Efficacy and Safety of Switching From Anti-C5 Antibody Treatment to Iptacopan Treatment in Study Participants With Atypical Hemolytic Uremic Syndrome (aHUS)

Inclusion Criteria:

* Male and female adult participants ≥ 18 years of age with diagnosis of aHUS for whom etiologies of other types of TMA and non-aHUS kidney disease have been excluded.
* Currently on the recommended weight-based dosage regimen of anti-C5 antibody treatment for at least 3 months prior to the screening visit.
* Clinical evidence of response to anti-C5 antibody treatment (in absence of PE/PI) for at least 3 months prior to entering the screening period as defined by:

1. Hematological normalization in platelet count ≥150 x 109/L and LDH below upper limit of normal \[ULN\], and
2. Stable or improving kidney function as defined by ≤15% increase in serum creatinine.
* Vaccination against Neisseria meningitidis and Streptococcus pneumoniae infections is required prior to the start of treatment with iptacopan.
* If not received previously or if a booster is required, vaccination against Haemophilus influenzae infection, should be given, if available and according to local regulations.

Exclusion Criteria:

* History of aHUS disease relapse while on anti-C5 antibody treatment.
* eGFR \< 30 ml/min/1.73m\^2
* Active infection or history of recurrent invasive infections caused by encapsulated bacteria, i.e., meningococcus, pneumococcus (eg., N. meningitidis, S. pneumoniae) or H. influenzae.
* Participants with sepsis or active systemic bacterial, viral (including COVID-19) or fungal infection within 14 days prior to study treatment administration.
* Kidney, bone marrow transplant (BMT)/hematopoietic stem cell transplant (HSCT), heart, lung, small bowel, pancreas, liver transplantation or any other cell or solid organ transplantation
* Female patients who are pregnant or breastfeeding, or intending to conceive during the course of the study
* Any medical condition deemed likely to interfere with the patient's participation in the study