Health-Related Quality of Life, Work Productivity and Activity Impairment, and Fatigue in Patients with Idiopathic or Lymphocytic Hypereosinophilic Syndrome: A Real-World Survey

Introduction: Hypereosinophilic syndrome (HES) is a group of rare diseases characterized by persistent hypereosinophilia in the blood and/or tissues, conferring significant disease burden. This real-world study described the impact of idiopathic HES (I-HES) and lymphocytic HES (L-HES) on the health-related quality of life (HRQoL), impairment to work and activity, and fatigue of patients (pt)s. Methods: Data were drawn from the Adelphi Real World HES Disease Specific Programme™, a cross-sectional survey of physicians and pts in France, Germany, Italy, Spain, the United Kingdom (UK), and the United States from July-December 2023. Physicians reported pt demographics, clinical and disease characteristics (disease severity and status were physician determined) and treatment patterns for two to four consecutively consulting pts with I-HES or L-HES whom they were managing. Pts reported HRQoL using the EQ-5D-5L (Dolan 1997 UK tariff; index score ranging from 0 [worst health] to 1 [best health]), the Work Productivity and Activity Impairment questionnaire (WPAI; 0 [no impairment] to 100 [maximum impairment]), and the Pt Reported Outcome Measurement Information System Fatigue 7a (PROMIS-Fatigue 7a; 29.4 [lowest level of fatigue] to 83.2 [highest level of fatigue]). Analyses were descriptive. Results: Overall, 117 physicians provided data on 451 pts with I-HES or L-HES with a mean (standard deviation [SD]) age of 44.7 (16.1) years, of whom 62% were male. Of pts who provided their ethnicity (n=367), 87% were White. In pts who completed EQ-5D (n=123), WPAI (n=60), and PROMIS-Fatigue 7a (n=122) questionnaires, mean (SD) ages were 38.7 (14.0), 39.1 (10.3) and 38.7 (14.2) years, respectively. Around two-thirds (≥65%) of pts who completed these questionnaires were male, and most (≥98%) were White. All outcome scores are presented as mean (SD). Overall, EQ-5D was 0.80 (0.14). In pts with severe (n=3), moderate (n=25), mild (n=65) and inactive (n=30) HES, EQ-5D were 0.54 (0.10), 0.69 (0.11), 0.80 (0.13) and 0.90 (0.10), respectively. In pts with deteriorating (n=7), stable (n=53), or improving HES (n=62), EQ-5D were 0.61 (0.09), 0.80 (0.14) and 0.82 (0.14), respectively. EQ-5D in pts with a most recent peak blood eosinophil (bEOS) count of <500 (n=43), 500-999 (n=17) and >1000 cells/μL (n=20) were 0.81 (0.13), 0.70 (0.09) and 0.77 (0.15), respectively. In pts experiencing 0 (n=21), 1-2 (n=29), or ≥3 (n=73) symptoms at survey completion, EQ-5D were 0.92 (0.11), 0.84 (0.11) and 0.75 (0.14), respectively. The signs and symptoms (EQ-5D) of I-HES and L-HES with an EQ-5D of ≤0.65 that impacted ≥5 pts were: night sweats (0.59 [0.04]), weight loss (0.61 [0.10]), restrictive cardiomyopathy (0.61 [0.16]), nausea (0.64 [0.15]), diarrhea (0.65 [0.13]), and malaise (0.65 [0.18]). In pts with (n=73) and without (n=39) organ damage, respectively, that was caused by I-HES or L-HES as captured through available medical records, EQ-5D were 0.77 (0.14) and 0.85 (0.13). EQ-5D in pts with cardiovascular organ damage (n=16) was 0.70 (0.15). In pts with EQ-5D (n=123), the proportion of pts receiving treatment by treatment type were: glucocorticoids (GC; 67%), biologics (30%), immunosuppressants (7%) and other treatments (17%); three pts were not receiving any treatment. In pts receiving GC doses (prednisolone equivalent) of 0 (n=53), 1-<10 (n=34) or ≥10 (n=36) mg/day, EQ-5D were 0.82 (0.14), 0.82 (0.13) and 0.75 (0.15), respectively. EQ-5D in pts who did (n=32) and did not (n=91) need additional caregiver support were 0.73 (0.15) and 0.82 (0.13), respectively. Overall, WPAI was 19.8 (19.6) and PROMIS-Fatigue 7a was 49.0 (8.8). WPAI in pts with severe (n=2), moderate (n=12), mild (n=34) and inactive (n=12) disease, respectively, were 35.0 (7.1), 28.0 (24.9), 19.9 (17.9) and 8.8 (14.5). PROMIS-Fatigue 7a in pts with severe (n=3), moderate (n=24), mild (n=64) and inactive (n=31) disease, respectively, were 57.1 (19.8), 53.2 (8.2), 48.9 (8.0) and 45.4 (8.0). Conclusion: Real-world evidence from physicians and pts illustrated I-HES and L-HES have a negative impact on HRQoL, work and activity impairment and fatigue, especially in pts with moderate or severe disease. HRQoL was also notably impacted in pts with high bEOS counts, more symptoms and those needing caregiver support. Provision of better targeted therapies during earlier stages of the pt journey could address the need to alleviate the burden experienced by pts with I-HES and L-HES.