Conditions: Hypophosphatasia
Keywords: Hypophosphatasia HPP Bone Disease Soft Bones Low Alkaline Phosphatase genetic metabolic disorder alkaline phosphatase tissue-specific alkaline phosphatase (TNSALP) rickets osteomalacia
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 19
Healthy volunteers: no

Brief summary:
This clinical trial was conducted to study hypophosphatasia (HPP), a bone disorder caused by gene mutations or changes. These gene mutations cause low levels of an enzyme needed to harden bone. The purpose of this study was to test the safety and efficacy of two doses of the study drug called asfotase alfa as compared to a control group to see effects on adolescents and adults with HPP.

Detailed description:
Asfotase alfa was formerly referred to as ENB-0040

Hypophosphatasia (HPP) is a life-threatening, genetic, and ultra-rare metabolic disease characterized by defective bone mineralization and impaired phosphate and calcium regulation that can lead to progressive damage to multiple vital organs, including destruction and deformity of bones, profound muscle weakness, seizures, impaired renal function, and respiratory failure. There are limited data available on the natural course of this disease over time, particularly in patients with the juvenile-onset form.

Arms:
arm 1: Cohort 1: Daily SC injections of 0.3 mg/kg asfotase alfa (2.1 mg/kg/week total) arm 2: Cohort 2: Daily SC injections of 0.5 mg/kg asfotase alfa (3.5 mg/kg/week total) arm 3: Following completion of the Week 24 visit, all patients (including those randomized to the concurrent control cohort) may be eligible to participate in an open-label extension treatment period. In this extension period, all patients will be treated with daily SC injections of 0.5 mg/kg/day asfotase alfa (a total of 3.5 mg/kg/week) for approximately 24 weeks, then subjects will receive 1 mg/kg/day 6 days/week for an additional 48 weeks or until regulatory approval of the drug.

Interventions: intervention 1: asfotase alfa intervention 2: asfotase alfa
Intervention descriptions: intervention 1: Cohort 1: Daily SC injections of 0.3 mg/kg asfotase alfa (total of 2.1 mg/kg/week) intervention 2: Cohort 2: Daily SC injections of 0.5 mg/kg Asfotase Alfa (3.5 mg/kg/week total)

Protocol document: