Taichi Kitaoka1, Toshihiro Tajima2, Keisuke Nagasaki3, Toru Kikuchi3, Katsusuke Yamamoto4, Toshimi Michigami5, Satoshi Okada6, Ikuma Fujiwara7, Masayuki Kokaji8, Hiroshi Mochizuki9, Tsutomu Ogata10, Koji Tatebayashi11, Atsushi Watanabe12, Shuichi Yatsuga13, Takuo Kubota1, Keiichi Ozono1. 1. Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan. 2. Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan. 3. Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. 4. Department of Pediatric Nephrology and Metabolism, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan. 5. Department of Bone and Mineral Research, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan. 6. Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan. 7. Department of Pediatrics, Tohoku University School of Medicine, Miyagi, Japan. 8. Department of Pediatrics, Showa General Hospital, Tokyo, Japan. 9. Division of Endocrinology and Metabolism, Saitama Children's Medical Center, Saitama, Japan. 10. Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan. 11. Department of Pediatrics, Nagara Medical Center, Gifu, Japan. 12. Division of Clinical Genetics, Nippon Medical School Hospital, Tokyo, Japan. 13. Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan.
Abstract
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). All had ALPL gene mutations. HPP forms were perinatal (n=6), infantile (n=5), childhood (n=1) and adult (n=1). MEASUREMENTS: Safety determined from adverse events (AEs) and laboratory data was the primary outcome measure. Efficacy was assessed as a secondary outcome measure from overall survival, respiratory status, rickets severity and gross motor development. RESULTS: Injection site reactions were the most frequent AEs. Serious AEs possibly related to treatment were convulsion and hypocalcaemia observed in a patient with the perinatal form. In addition, hypercalcaemia and/or hyperphosphatemia was observed in three patients with the infantile form and a low-calcium and/or low-phosphate formula was given to these patients. With respect to efficacy, all patients survived and the radiographic findings, developmental milestones and respiratory function improved. CONCLUSION: Asfotase alfa therapy improved skeletal, respiratory and physical symptoms with a few serious AEs in patients with HPP. Our results add support to the safety and efficacy of AA therapy for HPP patients.
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). All had ALPL gene mutations. HPP forms were perinatal (n=6), infantile (n=5), childhood (n=1) and adult (n=1). MEASUREMENTS: Safety determined from adverse events (AEs) and laboratory data was the primary outcome measure. Efficacy was assessed as a secondary outcome measure from overall survival, respiratory status, rickets severity and gross motor development. RESULTS: Injection site reactions were the most frequent AEs. Serious AEs possibly related to treatment were convulsion and hypocalcaemia observed in a patient with the perinatal form. In addition, hypercalcaemia and/or hyperphosphatemia was observed in three patients with the infantile form and a low-calcium and/or low-phosphate formula was given to these patients. With respect to efficacy, all patients survived and the radiographic findings, developmental milestones and respiratory function improved. CONCLUSION: Asfotase alfa therapy improved skeletal, respiratory and physical symptoms with a few serious AEs in patients with HPP. Our results add support to the safety and efficacy of AA therapy for HPP patients.