Phase 3 Extension Study to Evaluate Long-term Safety of Ianalumab in Participants With Systemic Lupus Erythematosus (SIRIUS-SLE Extension).

Key Inclusion Criteria:

* Signed informed consent prior to participation in the extension study. Parent or legal guardian's signed informed consent and child's assent, if appropriate, are required before any assessment is performed for participants \<18 years of age. Of note, if the participant reaches age of consent (age as per local law) during the study, they will also need to sign the corresponding study Informed Consent Form (ICF) at the next study visit.
* Participants must have participated in either one of the two SIRIUS-SLE core studies, CVAY736F12301 or CVAY736F12302, and have completed the treatment period through Week 60 without treatment discontinuation.
* In the judgement of the investigator, participants must be expected to clinically benefit from continued study treatment.

Key Exclusion Criteria:

* Use of prohibited therapies.
* Active viral, bacterial or other infections requiring intravenous or intramuscular treatment for clinically significant infection which in the opinion of the investigator will place the participant at risk for participation.
* Plans for administration of live vaccines during the study period.
* Pregnant or nursing (lactating) women.

Other protocol-defined inclusion/exclusion criteria may apply.