Asfotase alfa

Pediatric rare diseases present unique challenges in clinical trial design and in selection of clinical outcome assessments (COAs) used to support claims in medical product labeling. COAs that discriminate level of function relative to a normative sample are particularly important in the pediatric rare disease setting because the literature is often void of natural history data. Pediatric rare disease clinical trials will often include a wide age distribution. Gross and fine motor skills, communication, cognition, and independence in activities of daily living vary by age, and it may be difficult to distinguish between treatment effect and change due to developmental maturation...

OBJECTIVES: We report a case of discordant total and free testosterone values in a patient with hypogonadism and juvenile hypophosphatasia after he initiated treatment with asfotase alfa, recombinant tissue non-specific alkaline phosphatase. METHODS: Total testosterone was evaluated using immunoassay pre and post initiation of therapy with asfotase alfa, and free testosterone was evaluated using radioimmunoassay and LC-MS/MS while on asfotase alfa therapy. RESULTS: Total testosterone measured by immunoassay was normal prior to therapy with asfotase alfa, and was low post initiation of therapy...

We report the case of a 55-year-old woman who presented to the emergency department having woken from sleep with right sided thigh swelling. Pelvic radiographs revealed bilateral atypical subtrochanteric femoral fractures (ASFFs). In the two years leading up to this admission, the patient had experienced gradually increasing pain and weakness in her legs which had resulted in a decrease in her mobility from fully mobile to bed-bound. During this time a neurologist had organised a magnetic-resonance imaging (MRI) scan of the brain and spine which was normal...

Hypophosphatasia (HPP) is the heritable metabolic disease characterized by impaired skeletal mineralization due to low activity of the tissue-nonspecific isoenzyme of alkaline phosphatase. Although HPP during growth often manifests with distinctive radiographic skeletal features, no validated method was available to quantify them, including changes over time. We created the Radiographic Global Impression of Change (RGI-C) scale to assess changes in the skeletal burden of pediatric HPP. Site-specific pairs of radiographs of newborns, infants, and children with HPP from three clinical studies of asfotase alfa, an enzyme replacement therapy for HPP, were obtained at baseline and during treatment...

We describe the clinical outcome of asfotase alfa therapy in a 16-year-old boy with severe childhood hypophosphatasia (HPP), who began therapy at age 15 years. The patient was diagnosed with HPP at age 2 years when he presented with genu varum and premature loss of primary teeth. He had a history of multiple fractures requiring 16 orthopedic surgeries with rod and pin placement in his lower extremities. He had chronic skeletal pain and used cane to ambulate with great difficulty. His height Z score at age 15 years was - 5...

Hypophosphatasia (HPP) is a rare, inherited, systemic, metabolic disorder caused by autosomal recessive mutations or a single dominant-negative mutation in the gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). The disease is associated with a broad range of signs, symptoms, and complications, including impaired skeletal mineralization, altered calcium and phosphate metabolism, recurrent fractures, pain, respiratory problems, impaired growth and mobility, premature tooth loss, developmental delay, and seizures...

PURPOSE OF REVIEW: This review highlights how skeletal dysplasias are diagnosed and how our understanding of some of these conditions has now translated to treatment options. RECENT FINDINGS: The use of multigene panels, using next-generation sequence technology, has improved our ability to quickly identify the genetic etiology, which can impact management. There are successes with the use of growth hormone in individuals with SHOX deficiencies, asfotase alfa in hypophosphatasia, and some promising data for c-type natriuretic peptide for those with achondroplasia...

Hypophosphatasia (HPP) is a rare inborn error of metabolism due to a loss-of-function mutation in the gene for tissue nonspecific isoenzyme of alkaline phosphatase (ALP) that results in low levels of ALP. The clinical presentation of HPP is variable and in adults can easily be misdiagnosed as other forms of osteomalacia. We present a case of a 53-year-old Caucasian female who was evaluated for recurrent metatarsal fractures. She reported her first metatarsal fracture at age 21, and since then had at least 8 more metatarsal fractures over her lifetime, most without injury other than weight bearing...

Hypophosphatasia (HPP) is a rare inherited disorder of bone affecting approximately 500 to 600 known individuals in the United States. HPP is the result of mutations involving the gene for tissue nonspecific alkaline phosphatase. Five clinical types of HPP are recognized. The clinical presentation of HPP varies from devastating prenatal intrauterine disease to mild manifestations in adulthood. In adults, main clinical involvement includes early loss of primary or secondary teeth, osteoporosis, bone pain, chondrocalcinosis, and fractures...

OBJECTIVE: Hypophosphatasia (HPP) is a rare skeletal disease characterized by hypomineralization and low alkaline phosphatase activity. Asfotase alfa (AA) has been recently developed to treat HPP complications. This study evaluated its safety and efficacy in Japan. DESIGN: Open-label, multicentre, prospective trial. Patients were enrolled in 11 hospitals from June 2014 to July 2015. PATIENTS: Thirteen patients (9 females, 4 males) ages 0 days to 34 years at baseline were enrolled and treated with AA (2 mg/kg three times weekly subcutaneously in all but one patient)...

