Anifrolumab Study of Treatment Effectiveness in the Real World (ASTER) study will collect real world data to obtain a good understanding of the (sustained) clinical effect and patient quality of life outcomes among diagnosed SLE patients who initiate anifrolumab treatment. ASTER will generate critical real-world evidence on the benefits of adding anifrolumab to standard of care treatment for SLE in routine clinical practice, to inform physicians, payers and patients.

ASTER is a multi-country, single-arm, prospective, observational study. The study will be initiated on a country-by country basis following the commercial launch of anifrolumab. ASTER is a cohort study, with 1-year retrospective baseline data and up to 5 years of follow-up data.

The minimum enrolment period is anticipated to be 18 months (± 5 months) per country, but it may be extended, if necessary, to reach the overall study target.

In general, patients will enter the study between the first anifrolumab prescription and infusion (index), with follow-up until death, loss to follow-up, patient discontinuing the study, or end of study period (whichever occurs first). Data collection will continue for all patients including those who have discontinued anifrolumab during the study, unless the patients have withdrawn their consent for participation in the study. Relevant clinical data collection will continue for the entire follow up while patient reported outcome (PRO) data collection will continue only up to the 3-year follow up.

The study will use clinical assessments that are relevant for SLE-treating physicians in routine clinical practice, as well as introduce a specific measure for skin manifestations to affirm the potency of anifrolumab in treating SLE-related skin manifestations.

The eCRFs will be accessed through secure web-based portals and will be used to ensure consistent data collection for each healthcare provider involved in this study.

Electronic data collection will be the only method of data collection in this study.

Inclusion Criteria:

• Fulfilled the 2019 EULAR (European League Against Rheumatism)/ACR (American College of Rheumatology) criteria for SLE at the time of study entry.
• Prescribed anifrolumab for their SLE treatment for the first time, according to approved country-specific label.
• The Physician's decision to prescribe anifrolumab must occur prior to any study-related discussion.
• In countries where prescription reimbursements are authorised on a case-by-case basis, authorisation (ie, patient access to treatment) will be required for study entry.

Exclusion Criteria:

• Currently participating in an anifrolumab early access/compassionate use program or an interventional clinical trial with an investigational product.
• Any previous exposure to anifrolumab (including as part of a clinical trial or early access programme).
• Documented diagnosis of severe or rapidly progressive Class III or IV glomerulonephritis requiring induction therapy (mycophenolate mofetil [MMF]/cyclophosphamide [CYC] + high dose steroids), isolated Class V lupus nephritis (in absence of other SLE manifestations, ie. skin/joint involvement), or active severe or unstable neuropsychiatric lupus.
• Any other condition which the investigator deems to limit a patient's ability to understand the informed consent.

All patients aged ≥18 years diagnosed with SLE who initiate anifrolumab as prescribed by their healthcare provider (HCP) per the approved country-specific label and are treated at the study sites will be eligible for inclusion.

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:

https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the deidentified 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. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.