Calcitonin for Treating X-linked Hypophosphatemia

What Was Tested

The trial (not phased) is built around Calcitonin.

X-linked hypophosphatemia (XLH) is the most common form of inherited rickets in the United States.

It also causes bone disease in adults.

XLH is caused by overproduction of a hormone call FGF23, which makes the body waste phosphate.

It had two arms (groups): Nasal calictonin (experimental) and Saline Nasal spray (placebo comparator).

Subjects will received nasal calcitonin once daily.

Patients will receive saline nasal spray once daily.

The registry classes the interventions as drug.

More on the Plan

The pathophysiology of X-linked hypophosphatemia (XLH) was clarified with the report in 1995 by the HYP Consortium led by Dr.

Michael Econs, that mutations in the neutral endopeptidase PHEX, are the genetic basis for this disorder (Nature Genetics 11:130).

By a pathway that remains unclear, loss-of-function mutations in PHEX lead to elevated circulating levels of FGF23.

It is now well established that FGF23 is the proximate biological mediator of this syndrome.

Who Took Part

Enrollment: 21 actual participants took part.

It was open to people of any sex aged from 18 years up to 80 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Age ≥18 or greater. An established diagnosis of XLH. Fasting PTH at time of screen \</= 1.7 times the upper limit of normal.

The full record lists 4 inclusion and 4 exclusion criteria; among the exclusions: inability to comply with instructions and appropriate follow up visits; treatment with agents that may skeletal metabolism such as glucocorticoids, bisphosphonates, denosumab, teriparatide, estrogen and anticonvulsants.

How the Study Was Run

Design: randomized, parallel-group and double-blind.

Because people in this Calcitonin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Groups ran in parallel: each of the participants stayed in one arm throughout.

As a double-blind Calcitonin study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant and investigator.

It started in 2011-03 with completion listed for 2015-09.

It ran at 1 site in United States.

Its stated primary purpose is treatment.

What Was Measured

Primary outcome: Area Under the Curve for FGF23 (time frame: Time 0). Area Under the Curve for FGF23 (time frame: 3 months).

It also tracked 16 secondary outcomes, for example Area Under the Curve for TmP/GFR, Area Under the Curve for 1,25(OH)2vitamin D, Number of Patients With Nasal Congestion at Baseline, Area Under the Curve for TmP/GFR, Area Under the Curve for 1,25(OH)2vitamin D and Number of Participants With Nasal Congestion at 1 Month.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Calcitonin in 21 people.

Its size is small, so on its own it can only give an early look.

The trial is marked completed; results are posted on the registry, and this page does not restate them.

More context: the Calcitonin compound page, all human trials.