A Trial to Assess the Safety and Efficacy of KRN23 in Epidermal Nevus Syndrome (ENS) (NCT04320316) | Clinical Trial Compass
CompletedPhase 4
A Trial to Assess the Safety and Efficacy of KRN23 in Epidermal Nevus Syndrome (ENS)
United States1 participantsStarted 2020-07-31
Plain-language summary
KRN23 is a fully human immunoglobulin monoclonal antibody (mAb) that binds to and inhibits the activity of fibroblast growth factor 23 (FGF23), leading to an increase in serum phosphorus levels. There are multiple disorders that result in unusually high circulating levels of FGF23, which in turn result in renal phosphate wasting and reduced levels of 1,25-dihydroxy vitamin D (1,25\[OH\]2D). Across these disorders the clinical symptoms are similar and often include osteomalacia (and, in children, rickets), muscle weakness, fatigue, bone pain, and fractures. KRN23 has been studied in one of these disorders, X-linked hypophosphatemia (XLH). In single- and repeat-dose clinical studies in subjects with XLH, subcutaneous (SC) administration of KRN23 consistently increased and sustained serum phosphorus levels and tubular reabsorption of phosphate (TRP) without a major impact on urine calcium levels or vitamin D metabolism. Positive results were also observed in a nonclinical pharmacology model of XLH. It is hypothesized that KRN23 may provide clinical benefit in this patient due to the common underlying feature in this patient and in patients with XLH - abnormally elevated FGF23 in the context of low age -adjusted serum phosphorous levels. The primary objective is to study the effect of KRN23 treatment on normalizing age-adjusted fasting serum phosphorous levels in a single pediatric patient with Epidermal Nevus Syndrome associated hypophosphatemic rickets.
Who can participate
Age range
6 Months
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Patient has confirmed ENS by physician diagnosis
* Patient has confirmed FGF23 elevations in the context of low serum phosphorous \< 4.1 mg/dL
* Patient able to tolerate KRN23 treatment
* Have a corrected serum calcium level \< 10.8mg/dL
* Have an eGFR \>60 ml/min
* Must be willing in the opinion of the investigator, to comply with study procedures and schedule
* Provide written informed consent by a parent after
Exclusion Criteria:
* Patient should not use CRYSVITA with Oral phosphate or active Vitamin D analogs.
* Patient and investigator should not initiate CRYSVITA if Phosphorus level is within or above normal.
* CRYSVITA is contraindicated in patients with severe renal impairment or end stage renal disease because these conditions are associated with abnormal mineral metabolism.
* The use or enrollment in studies using other investigational therapies including other monoclonal antibodies
* Subject and their Parent not willing or not able to give written informed consent
* In the Investigators opinion, the subject may not be able to meet all the requirements for study participation
* Subject has a history of hypersensitivity to KRN23 excipients that in the opinion of the investigator, places the subject at an increased risk of adverse effects
* Subject has a condition that in the opinion of the investigator could present a concern for subject safety or data interpretation.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
The Participant Will Achieve Normal Age-adjusted Phosphorous Levels as Tested by Fasting Serum Lab Values
Timeframe: every 2 week, from baseline to 52 weeks.