This is a multicenter observational retrospective-prospective study consisting of retrospective and prospective phases. Trial will include 2 visits for obtaining the patient's demographic and clinical data: the 1st is retrospective and the 2nd is prospective. The study will involve approximately 50 sites of the Russian Federation; in each site about 20 patients will be recruited. The total planned size of study population will be approximately 1000 patients enrolled to the retrospective phase of the study, from which ~ 600 patients will be enrolled to the prospective phase.

Systemic lupus erythematosus (SLE) is a systemic autoimmune rheumatic disease with variable clinical manifestations and an unpredictable course, affecting any organs or systems, which quite often develops over several months or years, with persistent or, conversely, rapidly changing clinical manifestations, an undulating course, alternating remissions and flares.

Currently, in Russia there is no exact data on the number of patients with active moderate to severe SLE in the population, since there is no unified system for regular monitoring of patients with SLE in the country. The systematic information about complications and comorbidities, about the treatment approaches and their effectiveness in the Russian population is also absent.

The Russian Federation consists of 85 regions with a total population of more than 145 million people. The regions differ in ethnic composition, age, gender, climate, ecology, economic level, prevalence of SLE in general and moderate to severe SLE in particular.

Thus, there is a need to perform a large-scale observational study in regions of the country with a sufficient size of population to obtain information on moderate to severe SLE epidemiology, clinical and demographic characteristics, to describe main clinical outcomes and evaluate existing associations between observed treatment patterns and clinical outcomes in real clinical practice.

Trial will include 2 visits for obtaining the patient's demographic and clinical data: the 1st is retrospective and the 2nd is prospective. To allow wide data coverage the study will involve approximately 50 sites of Russian Federation; in each site about 20 patients will be recruited.

Overall expected duration of the study (from the first patient inclusion to the last patient last visit) is about 13 months or until 1000 patients will be included in the retrospective phase and ~ 600 patients - in the prospective phase This observational study does not imply any intervention into a routine clinical practice, including choice of treatment modality or special methods of investigation.

Inclusion Criteria:

Inclusion criteria for the retrospective phase are:

1. Patients with the diagnosis of SLE (ICD code: M32) confirmed by medical records;

2. Patients with availability of data of at least one visit to the clinic in the medical records in the last 24 months prior to inclusion;

3. Age ≥ 18 years at the time of last patient's visit to the clinic.

   Additional inclusion criteria for the prospective phase are:

4. Signed and dated written informed consent in accordance with ICH-GCP and local law prior to inclusion in the prospective phase of the study;

5. Disease activity measured with SLEDAI-2K ≥ 6 despite of standard treatment at the time of inclusion in the prospective phase of the study

Exclusion Criteria:

Exclusion criteria for the retrospective phase are:

1. Regular use of genetically engineered biological drugs for SLE treatment within the last 24 months prior to inclusion;

2. Participation in any interventional trial since the last patient's visit to the clinic;

3. Presence of lupus nephritis class III/IV ± V at the moment of the last patient's visit to the clinic;

4. Presence of neuropsychiatric lupus at the moment of the last patient's visit to the clinic.

   Additional exclusion criteria for the prospective phase are:

5. Current use of genetically engineered biological drugs for SLE treatment;

6. Current participation in any interventional trial;

7. Presence of lupus nephritis Class III/IV ± V at the moment of patient's visit;

8. Presence of neuropsychiatric lupus at the moment of patient's visit;

9. An acute or chronic disease that, in the opinion of the investigator, limits the ability of patient to provide data on his/her health or participate in this study or influence the interpretation of the results.

It is planned to enrol ~ 600 patients with moderate to severe SLE. Before that approximately 1000 patients with confirmed diagnosis of SLE will be screened (retrospective phase).

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests 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 PhRMA 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 anonymized individual patient-level data via secure research environment Vivli.org.

Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.