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Purpose: Most patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with a complement protein 5 (C5) inhibitor achieve full control of terminal complement activity and intravascular hemolysis. The minority remains anemic and transfusion dependent despite this control. Etiology for ongoing anemia is multifactorial and includes bone marrow failure, breakthrough hemolysis, extravascular hemolysis (EVH) and nutritional deficiencies. Patients and Methods: To evaluate the potential etiologies of hemoglobin levels < 10 g/dL despite receiving C5 inhibitor therapy, we performed a retrospective US chart review of adult patients with PNH and treated for at least 12 months with eculizumab (n=53), ravulizumab (n=32), or eculizumab followed by ravulizumab (n=15). Clinically evident EVH was defined as at least one transfusion, reticulocyte count ≥ 120× 109/L and hemoglobin level ≤ 9.5 g/dL. Safety data were not collected. Mean treatment duration was 26.5± 17.2 months. Results: Treatment with C5 inhibitors significantly improved hemoglobin, lactate dehydrogenase, and number of transfusions versus baseline. Among the patients with hemoglobin < 10 g/dL during the last 6 months of treatment (n=38), one patient (eculizumab) had clinically evident EVH, and 10 patients had active concomitant bone marrow failure. Bone marrow failure was a major contributor to hemoglobin < 10 g/dL and transfusion dependence; clinically evident EVH was uncommon. Conclusion: A range of hematologic causes need to be considered when evaluating anemia in the presence of treatment with a C5 inhibitor. [ABSTRACT FROM AUTHOR]

This study developed and explored a novel composite endpoint to assess the overall impact that treatment can have on patients living with paroxysmal nocturnal hemoglobinuria (PNH). Candidate composite endpoint variables were selected by a group of experts and included: lactate dehydrogenase levels as a measure of intravascular hemolysis; complete terminal complement inhibition; absence of major adverse vascular events, including thrombosis; absence of any adverse events leading to death or discontinuation of study treatment; transfusion avoidance; and improvements in fatigue‐related quality of life as determined by the Functional Assessment of Chronic Illness Therapy (FACIT)‐Fatigue score. From these variables, a novel composite endpoint was constructed and explored using data collected in the ravulizumab PNH Study 301 (NCT02946463). Thresholds were defined and reported for each candidate variable. Five of the six candidate variables were included in the final composite endpoint; the FACIT‐Fatigue score was excluded. Composite endpoint criterion was defined as patients meeting all five selected individual component thresholds. All patients in the ravulizumab arm achieved complete terminal complement inhibition and a reduction in lactate dehydrogenase levels; 51.2% and 41.3% of patients in the ravulizumab arm and eculizumab arm, respectively, achieved all composite endpoint component thresholds (treatment difference: 9.4%; 95% confidence interval: −3.0, 21.5). The composite endpoint provided a single and simultaneous measurement of overall benefit for patients receiving treatment for PNH. Use of the composite endpoint in future PNH research is recommended to determine clinical benefit, and its use in health technology assessments should be evaluated. [ABSTRACT FROM AUTHOR]

Objectives: Although complement inhibition is highly effective, patients with paroxysmal nocturnal hemoglobinuria (PNH) may experience intravascular breakthrough hemolysis (BTH). Underlying causes may include elevated free C5, pregnancy, or non-pregnancy complement-activating conditions (e.g. infections). This study compared BTH-related resource utilization and costs in PNH patients treated with eculizumab versus ravulizumab. Methods: A cost model was developed using data from a targeted literature review and a survey of experienced clinicians. Costs associated with BTH episodes were calculated by cause and weighted by the proportion attributed to each cause and the cost of treating each episode. The model captured direct medical costs in 2018 US dollars. Annual BTH-related healthcare resource utilization was also calculated. Results: BTH episodes in the literature were commonly associated with elevated lactate dehydrogenase and aspartate aminotransferase, hemoglobinuria, transfusion needs, and/or recurrence of PNH symptoms. The majority of BTH management costs in eculizumab-treated patients related to changing from the approved dosing regimen following an episode of BTH, rather than acute management. No ongoing dosing changes were expected for ravulizumab-treated patients following episodes of BTH, substantially reducing its ongoing management costs. Resource utilization was greater for eculizumab-treated patients than ravulizumab-treated patients due to higher incidence of BTH, and risk of elevated free C5-related BTH. Total incremental cost was substantially lower for ravulizumab- vs eculizumab-treated patients ($407 vs $9379); results were consistent when pregnant women were not included ($386 vs $3472). Conclusion: Overall resource use and costs for BTH are estimated to be lower for PNH patients receiving ravulizumab compared with eculizumab. [ABSTRACT FROM AUTHOR]