Analysis of caregiver perspectives on patients with mucopolysaccharidosis II treated with pabinafusp alfa: results of qualitative interviews in Japan

• Published in: Orphanet journal of rare diseases Vol. 19; no. 1; p. 104
• Main Authors: Nakamura, Kimitoshi, Sakai, Norio, Hossain, Mohammad Arif, Eisengart, Julie B, Yamamoto, Tatsuyoshi, Tanizawa, Kazunori, So, Sairei, Schmidt, Mathias, Sato, Yuji
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 07.03.2024; BioMed Central; BMC
• Subjects: Analysis; Beliefs, opinions and attitudes; Blood-brain barrier; Care and treatment; Caregiver-reported outcomes; Caregivers; Caregivers - psychology; Child; Clinical trials; Cognitive ability; Confidentiality; Diagnosis; Enzyme Replacement Therapy - methods; Enzymes; Families & family life; Forecasts and trends; Genetic disorders; Health aspects; Heparan sulfate; Humans; Hunter syndrome; Iduronate Sulfatase - therapeutic use; Infections; Japan; Male; Metabolic disorders; Mobility; Mucopolysaccharidosis; Mucopolysaccharidosis II - drug therapy; Mucopolysaccharidosis type II; Pabinafusp alfa; Patients; Qualitative research; Quality of Life; Rare Diseases - drug therapy; Sleep; Treatment experience; Japan; Mucopolysaccharidosis type II; Treatment experience; Hunter syndrome; Caregiver-reported outcomes; Pabinafusp alfa; Qualitative caregiver interviews; Quality of life
• ISSN: 1750-1172; 1750-1172
• DOI: 10.1186/s13023-024-03112-1

Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a rare X-linked metabolic disorder predominantly affecting males. Pabinafusp alfa, an iduronate-2-sulfatase enzyme designed to cross the blood-brain barrier, was approved in Japan in 2021 as the first enzyme replacement therapy targeting both the neuropathic and somatic signs and symptoms of MPS II. This study reports caregivers' experiences of MPS II patients receiving pabinafusp alfa through qualitative interviews. Semi-structured, qualitative interviews were conducted with caregivers at seven clinical sites in Japan using a semi-structured moderation guide (Voice of the Caregiver guide). Thematic analysis was applied to the interview transcripts to identify symptoms and health-related quality of life impacts at baseline, changes during treatment, and overall treatment experience. Seven caregivers from 16 trial sites participated, representing seven children aged 8-18 years who had received pabinafusp alfa for 3.3-3.5 years at the time of the interviews. Data suggest a general trend toward improvement in multiple aspects, although not all caregivers observed discernible changes. Reported cognitive improvements included language skills, concentration, self-control, eye contact, mental clarity, concept understanding, following instructions, and expressing personal needs. Further changes were reported that included musculoskeletal improvements and such somatic changes as motor function, mobility, organ involvement, joint mobility, sleep patterns, and fatigue. Four caregivers reported improvements in family quality of life, five expressed treatment satisfaction, and all seven indicated a strong willingness to continue treatment of their children with pabinafusp alfa. Caregivers' perspectives in this study demonstrate treatment satisfaction and improvement in various aspects of quality of life following therapy with pabinafusp alfa. These findings enhance understanding of pabinafusp alfa's potential benefits in treating MPS II and contribute to defining MPS II-specific outcome measures for future clinical trials.