OBJECTIVES: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by hemolysis and thrombosis, and often leads to anemia. In Canada, a hemoglobin (Hb) threshold of ≤10g/dL is required to access or to switch between PNH therapies. This research aims to describe the burden of PNH patients with Hb ≥10 to <12 g/dL, treated with complement 5 inhibitors (C5i) in Canada.

METHODS: Data were collected from Adelphi PNH Disease Specific Programme™, a cross-sectional survey of physicians and their patients living with PNH in Canada (January–November 2022). Physicians reported data for consecutively consulting patients, including sociodemographics, blood transfusions, hospitalizations, and impact of PNH on quality of life (QoL). Patients prescribed C5i with Hb ≥10 to <12 g/dL were included in this analysis. Descriptive statistics were reported, missing data were not imputed.

RESULTS: Four physicians reported data for 19 patients treated with C5i, for a mean (SD) duration of 2.5 (3.3) years. The mean (SD) patient age was 51.9 (15.7) years and 68% were male. All surveyed patients were symptomatic and 10% were not working due to PNH. Overall, 63% of patients required a blood transfusion in the 12 months prior to survey. Mean (SD) number of transfusions was 1.4 (1.4), with an average 2.2 units of blood received at their most recent transfusion. A total of 12% of patients were hospitalized due to severe fatigue or infection. Importantly, patients were unable to carry out daily activities, with 39% of patients had avoided physical activities, vacations (11%) and social events (11%) due to their PNH.

CONCLUSIONS: These findings suggest that an unmet need exists for PNH patients treated with C5i in Canada. Patients still experienced transfusions, hospitalizations, and impaired QoL. Restricting access criteria based on Hb threshold ≤10g/dL may hinder canadian patients who are inadequately controlled on C5i to switch to alternative treatments options.