CompletedPhase 2

Study of Burosumab (KRN23) in Adults With Tumor-Induced Osteomalacia (TIO) or Epidermal Nevus Syndrome (ENS)

United States17 participantsStarted 2015-03-24

Plain-language summary

The primary objectives of this study are to evaluate the effect of burosumab treatment on: * Increasing serum phosphorus levels in adults with TIO or ENS-associated osteomalacia * Improvement in TIO/ENS-associated osteomalacia as determined by osteoid thickness (O.Th), osteoid surface/bone surface (OS/BS), osteoid volume/bone volume (OV/BV) and mineralization lag time (MLt).

Who can participate

Age range

18 Years

Sex

ALL

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

. Have a clinical diagnosis of TIO/ENS-associated osteomalacia based on evidence of excessive fibroblast growth factor 23 (FGF23) that was not amenable to cure by surgical excision of the underlying tumor/lesion (documented by Investigator).
. Be ≥ 18 years of age
. Have a fasting serum phosphorus level \< 2.5 mg/dL
. Have an FGF23 level ≥ 100 pg/mL by Kainos assay
. Have a ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtration rate (TmP/GFR) \< 2.5 mg/dL
. Have an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min (using Cockcroft-Gault formula). Subjects with eGFR ≥ 30 but \< 60 mL/min will be considered eligible as long as in the opinion of the investigator the decline in renal function is not related to nephrocalcinosis.

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

Percentage of Participants Achieving Mean Serum Phosphorus Levels Above 2.5 mg/dL at the Mid-Point of the Dose Intervals Between Baseline and Week 24

Timeframe: Mid-point of each dose interval from Baseline to Week 24 (Weeks 2, 6, 10, 14 and 22 [there was no study visit at Week 18])

Change From Baseline to Week 48 in Osteoid Thickness

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Osteoid Surface/Bone Surface (OS/BS)

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Osteoid Volume/Bone Volume (OV/BV)

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Mineralization Lag Time (MLt)

Timeframe: Baseline, Week 48

Trial details

NCT IDNCT02304367

SponsorKyowa Kirin, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2017-07-27

Results submitted2020-07-10

View on ClinicalTrials.gov More Tumor Induced Osteomalacia (TIO) trials

Plain-language summary

Who can participate

Age range

18 Years

Sex

ALL

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

. Have a clinical diagnosis of TIO/ENS-associated osteomalacia based on evidence of excessive fibroblast growth factor 23 (FGF23) that was not amenable to cure by surgical excision of the underlying tumor/lesion (documented by Investigator).
. Be ≥ 18 years of age
. Have a fasting serum phosphorus level \< 2.5 mg/dL
. Have an FGF23 level ≥ 100 pg/mL by Kainos assay
. Have a ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtration rate (TmP/GFR) \< 2.5 mg/dL
. Have an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min (using Cockcroft-Gault formula). Subjects with eGFR ≥ 30 but \< 60 mL/min will be considered eligible as long as in the opinion of the investigator the decline in renal function is not related to nephrocalcinosis.

What they're measuring

Percentage of Participants Achieving Mean Serum Phosphorus Levels Above 2.5 mg/dL at the Mid-Point of the Dose Intervals Between Baseline and Week 24

Timeframe: Mid-point of each dose interval from Baseline to Week 24 (Weeks 2, 6, 10, 14 and 22 [there was no study visit at Week 18])

Change From Baseline to Week 48 in Osteoid Thickness

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Osteoid Surface/Bone Surface (OS/BS)

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Osteoid Volume/Bone Volume (OV/BV)

Timeframe: Baseline, Week 48

Change From Baseline to Week 48 in Mineralization Lag Time (MLt)

Timeframe: Baseline, Week 48

Study of Burosumab (KRN23) in Adults With Tumor-Induced Osteomalacia (TIO) or Epidermal Nevus Syndrome (ENS)

Plain-language summary

Who can participate

Inclusion criteria

Questions worth asking your doctor

Questions for the trial coordinator

What they're measuring

Trial details

Study of Burosumab (KRN23) in Adults With Tumor-Induced Osteomalacia (TIO) or Epidermal Nevus Syndrome (ENS)

Plain-language summary

Who can participate

Inclusion criteria

Questions worth asking your doctor

Questions for the trial coordinator

What they're measuring

Trial details

Exclusion criteria