Background: Background: Eculizumab (ECU) a complement component 5 (C5) inhibitor, is the current standard of care for patients with paroxysmal nocturnal hemoglobinuria (PNH). Ravulizumab (RAV) is engineered from ECU with the main advantage of having an extended 8-week (vs 2-week with ECU) dosing interval, which decreases treatment burden markedly. Hence, RAV is expected to become the new standard of care to treat PNH. In Switzerland, RAV was approved for PNH treatment in 2020. Aims: Aims: The objective of this study was to evaluate data from the PNH Swiss Soliris and Ultomiris Reimbursement Registry (SSURR) to assess key parameters for safety and effectiveness of ECU and to assess the adoption of RAV for PNH treatment by physicians under real-world conditions. Methods: Methods: The SSURR