Quality of Life in Adults with Hypophosphatasia: Results from a Multicountry Survey

Presentation Number: MON 337
Date of Presentation: April 3rd, 2017

Ioanna Parthenaki1, Judith Balvanyos1, Gráinne Crowley2 and Ioannis C. Tomazos*3
1Dolon Limited, London, United Kingdom, 2Alexion Pharmaceuticals, Inc. *at time of study, New Haven, CT, 3Alexion Pharmaceuticals, Inc., New Haven, CT


Hypophosphatasia (HPP) is a rare disease caused by loss-of-function mutations in the gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). Deficient TNSALP activity leads to a spectrum of symptoms; in adults, this includes recurrent/poorly healing fractures, altered ambulation, and joint, bone, and muscle pain. The impact of HPP on health-related quality of life (HRQOL) is poorly described in the literature. To assess burden of HPP on HRQOL in children, adults, and caregivers, Alexion Pharmaceuticals, Inc., developed an online and mail questionnaire in collaboration with physicians and patient (pt) associations; responses were solicited from pts and their families from April to May 2015. Questions focused on HPP disease symptoms and impact of HPP on physical function, emotional well-being, employment, activities of daily living, and hospitalization. Five questions were derived from the EuroQol 5 Dimensions (EQ-5D) questionnaire; responses were converted to time trade-off (TTO) and visual analog scale (VAS) scores. Results from adult participants are reported. In all, 27 adults from the United Kingdom, Germany, France, and Switzerland completed the questionnaire (median age [range]: 51 [18–72] years; female: 81% [22/27]). Mean overall EQ-5D scores were low (TTO: 0.36; VAS: 0.43), with the worst scores (TTO: −0.01; VAS: 0.23) reported by pts relying on mobility aids (e.g., wheelchair) most of the time (n=5). All pts reported pain, fatigue, and mobility impairments. Pain was moderate in 63% (17/27) of pts and extreme in 37% (10/27); 78% (21/27) reported daily pain, and 48% (13/27) rated it extremely burdensome. Mean fatigue score was 6.9 (scale: 0 [no fatigue] to 10 [severe fatigue]). Majority of pts (78%; 21/27) had walking limitations; 59% (16/27) reported walking on their own but for a limited distance, and 19% (5/27) relied on a walking aid most of the time. Anxiety or depression was reported by 73% (19/26) of pts. Mean satisfaction score was 5.8 for life, 7.2 for family life, and 5.9 for social life (scale: 0 [not satisfied] to 10 [very satisfied]). In all, 15% (4/27) of pts reported family life dissatisfaction and 33% (9/27) reported social life dissatisfaction; 22% (6/27) and 26% (7/27) were neither satisfied nor dissatisfied with family life and social life, respectively. Of the 42% (11/26) of pts who were employed, 45% (5/11) felt that HPP had significantly impacted their work efficiency. Most pts (77% [20/26]) reported problems performing daily life activities. Hospitalization rates were higher for pts who relied on a walking aid most of the time vs pts able to walk on their own but for a limited distance and pts able to walk as far as any other same-age adult. Results of this pt-reported questionnaire demonstrate that HPP causes a substantial impact on HRQOL in adult pts, including effect on function and mobility, fatigue, pain, emotional status, employment, and daily living.


Disclosure: IP: Research Funding, Alexion Pharmaceuticals, Inc.. JB: Research Funding, Alexion Pharmaceuticals, Inc.. GC: Employee, Alexion Pharmaceuticals, Inc. *at time of study. ICT: Employee, Alexion Pharmaceuticals, Inc..