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Study of the Anti-FGF23 Antibody, Burosumab, in Adults With XLH

Primary Purpose

X-linked Hypophosphatemia

Status
Completed
Phase
Phase 3
Locations
International
Study Type
Interventional
Intervention
Burosumab
Sponsored by
Kyowa Kirin Pharmaceutical Development Ltd
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for X-linked Hypophosphatemia focused on measuring Crysvita, Burosumab, X-linked Hypophosphatemia (XLH), PHEX Gene Mutation, PHEXdb

Eligibility Criteria

18 Years - 70 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

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 participated in Study UX023-CL303 or UX023-CL304. Any subjects that did not complete Study UX023-CL303 or UX023-CL304 may be included on a case-by-case basis. 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.

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.
  5. Subjects who discontinued treatment from Study UX023-CL303 or UX023-CL304 due to either a grade ≥3 treatment-related hypersensitivity reaction or a burosumab-related hypersensitivity reaction reported as a SAE.

Sites / Locations

  • CHU de Bicetre
  • Hopital Lariboisiere
  • Hopital Cochin
  • St. Vincent's University Hospital
  • Azienda ospedaliera universitaria Careggi
  • Western General Hospital
  • National Hospital for Neurology and Neurosurgery-University College London Hospitals NHS Foundation Trust
  • Nuffield Orthopaedic Centre - Oxford University Hospitals Nhs Trust
  • Northen General Hospital
  • Royal National Orthopaedic Hospital NHS Trust

Arms of the Study

Arm 1

Arm Type

Other

Arm Label

Open label

Arm Description

All subjects will be administered subcutaneously burosumab every 4 weeks at the dosage defined in study UX023-CL303 or UX023-CL304 until December 2021 or when the drug becomes commercially available.

Outcomes

Primary Outcome Measures

Proportion of subjects achieving mean serum phosphorus levels above the LLN (2.5mg/dL[0.81mmol/L]), as averaged across dose cycles between baseline and their last administered dose.
To establish the effect of burosumab treatment on maintaining serum phosphorus levels to within normal range in adults with XLH.

Secondary Outcome Measures

Effect of burosumab on pre-existing pseudofracture healing will be monitored by centrally read targeted X-Ray
Targeted radiography at locations pre-determined by the skeletal survey performed during UX023-CL303 or UX023-CL304 will be taken to monitor healing of pseudofractures and/or fractures.
Effect of burosumab on patients walking ability measured using the 6 Minute Walk Test.
Patient's motor function by sustained walking will be evaluated using the 6 Minute Walk Test. (6MWT). The percent predicted values for the 6MWT will be calculated using published normative data based on age, gender and height.
Effect of burosumab on Patient mobility assessed using the Timed Up and Go Test (TUG).
The TUG assesses transitions during ambulatory activity incorporating strength, agility and dynamic balance assessments. The TUG score will be reported as the time (in seconds) that a subject takes to rise from a chair, walk three meters (approximately 10 feet), turn around, walk back to the chair and sit down.
Effect of burosumab on stiffness and physical function will be assessed using WOMAC.
The patient's impression of their stiffness and physical function will be assessed by administering the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire- a 24 item patient reported questionnaire. The WOMAC will be administered in a 5-point Likert-scale format using descriptors of none, mild, moderate, severe and extreme corresponding to an ordinal scale of 0 to 4. Higher scores on the WOMAC indicate worse stiffness and functional limitations.
Effect of burosumab on patient's pain severity and the impact of pain on functioning will be assessed using the Short-form Brief Pain Inventory questionnaire.
The patient's recall of pain over a 24 hour period will be captured by administering the short form of the Brief Pain Inventory (BPI) questionnaire. The BPI evaluates the condition of all pain over the previous 24 hours. Two dimensions are measured: pain severity (worst, least, average and now) and the impact of pain on functioning (pain interference with general activity, walking, work, mood, enjoyment of life, relations with others and sleep).
Effect of burosumab on patient's fatigue and the interference of fatigue on daily life over a 24 hour period.
The patient's recall of fatigue will be captured by administering the Brief Fatigue Inventory (BFI) questionnaire. The BFI is a self-reported questionnaire consisting of nine items related to fatigue that are rated on a 0 to 10 numerical rating scale with a recall period of 24 hours. Two dimensions are measured: fatigue and the interference of fatigue on daily life. The change from baseline to post-baseline visits will be assessed.
Effect of burosumab on bone metabolism and phosphate homeostasis using urinary phosphorus as PD marker.
Pharmacodynamic assessment.
Effect of burosumab on enthesopathy will be monitored by centrally read targeted X-Ray.
Lateral foot views (bilateral) will be obtained in all subjects at Screening (as part of skeletal survey) and at End of Study (EOS). Size of enthesopathy spurs at both the superior and inferior calcaneus will be measured in two dimensions.
Effect of burosumab on bone metabolism and phosphate homeostasis using Serum Phosphorus as PD marker.
Pharmacodynamic assessment.
Effect of burosumab on bone metabolism and phosphate homeostasis using serum 1, 25(OH)2D as PD marker.
Pharmacodynamic assessment.
Effect of Burosumab on phosphate reabsorption as measured by the ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtrate [TmP/GFR].
Pharmacodynamic assessment.
Effect of burosumab on health related quality of life as measured by SF-36v2
Patients will answer questions around their physical functioning, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health

