Open Label Trial Assessing Safety and Efficacy of Burosumab (KRN23), in a Patient With ENS and Hypophosphatemic Rickets

Pain, Chronic Clinical Trial

Official title:

An Open Label Trial to Assess the Safety and Efficacy of Burosumab (KRN23), an Investigational Antibody to FGF23, in a Single Pediatric Patient With Epidermal Nevus Syndrome(ENS) and Associated Hypophosphatemic Rickets

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03581591
• Other study ID #: ENSKRN23.1
• Status: Completed
• Phase: Phase 3
• Start date: January 31, 2018
• Est. completion date: December 6, 2019

Study information

• Verified date: January 2020
• Source: Redwood Dermatology Sciences
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A 52 week, open label trial to assess the safety and efficacy of KRN23, an investigational antibody to FGF23, in a single pediatric patient with Epidermal Nevus Syndrome(ENS) and associated hypophosphatemic rickets

A 26 weeks extension to original study to monitor patient lab results for her safety.

Description:

1.1 Primary Objective

The effect of KRN23 treatment on normalizing age-adjusted serum phosphorous levels in a single pediatric patient with Epidermal Nevus Syndrome associated hypophosphatemic rickets

1.2 Secondary Objectives

1. The PD profile of KRN23 as assessed by changes from baseline over time 1,25(OH)2D, iPTH, Serum Calcium, TRP and TmP/GFR (the ratio of renal tubular maximum phosphate reabsorption rate to glomerular filtration rate)

2. Changes in underlying skeletal disease/rickets as assessed by standard radiographs utilizing the Radiographic Global Impression of Change (RGI-C) rating scales

3. Effects of KRN23 on biochemical markers of bone turnover that reflect rickets severity, alkaline phosphatase (ALP)

4. Walking ability as assessed by 6-Minute Walk Test (6MWT)

5. Patient/parent-Reported Outcomes as assessed by PROMIS and FPS-R rating scales

1.3 Exploratory Objective

1. Dual-energy X-ray absorptiometry (DXA)

1.4 Safety Objective Assess the safety of KRN23 administration in a single patient with ENS-associated hypophosphatemic rickets, based on adverse events (AEs), laboratory assessments, cardiac imaging and renal ultrasound.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 1
• Est. completion date: December 6, 2019
• Est. primary completion date: December 6, 2019
• Accepts healthy volunteers: No
• Gender: Female
• Age group: N/A to 18 Years

Eligibility

Inclusion Criteria:

1. Patient has confirmed ENS by physician diagnosis

2. Patient has confirmed FGF23 elevations in the context of low serum phosphorous < 4.1 mg/dL

3. Patient able to tolerate KRN23 treatment

4. Have a corrected serum calcium level < 10.8mg/dL

5. Have an eGFR >60 ml/min

6. Must be willing in the opinion of the investigator, to comply with study procedures and schedule

7. Provide written informed consent by a parent after the study has been explained and prior to any research related procedures begin

Exclusion Criteria:

1. Concomitant use of active vitamin D (i.e calcitriol) and/or exogenous phosphate supplementation. Patient will be allowed OTC Vitamin D should levels drop below <20 ng/ml

2. The use or enrollment in studies using other investigational therapies including other monoclonal antibodies

3. Subject and their parent not willing or not able to give written informed consent

4. In the Investigators opinion, the patient may not be able to meet all the requirements for study participation

5. Patient has a history of hypersensitivity to KRN23 excipients that in the opinion of the investigator, places the patient at an increased risk of adverse effects

6. Patient has a condition that in the opinion of the investigator could present a concern for subject safety or data interpretation.

Related Conditions & MeSH terms

• Chronic Pain
• Familial Hypophosphatemic Rickets
• Hypophosphatemia
• Hypophosphatemic Rickets
• Pain, Chronic
• Rickets

Intervention

Biological:
• Burosumab
recombinant human IgG1 monoclonal antibody to fibroblast growth factor 23)

Locations

Country	Name	City	State
United States	The Focus Center, PC	Clinton	Utah

Sponsors (2)

Lead Sponsor	Collaborator
Redwood Dermatology Sciences	Ultragenyx Pharmaceutical Inc

Country where clinical trial is conducted

United States, 

References & Publications (4)

Aono Y, Hasegawa H, Yamazaki Y, Shimada T, Fujita T, Yamashita T, Fukumoto S. Anti-FGF-23 neutralizing antibodies ameliorate muscle weakness and decreased spontaneous movement of Hyp mice. J Bone Miner Res. 2011 Apr;26(4):803-10. doi: 10.1002/jbmr.275. — View Citation

Aono Y, Yamazaki Y, Yasutake J, Kawata T, Hasegawa H, Urakawa I, Fujita T, Wada M, Yamashita T, Fukumoto S, Shimada T. Therapeutic effects of anti-FGF23 antibodies in hypophosphatemic rickets/osteomalacia. J Bone Miner Res. 2009 Nov;24(11):1879-88. doi: 10.1359/jbmr.090509. — View Citation

Carpenter TO, Imel EA, Ruppe MD, Weber TJ, Klausner MA, Wooddell MM, Kawakami T, Ito T, Zhang X, Humphrey J, Insogna KL, Peacock M. Randomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia. J Clin Invest. 2014 Apr;124(4):1587-97. doi: 10.1172/JCI72829. Epub 2014 Feb 24. — View Citation

Lim YH, Ovejero D, Sugarman JS, Deklotz CM, Maruri A, Eichenfield LF, Kelley PK, Jüppner H, Gottschalk M, Tifft CJ, Gafni RI, Boyce AM, Cowen EW, Bhattacharyya N, Guthrie LC, Gahl WA, Golas G, Loring EC, Overton JD, Mane SM, Lifton RP, Levy ML, Collins MT, Choate KA. Multilineage somatic activating mutations in HRAS and NRAS cause mosaic cutaneous and skeletal lesions, elevated FGF23 and hypophosphatemia. Hum Mol Genet. 2014 Jan 15;23(2):397-407. doi: 10.1093/hmg/ddt429. Epub 2013 Sep 4. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The effect of KRN23 treatment on normalizing age-adjusted serum phosphorous levels in a single pediatric patient with Epidermal Nevus Syndrome associated hypophosphatemic rickets		18 months