The purpose of this study is to evaluate the efficacy and safety of an intravenous treatment regimen of two doses of anifrolumab versus placebo in adult subjects with active proliferative lupus nephritis (LN).

This is a Phase 2, multicentre, multinational, randomised, double-blind, placebo-controlled study to evaluate the efficacy and safety of two intravenous (IV) treatment regimens of anifrolumab versus placebo while taking standard of care (SOC) treatment with mycophenolate mofetil (MMF) and corticosteroids in adult subjects with active proliferative lupus nephritis (LN).

Main Inclusion Criteria:

1. Age 18 through 70 years at the time of screening

2. Fulfils at least 4 of the 11 criteria of the revised 1982 ACR classification criteria for SLE, at least one of which must be:

   1. Positive antinuclear antibody (ANA) test (1:40 or higher) or
   2. Elevated anti-dsDNA antibodies at screening (reported as equivocal or positive results), as per the centrallaboratory; or
   3. Anti-Smith antibody at screening elevated to above normal (ie, positive or equivocal results) as per the central laboratory

3. Class III (±Class V) or Class IV (±Class V) LN according to the World Health Organisation (WHO) or 2003 ISN/RPS classification based on a renal biopsy obtained within 12 weeks prior to signing the ICF or during the screening period:

4. Urine protein to creatinine ratio >1 gm/gm (113.17 mg/mmol), obtained on a 24-hour urine collection at screening

5. Estimated glomerular filtration rate ≥35 mL/min/1.73 m2

6. Must not have active or latent TB on either chest radiograph or by Quantiferon gold test

7. Women of childbearing potential must have a negative serum beta-hCG test at screening and negative urine pregnancy test prior to the first dose of sponsor-provided MMF.

Main Exclusion Criteria:

1. Receipt of any investigational product (small molecule or biologic) or commercially available biologic agent within four weeks or 5 half lives prior to signing of the ICF, whichever is greater

2. Pure Class V membranous LN on a renal biopsy obtained within 12 weeks prior to signing ICF or during the screening period

3. Known intolerance to ≤1.0 gm/day of MMF

4. History of dialysis within 12 months prior to signing the ICF or expected need for renal replacement therapy (dialysis or renal transplant) within a 6 month period after enrolment

5. Subjects, who at the time of signing the ICF, received any of the following immunosuppressive therapies after their qualifying biopsy

   1. Oral corticosteroids >0.5 mg/kg/day for more than 8 weeks or
   2. Oral or IV pulse methylprednisolone >3.0 gm (cumulative dose) or
   3. IV cyclophosphamide >2 pulses of high-dose (≥0.5 gm/m2) or >4 doses of low dose (500 mg every 2 weeks) or
   4. Average MMF >2.5 gm/day (>1800 mg/day of enteric-coated mycophenolate sodium) for more than 8 weeks or
   5. Tacrolimus >4 mg/day for more than 8 weeks

6. Major surgery within 8 weeks before signing the ICF or major surgery planned during the study period

7. History of any non-SLE disease that has required treatment with oral or parenteral corticosteroids for more than a total of 2 weeks within the last 24 weeks prior to signing the ICF

8. Confirmed positive test for hepatitis B or hepatitis C

9. Any severe herpes infection at any time prior to randomization

10. Opportunistic infection requiring hospitalisation or parenteral antimicrobial treatment within 3 years prior to randomization (vaginal, oral and skin candidiasis is not an exclusionreason).

11. History of cancer, apart from:

    1. Squamous or basal cell carcinoma of the skin that has been successfully treated
    2. Cervical cancer in situ that has been successfully treated

12. Concurrent enrolment in another clinical study with an IP within 4 weeks prior to ICF signing or within 5 half-lives of the IP used in that clinical study, whichever is longer.

13. During screening (within 30 days before Day 1 [Week 0 visit]), any of the following:

    1. Aspartate transaminase (AST) >2.5×upper limit of normal (ULN)
    2. Alanine transaminase (ALT) >2.5×ULN
    3. Total bilirubin >ULN (unless due to Gilbert's syndrome [based on Investigator's judgement])
    4. Glycosylated haemoglobin (HbA1c) >8% (or >0.08) at screening (diabetic subjects only)
    5. Neutrophil count <1x103/μL (or <1.0 GI/L)
    6. Platelet count <25x103/μL (or <25 GI/L)
    7. Haemoglobin <8 g/dL (or <80 g/L).

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment:

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access.