A Research Study of How Well Macimorelin Works to Find Out if Children Have a Lack of Growth Hormone and How Safe it is

What Was Tested

The trial (phase 3) is built around Macimorelin (non-peptide).

The stimulation test will use a new growth hormone stimulating substance called macimorelin.

By now, only adults in the USA can get this new stimulation test.

It had two arms (groups): standard GHST order randomized: arginine - clonidine (active comparator) and standard GHST order randomized: clonidine - arginine (active comparator).

At visit 2 (V2), all subjects will perform the macimorelin GHST and will be randomized 1:1 to the order of the clonidine and arginine GHSTs at visit 3 (V3) and visit 4 (V4). In this arm, those subjects will be presented which will have been randomized to the arginine GHST at V3 and the clonidine GHST at V4. At visit 5 (V5) all subjects will perform the macimorelin GHST.

At V2, all subjects will perform the macimorelin GHST and will be randomized 1:1 to the order of the clonidine and arginine GHSTs at V3 and V4. In this arm, those subjects will be presented which will have been randomized to the clonidine GHST at V3 and to the arginine GHST at V4. At V5 all subjects will perform the macimorelin GHST.

The registry classes the interventions as diagnostic test and drug.

More on the Plan

Each study participant (patient) will have 5 to 6 visits in total with the study doctor.

The study will last for about 1 to 4 months, dependent on how close the visits are done.

At the visits 2, 3, 4 and 5, the patient will get a stimulation test done and blood samples will be taken.

At those 4 visits, the patient will have either to drink a macimorelin drink, take some clonidine tablets or get an arginine infusion.

Who Took Part

The registry lists 101 actual participants took part.

It was open to people of any sex aged from 2 years up to 17 years.

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

Examples of who could join: Male and female pediatric subjects from 2 to less than 18 years of age at the time of signing informed consent. Indication for the performance of growth hormone stimulation test. Presence of a height measurement minimum 6 and maximum 18 months prior to screening.

The full record lists 4 inclusion and 17 exclusion criteria; among the exclusions: ongoing growth hormone therapy; presence of hypothyroidism and/or adrenal insufficiency without adequate and stable replacement therapy treatment for at least 30 days prior to first ghst; medical history of ongoing clinically symptomatic psychiatric disorders.

How the Study Was Run

The set-up was randomized, crossover and single-blind.

Because people in this Macimorelin (non-peptide) study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both Macimorelin (non-peptide) and the comparison in turn, acting as their own control.

Only one side, usually the participants, was kept unaware of whether Macimorelin (non-peptide) was given.

Those kept unaware of assignments: outcomes assessor.

It started in 2021-11-16 with completion listed for 2024-06-13.

It ran at 45 sites in United States (12), Romania (8), Italy (5), Poland (4), Turkey (Türkiye) (4) and Georgia (3).

Its stated primary purpose is diagnostic.

What Was Measured

Researchers chose this as the main measure: Area under the Receiver Operator Characteristic curve (ROC AUC) based on GH concentration during GHST following macimorelin administration.

It also tracked 3 secondary outcomes, for example Sensitivity for the macimorelin GHST, Specificity for the macimorelin GHST and Overall agreement between the outcome of the macimorelin GHST and the combined outcome from the 2 standard GHSTs.

What This Means in Plain Language

Put simply, this is a phase 3, randomized trial of Macimorelin (non-peptide) in 101 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Macimorelin (non-peptide) compound page, all human trials.