Hypophosphatasia : presentation and response to asfotase alfa

© 2023. International Osteoporosis Foundation and Bone Health and Osteoporosis Foundation..

Hypophosphatasia (HPP) is a rare bone disease with limited scientific evidence on the tolerability and safety of its novel treatment, Asfotase Alfa (AA). We report 7 HPP patients' heterogenous presentations and the significant improvement in various clinical outcomes attained with AA shedding light on this highly effective and safe therapy.

INTRODUCTION: Hypophosphatasia (HPP) is a rare inherited metabolic bone disorder characterized by a deficiency in the tissue non-specific alkaline phosphatase (TNSALP) due to loss of function mutation in the ALPL gene. HPP is associated with impaired skeletal mineralization due to elevations in inorganic pyrophosphate and altered phosphate : pyrophosphate ratio. Asfotase alfa (AA) "enzyme replacement" was approved for treatment of HPP in 2015. We present 7 patients with HPP, 5 with pediatric-onset, and 2 with adult-onset, who have been treated with AA and describe the efficacy and safety in these patients.

METHODS: 7 patients (4 females, 3 males) aged 19-68 years with HPP were included in this study. Diagnosis of HPP was confirmed by DNA analysis. AA was administered in doses of 6mg/kg/week with a mean follow-up of 6 months (SD= 5).

RESULTS: Subjective improvement in muscle strength, muscle pain, walking ability, and walking distance with a reduction in the use of gait aids was seen "with AA in HPP patients." Muscle strength and pain improved by up to 70% from baseline as quantified subjectively by patients. Walking distance improved by up to 100%. Patients also reported improved cognition, mood, and energy levels, with up to 90% improvement in mood and 75% improvement in energy levels. 4 out of 6 patients first noted clinical signs of improvement after 3 months of being on therapy. 1 out of the 7 patients sustained a toe fracture 10 months from being on AA. AA was well-tolerated with injection site reactions being the most reported adverse effect.

CONCLUSION: HPP treatment with AA in individuals with both pediatric and adult-onset forms resulted in significant subjective improvement in musculoskeletal and cognitive manifestations in addition to patients' quality of life. The drug was well tolerated in 6 patients. 1 patient discontinued therapy because of minor adverse effects with myalgias.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:35

Enthalten in:

Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA - 35(2024), 4 vom: 31. März, Seite 717-725

Sprache:

Englisch

Beteiligte Personen:

Alsarraf, F [VerfasserIn]
Ali, D S [VerfasserIn]
Almonaei, K [VerfasserIn]
Al-Alwani, H [VerfasserIn]
Khan, A A [VerfasserIn]
Brandi, M L [VerfasserIn]

Links:

Volltext

Themen:

Alkaline Phosphatase
Asfotase alfa
Diphosphates
EC 3.1.3.1
Hypophosphatasia
Immunoglobulin G
Journal Article
Presentation
Recombinant Fusion Proteins
Treatment
Z633861EIM

Anmerkungen:

Date Completed 22.03.2024

Date Revised 22.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00198-023-06943-z

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364849576