Full Information

First Posted
October 29, 2018
Last Updated
May 19, 2022
Sponsor
Kyowa Kirin Pharmaceutical Development Ltd
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1. Study Identification

Unique Protocol Identification Number
NCT03920072
Brief Title
Study of the Anti-FGF23 Antibody, Burosumab, in Adults With XLH
Official Title
A Phase 3b Open-label Study of the Anti-FGF23 Antibody, Burosumab (KRN23) in Adult Patients With X-linked Hypophosphatemia (XLH)
Study Type
Interventional

2. Study Status

Record Verification Date
May 2022
Overall Recruitment Status
Completed
Study Start Date
March 7, 2019 (Actual)
Primary Completion Date
April 7, 2022 (Actual)
Study Completion Date
April 7, 2022 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Kyowa Kirin Pharmaceutical Development Ltd

4. Oversight

Studies a U.S. FDA-regulated Drug Product
Yes
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
This is phase 3b open-label, international, multicenter study to continue to monitor the long-term safety and efficacy of burosumab in adult patients with XLH that participated in previous clinical trials with burosumab (UX023-CL303 / UX023-CL304).
Detailed Description
XLH is a rare, genetic disorder that is serious, chronically debilitating and represents an unmet medical need. 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. Mutations resulting in the loss of function of PHEX form the genetic basis for XLH. More than 300 different PHEX gene mutations have been identified in patients with XLH (PHEXdb); however, few definitive correlations have been observed between specific mutations and phenotypic severity. Patients with XLH have hypophosphatemia due to excessive serum FGF23 levels. FGF23 reduces serum phosphorus levels by two distinct mechanisms of action. The primary mechanism is to inhibit phosphate reabsorption in the proximal tubule of the kidney. The secondary mechanism is to decrease phosphate absorption by the small intestine through the inhibition of 1,25(OH)2D production in the kidney. Burosumab has the potential to block or reduce FGF23 action and improve phosphate homeostasis in XLH patients. Burosumab binds the amino-terminal domain of FGF23 that interacts with the FGF-binding portion of the combination FGFR1/Klotho receptor, preventing FGF23 from binding to and signaling from its receptor. Both intact and fragmented FGF23 polypeptides are immunoprecipitated with burosumab. By inhibiting FGF23, burosumab restores tubular reabsorption of phosphate (as measured by the ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtration rate [TmP/GFR]) from the kidney and increases the production of 1,25(OH)2D that also enhances intestinal absorption of phosphate. The dual action on kidney reabsorption and intestinal absorption improves serum phosphorus levels, which is expected to improve bone mineralization and reduce the diverse bone and non-bone manifestations associated with hypophosphatemia in XLH patients.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
X-linked Hypophosphatemia
Keywords
Crysvita, Burosumab, X-linked Hypophosphatemia (XLH), PHEX Gene Mutation, PHEXdb

