Work Productivity Loss and Quality of Life in Paroxysmal Nocturnal Hemoglobinuria Among Patients Receiving C5 Inhibitors in the United States

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, hematologic disease characterized by chronic complement-mediated hemolysis. Treatment with the C5 inhibitor eculizumab has resulted in a reduction in intravascular hemolysis and improvements in morbidity and mortality. Even with the clinical benefit in PNH, eculizumab entails twice-monthly intravenous infusions in a hospital setting in most countries, adversely impacting patients' work productivity (Mastellos DC, et al.Semin Hematol. 2018;55(3):167-175). Lost productivity associated with eculizumab ranged from $344,000 in Russia to $4.3 million in the United States, without caregivers (Levy AR, et al.Blood. 2019;134(Supplement_1):4803). Furthermore, patients in a real-world study treated with eculizumab for 1 year experienced continued impairment in overall quality-of-life relative-to-normative reference scores for the general adult population (Ueda Y, et al.Int J Hematol. 2018;107(6):656-665). This study aims to understand the clinical, humanistic, and economic outcomes associated with burden of illness in about 150 patients with PNH globally. In these preliminary analyses, productivity loss and quality of life (QoL) in patients with PNH currently being treated with C5 inhibitors (eculizumab and ravulizumab) are assessed in patients in the United States.

METHODS

This cross-sectional survey administered to adult patients in the United States, ≥18 years of age, with self-reported diagnosis of PNH, was initiated in July 2020 and is ongoing. Patients were recruited through a patient advocacy group. Inclusion criteria to complete the secure online survey include current treatment with either eculizumab or ravulizumab, and agreement to provide informed consent and adverse event reporting. To investigate the impact of PNH on employment and activity, the Work Productivity and Activity Impairment-General Health (WPAI-GH) questionnaire was used. QoL was assessed using Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). For the preliminary WPAI-GH analysis presented here, descriptive statistics are reported for patients who have completed the survey thus far. Analyses examining the impact of PNH on FACIT-Fatigue, EORTC QLQ-C30, and other clinical outcomes assessments among patients on anti-C5 therapy are ongoing.

RESULTS

A total of 58 adult patients completed the survey as of August 6, 2020. Patients' median age was 52 years (range, 21-88) and 78% of patients were female. Twenty patients (34%) were on eculizumab and 38 (66%) were on ravulizumab. Most patients (93%) had initiated treatment ≥3 months prior to enrollment. In total, 23 (40%) patients reported that they were gainfully employed. Overall, 52% of employed patients reported missing hours of work in the prior 7 days due to their health problems (67% eculizumab and 43% ravulizumab). About 77% of working patients reported that their illness affected their productivity at work (89% eculizumab and 69% ravulizumab) due to the same reason. Employed patients reported an average of 13% (standard deviation, 21%) absenteeism (ie, work time lost due to being absent for illness in the previous week; eculizumab, 22% ± 29%, ravulizumab, 7% ± 12%). Patients reported 26 ± 27% impairment while working over the past 7 days (ie, presenteeism; eculizumab, 39 ± 31%, ravulizumab, 18 ± 22%). Total work productivity impairment was on average 32 ± 31% (eculizumab, 46 ± 35%; ravulizumab, 23 ± 24%). Nearly all patients (n = 54 [93%]) reported at least some impairment in their usual activities regardless of employment (eculizumab, 100%; ravulizumab, 90%). On average, patients reported 38 ± 23% of impaired activity in the previous week (eculizumab, 43 ± 20%; ravulizumab, 36 ± 25%).

CONCLUSIONS

Preliminary results from this burden of illness survey evaluating humanistic and economic outcomes in patients with PNH demonstrated substantial loss of work-related productivity, greatly diminished ability to work, and limitations in patients' usual activities while being treated with the C5 inhibitors eculizumab and ravulizumab.