A Phase 3b Open-label Study of the Anti-FGF23 Antibody, Burosumab (KRN23) in Adult Patients with X-linked Hypophosphatemia (XLH)

Phase 1

• Conditions: XLH is a rare, genetic disorder that is serious, chronically debilitating and represents an unmet medical need. This genetic deficiency is estimated to occur in about 1:20,000 live births (Burnett et al. 1964), (Imel et al. 2005). XLH is the most common inherited form of rickets and the most common inherited defect in renal tubular phosphate transport. XLH is transmitted as an X-linked dominant disorder (Dixon et al. 1998).; MedDRA version: 20.0 Level: LLT Classification code 10016206 Term: Familial hypophosphataemic rickets System Organ Class: 100000004850; Therapeutic area: Body processes [G] - Bones and nerves physological processes [G11]

• Registration Number: EUCTR2018-000202-37-FR
• Lead Sponsor: Kyowa Kirin Pharmaceutical Development Ltd

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2018-08-31
• Last Update Posted: 30 April 2019

Recruitment & Eligibility

• Status: Authorised-recruitment may be ongoing or finished
• Sex: Not specified
• Target Recruitment: 40

Inclusion Criteria

1) Subjects who provide written informed consent after the nature of the study has been
explained, and prior to any research-related procedures.
2) Subjects who successfully completed Study UX023-CL303 or UX023-CL304. Subjects
should have completed the study up to and including the final study visit. Subjects who were
prematurely discontinued due to adverse events, Sponsor’s decision or Investigator’s decision
will not be enrolled in this study. Subjects’ enrolment is not dependent on any response to
Primary or Secondary endpoints in studies UX023-CL303 or UX023-CL304.
3) Willing to provide access to prior medical records for the collection of historical growth,
biochemical and radiographic data, and disease history.
4) Must, in the opinion of the investigator, be willing and able to complete all aspects of the
study, adhere to the study visit schedule and comply with the assessments.
5) Females of child-bearing potential must have a negative urine pregnancy test at Screening and
be willing to have additional pregnancy tests during the study. Females considered not to be of
child-bearing potential include those who have been in menopause for at least two years prior
to Screening, or have had tubal ligation at least one year prior to Screening, or have had a total
hysterectomy or bilateral salpingo-oophorectomy. If sexually active, male and female subjects
must be willing to use one highly effective method of contraception for the duration of the
study.
Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 40
F.1.3 Elderly (>=65 years) yes
F.1.3.1 Number of subjects for this age range 10

Exclusion Criteria

1) Hypocalcemia or hypercalcemia, defined as serum calcium levels outside the age-adjusted
normal limits and deemed as clinically significant in the opinion of the investigator.
2) Presence of a concurrent disease or condition that would interfere with study participation
or affect safety in the opinion of the investigator or Sponsor.
3) Use of any investigational product other than burosumab or investigational medical device
within 30 days prior to Screening, or requirement for any investigational agent prior to
completion of all scheduled study assessments.
4) Subjects with major protocol deviations in Study UX023-CL303 or UX023-CL304 which
in the view of the investigator places the subject at high risk of poor treatment compliance or
of not completing the study.

Study & Design

• Study Type: Interventional clinical trial of medicinal product
• Study Design: Not specified