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Single Group Assignment
Model Description
Open-label, international, multicenter
Masking
None (Open Label)
Allocation
N/A
Enrollment
35 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Open label
Arm Type
Other
Arm Description
All subjects will be administered subcutaneously burosumab every 4 weeks at the dosage defined in study UX023-CL303 or UX023-CL304 until December 2021 or when the drug becomes commercially available.
Intervention Type
Drug
Intervention Name(s)
Burosumab
Other Intervention Name(s)
KRN23, Crysvita
Intervention Description
Burosumab is a sterile, clear, colourless and preservative free solution supplied in single-use 5ml vials containing 1mL of burosumab at a concentration of 30mg/mL
Primary Outcome Measure Information:
Title
Proportion of subjects achieving mean serum phosphorus levels above the LLN (2.5mg/dL[0.81mmol/L]), as averaged across dose cycles between baseline and their last administered dose.
Description
To establish the effect of burosumab treatment on maintaining serum phosphorus levels to within normal range in adults with XLH.
Time Frame
Serum phosphorous levels will be monitored from Screening and every 12 weeks until the end of the study, at approximately 144 weeks.
Secondary Outcome Measure Information:
Title
Effect of burosumab on pre-existing pseudofracture healing will be monitored by centrally read targeted X-Ray
Description
Targeted radiography at locations pre-determined by the skeletal survey performed during UX023-CL303 or UX023-CL304 will be taken to monitor healing of pseudofractures and/or fractures.
Time Frame
Targetted X-Rays at ongoing fracture sites will be taken at the End of Study Visit, approximately week 144.
Title
Effect of burosumab on patients walking ability measured using the 6 Minute Walk Test.
Description
Patient's motor function by sustained walking will be evaluated using the 6 Minute Walk Test. (6MWT). The percent predicted values for the 6MWT will be calculated using published normative data based on age, gender and height.
Time Frame
The 6MWT will be measured at Baseline and then every 12 weeks for the first 48 weeks and then every 24 weeks for up to 144 weeks
Title
Effect of burosumab on Patient mobility assessed using the Timed Up and Go Test (TUG).
Description
The TUG assesses transitions during ambulatory activity incorporating strength, agility and dynamic balance assessments. The TUG score will be reported as the time (in seconds) that a subject takes to rise from a chair, walk three meters (approximately 10 feet), turn around, walk back to the chair and sit down.
Time Frame
The TUG Test will be assessed at Baseline and then every 12 weeks for the first 48 weeks and then every 24 weeks for up to 144 weeks
Title
Effect of burosumab on stiffness and physical function will be assessed using WOMAC.
Description
The patient's impression of their stiffness and physical function will be assessed by administering the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire- a 24 item patient reported questionnaire. The WOMAC will be administered in a 5-point Likert-scale format using descriptors of none, mild, moderate, severe and extreme corresponding to an ordinal scale of 0 to 4. Higher scores on the WOMAC indicate worse stiffness and functional limitations.
Time Frame
The WOMAC questionnaire will be administered at Baseline and then every 12 weeks for 48 weeks and every 12 weeks for up to 48 weeks and then every 24 weeks for up to 96 weeks
Title
Effect of burosumab on patient's pain severity and the impact of pain on functioning will be assessed using the Short-form Brief Pain Inventory questionnaire.
Description
The patient's recall of pain over a 24 hour period will be captured by administering the short form of the Brief Pain Inventory (BPI) questionnaire. The BPI evaluates the condition of all pain over the previous 24 hours. Two dimensions are measured: pain severity (worst, least, average and now) and the impact of pain on functioning (pain interference with general activity, walking, work, mood, enjoyment of life, relations with others and sleep).
Time Frame
The BPI will be administered at Baseline and then every 12 weeks for 48 weeks and then every 24 weeks for up to 144 weeks
Title
Effect of burosumab on patient's fatigue and the interference of fatigue on daily life over a 24 hour period.
Description
The patient's recall of fatigue will be captured by administering the Brief Fatigue Inventory (BFI) questionnaire. The BFI is a self-reported questionnaire consisting of nine items related to fatigue that are rated on a 0 to 10 numerical rating scale with a recall period of 24 hours. Two dimensions are measured: fatigue and the interference of fatigue on daily life. The change from baseline to post-baseline visits will be assessed.
Time Frame
The BFI will be administered at Baseline and then every 12 weeks for up to 48 weeks and then every 12 weeks for up to 144 weeks
Title
Effect of burosumab on bone metabolism and phosphate homeostasis using urinary phosphorus as PD marker.
Description
Pharmacodynamic assessment.
Time Frame
Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks
Title
Effect of burosumab on enthesopathy will be monitored by centrally read targeted X-Ray.
Description
Lateral foot views (bilateral) will be obtained in all subjects at Screening (as part of skeletal survey) and at End of Study (EOS). Size of enthesopathy spurs at both the superior and inferior calcaneus will be measured in two dimensions.
Time Frame
Lateral foot views (bilateral) will be obtained at screening and at End of Study, approximately week 88.
Title
Effect of burosumab on bone metabolism and phosphate homeostasis using Serum Phosphorus as PD marker.
Description
Pharmacodynamic assessment.
Time Frame
Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Title
Effect of burosumab on bone metabolism and phosphate homeostasis using serum 1, 25(OH)2D as PD marker.
Description
Pharmacodynamic assessment.
Time Frame
Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Title
Effect of Burosumab on phosphate reabsorption as measured by the ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtrate [TmP/GFR].
Description
Pharmacodynamic assessment.
Time Frame
Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Title
Effect of burosumab on health related quality of life as measured by SF-36v2
Description
Patients will answer questions around their physical functioning, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health
Time Frame
The SF-36v2 will be administered at Baseline and then every 12 weeks for 48 weeks and then every 24 weeks for up to 144 weeks

