLEDAI-2K without labs ≥4 at Baseline Visit e. Receiving the following SOC medication at stable dose:

• Antimalarial treatment in combination with corticosteroids and/orimmunosuppressants or as stand-alone treatment if justified OR Treatment withcorticosteroids and/or immunosuppressants if anti-malarial treatment is notpossible

Exclusion Criteria:

• Study participant has any medical or psychiatric condition (including conditions dueto neuropsychiatric systemic lupus erythematosus (SLE)) that, in the opinion of theInvestigator, could jeopardize or would compromise the study participant's abilityto participate in this study. This includes study participants with a lifethreatening condition

• Study participant has a history of an anaphylactic reaction to parenteraladministration of contrast agents, human or murine proteins, or monoclonalantibodies

• Study participant has a history of malignancy, except the following treated cancers:cervical carcinoma in situ, basal cell carcinoma, or dermatological squamous cellcarcinoma

• Study participant has an increased risk for thromboembolic events due to an ongoingheart disease or due to a medical device, including but not limited to vasculargraft, valvular heart disease, atrial fibrillation, or a heart rhythm disorder

• Study participant has evidence of human immunodeficiency virus (HIV) infection,agammaglobulinemias, T-cell deficiencies, or human T-cell lymphotropic virus-1infection

• Study participant had a reactivated latent infection (example, cytomegalovirus,herpes simplex virus, or herpes zoster infection) or opportunistic infection (including but not limited to, pneumocystis, cytomegalovirus, or severe herpeszoster infection) within 12 weeks prior to the first study medication infusion (Visit 2), or is currently receiving suppressive therapy for an opportunisticinfection

• Study participants who have received live/live attenuated vaccines within 6 weeksprior to the first study medication infusion

• Study participant has clinically significant active or latent infection

• Study participant has a mixed connective tissue disease, scleroderma, and/or overlapsyndrome of these diseases with SLE

• Study participant takes any protocol defined prohibited concomitant medication

• Study participant has previously been randomized within this study or participanthas previously been assigned to treatment with dapirolizumab pegol (DZP) in a studyevaluating DZP

• Study participant has participated in another study of an IMP within the previous 12weeks or 5 half-lives of the investigational medicinal product (IMP) whatever islonger or is currently participating in another study of an IMP

• Study participant has chronic kidney failure stage 4, manifested by estimatedglomerular filtration rate <30mL/min/1.73m^2, or serum creatinine >2.5 mg/dL, orparticipant has proteinuria >3 g/day, or protein: creatinine ratio >340 mg/mmol atthe Screening Visit