Hypophosphatasia (HPP) is the inborn-error-of-metabolism that features low serum alkaline phosphatase (ALP) activity (hypophosphatasemia) caused by loss-of-function mutation(s) of the gene that encodes the tissue-nonspecific isoenzyme of ALP (TNSALP). Autosomal recessive or autosomal dominant inheritance from among >300 TNSALP (ALPL) mutations largely explains HPP's remarkably broad-ranging severity. TNSALP is a cell-surface homodimeric phosphohydrolase richly expressed in the skeleton, liver, kidney, and developing teeth...

Background. Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) of the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Consequently, cell-surface deficiency of TNSALP phosphohydrolase activity leads to extracellular accumulation of inorganic pyrophosphate, a natural substrate of TNSALP and inhibitor of mineralization. Children with HPP can manifest rickets, skeletal pain, deformity, fracture, muscle weakness, and premature deciduous tooth loss. Asfotase alfa is a recombinant, bone-targeted, human TNSALP injected s...

No abstract text is available yet for this article.

Hypophosphatasia (HPP) is a rare disease caused by loss-of-function mutations in the tissue-nonspecific alkaline phosphatase (TNAP, TNSALP) gene. HPP causes a multisystemic syndrome with a predominant bone phenotype. The clinical spectrum ranges from high lethality in early onset (<6 months) HPP to mild late-onset syndromes. HPP management so far has been only supportive. Subcutaneous asfotase alfa, a first-in-class bone-targeted human TNAP enzyme replacement therapy, is the first compound to be approved for long-term treatment of bone manifestations in pediatric-onset HPP...

Hypophosphatasia (HPP) is an inherited systemic bone disease that is characterized by bone hypomineralization. HPP is classified into six forms according to the age of onset and severity as perinatal (lethal), perinatal benign, infantile, childhood, adult, and odontohypophosphatasia. The causative gene of the disease is the ALPL gene that encodes tissue-nonspecific alkaline phosphatase (TNAP). TNAP is expressed ubiquitously, and its physiological role is apparent in bone mineralization. A defect in bone mineralization can manifest in several ways, including rickets or osteomalacia in HPP patients...

Hypophosphatasia is the inborn error of metabolism characterized by low serum alkaline phosphatase activity (hypophosphatasaemia). This biochemical hallmark reflects loss-of-function mutations within the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP is a cell-surface homodimeric phosphohydrolase that is richly expressed in the skeleton, liver, kidney and developing teeth. In hypophosphatasia, extracellular accumulation of TNSALP natural substrates includes inorganic pyrophosphate, an inhibitor of mineralization, which explains the dento-osseous and arthritic complications featuring tooth loss, rickets or osteomalacia, and calcific arthopathies...

Subcutaneous asfotase alfa (Strensiq™), a first-in-class bone-targeted human recombinant tissue-nonspecific alkaline phosphatase (TNSALP) replacement therapy, is approved in the USA for the treatment of patients with perinatal/infantile- or juvenile-onset hypophosphatasia (HPP). In clinical trials, asfotase alfa was an effective and generally well tolerated treatment for perinatal/infantile- and juvenile onset-HPP through at least 3 and 5 years' treatment, respectively. Relative to untreated age-matched, juvenile-onset-HPP historical control cohorts, survival and ventilation-free survival were significantly prolonged in asfotase alfa-treated patients, consequent to preceding improvements in bone mineralization...

CONTEXT: Hypophosphatasia (HPP) is an inborn error of metabolism that, in its most severe perinatal and infantile forms, results in 50-100% mortality, typically from respiratory complications. OBJECTIVES: Our objective was to better understand the effect of treatment with asfotase alfa, a first-in-class enzyme replacement therapy, on mortality in neonates and infants with severe HPP. DESIGN/SETTING: Data from patients with the perinatal and infantile forms of HPP in two ongoing, multicenter, multinational, open-label, phase 2 interventional studies of asfotase alfa treatment were compared with data from similar patients from a retrospective natural history study...

UNLABELLED: Hypophosphatasia (HPP) is a rare metabolic bone disease caused by loss-of-function mutations in the gene ALPL encoding the tissue nonspecific alkaline phosphatase (TNSALP). There is a broad range of severity in the phenotype of HPP, and the most severe form exhibits perinatal lethality without mineralization of the skeleton. Here, we describe a female infant with perinatal lethal HPP diagnosed in utero. She was treated with a recombinant ALP (asfotase alfa) as an enzyme replacement therapy (ERT), which started from 1 day after birth...

Hypophosphatasia (HPP) is an inborn-error-of-metabolism disorder characterized by deficient bone and tooth mineralization due to loss-of function mutations in the gene (Alpl) encoding tissue-nonspecific alkaline phosphatase (TNAP). Alpl(-/-) mice exhibit many characteristics seen in infantile HPP including long bone and tooth defects, vitamin B6 responsive seizures and craniosynostosis. Previous reports demonstrated that a mineral-targeted form of TNAP rescues long bone, vertebral and tooth mineralization defects in Alpl(-/-) mice...