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
70 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Subjects who provide written informed consent after the nature of the study has been explained, and prior to any research-related procedures. Subjects who participated in Study UX023-CL303 or UX023-CL304. Any subjects that did not complete Study UX023-CL303 or UX023-CL304 may be included on a case-by-case basis. Subjects' enrolment is not dependent on any response to Primary or Secondary endpoints in studies UX023-CL303 or UX023-CL304. Willing to provide access to prior medical records for the collection of historical growth, biochemical and radiographic data, and disease history. 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. 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. Exclusion Criteria: 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. Presence of a concurrent disease or condition that would interfere with study participation or affect safety in the opinion of the investigator or Sponsor. 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. 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. Subjects who discontinued treatment from Study UX023-CL303 or UX023-CL304 due to either a grade ≥3 treatment-related hypersensitivity reaction or a burosumab-related hypersensitivity reaction reported as a SAE.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Peter Kamenicky
Organizational Affiliation
CHU de Bicêtre
Official's Role
Principal Investigator
Facility Information:
Facility Name
CHU de Bicetre
City
Le Kremlin-Bicêtre
ZIP/Postal Code
94275
Country
France
Facility Name
Hopital Lariboisiere
City
Paris
ZIP/Postal Code
75010
Country
France
Facility Name
Hopital Cochin
City
Paris
ZIP/Postal Code
75014
Country
France
Facility Name
St. Vincent's University Hospital
City
Dublin
ZIP/Postal Code
D04 T6F4
Country
Ireland
Facility Name
Azienda ospedaliera universitaria Careggi
City
Florence
ZIP/Postal Code
50139
Country
Italy
Facility Name
Western General Hospital
City
Edinburgh
ZIP/Postal Code
EH4 2XU
Country
United Kingdom
Facility Name
National Hospital for Neurology and Neurosurgery-University College London Hospitals NHS Foundation Trust
City
London
ZIP/Postal Code
WC1N 3BG
Country
United Kingdom
Facility Name
Nuffield Orthopaedic Centre - Oxford University Hospitals Nhs Trust
City
Oxford
ZIP/Postal Code
OX3 7LD
Country
United Kingdom
Facility Name
Northen General Hospital
City
Sheffield
ZIP/Postal Code
S5 7AU
Country
United Kingdom
Facility Name
Royal National Orthopaedic Hospital NHS Trust
City
Stanmore
ZIP/Postal Code
HA7 4LP
Country
United Kingdom

12. IPD Sharing Statement

Plan to Share IPD
No

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Study of the Anti-FGF23 Antibody, Burosumab, in Adults With XLH

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