A Study to Characterize the Pharmacokinetics, Pharmacodynamics, and Safety of Anifrolumab in Adult Type I Interferon Test High Systemic Lupus Erythematosus Subject With Active Skin Manifestations

Inclusion Criteria:

1. Age 18 through 70 years

2. Diagnosis of paediatric or adult SLE for > 24 weeks and fulfilling ≥4 of the 11
American College of Rheumatology (ACR) classification criteria with at least one
being:

- Positive antinuclear antibody (ANA) or

- Elevated anti-dsDNA antibodies or

- anti-Smith (anti-Sm) antibodies

3. Interferon high test result

4. Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) activity score ≥
10

5. Currently receiving at least 1 of the following for treatment of SLE:

• Oral prednisone or equivalent of ≤40 mg/day for a minimum of 2 weeks prior to
signing the Informed Consent Form (ICF) and with stable dose for at least 2 weeks
prior to randomization

• Any of the following medications for at least 12 weeks prior to signing the ICF, and
at a stable doses for at least 8 weeks prior to randomization: (i) Azathioprine ≤200
mg/day (ii) Antimalarials (eg, chloroquine, hydroxychloroquine, quinacrine) (iii)
Mycophenolate mofetil ≤2 g/day or mycophenolic acid ≤1.44 g/day (iv) Oral,
subcutaneous (SC), or intramuscular methotrexate ≤25 mg/week (v) Mizoribine ≤150
mg/day

6. Must not have signs of active or latent tuberculosis (TB).

7. Must not be pregnant or breastfeeding.

Exclusion Criteria:

1. Active severe or unstable neuropsychiatric SLE

2. Active severe SLE-driven renal disease

3. Any severe herpes infection at any time

4. Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), or HIV infection.

5. Known history of a primary immunodeficiency (splenectomy, or any underlying condition
predisposing for infection

6. Receipt of any investigation product within 4 weeks or 5 half -lives prior to signing
of the ICF

7. History of cancer, apart from:

- Squamous or basal cell carcinoma of the skin if successfully treated.

- Cervical cancer in situ if successfully treated