A Study of KRN23 in Adult and Pediatric Patients With X-linked Hypophosphatemic Rickets/Osteomalacia

Inclusion criteria

• Personally submitted voluntary written informed consent to participate in the study; For pediatric patients, personally submitted voluntary written informed consent by a legally authorized representative.

If appropriate, written or verbal assent to participate in the study should be obtained from patients.

• Patients meeting any of the followings;

• For adult XLH patients, completion the final observation at Week 96 in UX023-CL303 or UX023-CL304
• For pediatric patients, completion the final observation at Week 64 in UX023-CL301
• For female patients; women of childbearing potential (except for females who have not reached menarche, permanently sterilized, postmenopausal [12 months with no menses without an alternative medical cause] or anatomically not of childbearing potential) with negative pregnancy test at pre-treatment assessment of Week 0
• For female patient with childbearing potential, or male patients with reproductive capacity; willingness to use acceptable methods of contraception while participating in the study
• Willingness and ability to cooperatively complete all study procedures, adhere to the visit schedule and follow the investigator's instructions, as considered by investigator or subinvestigator

Exclusion criteria

• Use of oral phosphate for treating XLH, pharmacologic vitamin D metabolites or analogs, aluminum hydroxide antacids, systemic corticosteroids, acetazolamide, and thiazides within 7 days prior to scheduled initial administration of investigational drug
• Planned or recommended orthopedic surgery (implantation or removal), including staples, 8 plates or osteotomy, during the study period
• Blood or blood product transfusion within 60 days prior to scheduled initial administration of investigational drug
• Use of growth hormone therapy within 12 months prior to scheduled initial administration of investigational drug
• Use of medication to suppress the secretion of parathyroid hormone (e.g., cinacalcet) within 60 days prior to scheduled initial administration of investigational drug
• Use of any investigational product (except for investigational product of the preceding study) or investigational medical device within 4 months prior to scheduled initial administration of investigational drug, or requirement for any investigational agent prior to completion of all scheduled study assessments
• Use of a therapeutic monoclonal antibody other than KRN23 within 90 days prior to scheduled initial administration of investigational drug
• History of being positive for HIV antibody, HBs antigen and/or HCV antibody
• Anyone otherwise considered unsuitable for the study by the investigator or subinvestigator

At the time of switching to the post-marketing clinical study:

Subjects eligible for enrollment in the post-marketing clinical study must have met both of the following criteria:

• Personally submitted voluntary written informed consent to participate in the postmarketing clinical study. For pediatric patients, personally submitted voluntary written informed consent by a legally authorized representative. If appropriate, written or verbal assent to participate in the post-marketing clinical study was to be obtained from subjects.
• Switching to the post-marketing clinical study was necessary and appropriate for the subject from the viewpoint of efficacy and safety, as judged by the investigator or subinvestigator