Table of Contents
- Clinical trial overview
- Trials in achondroplasia
- Trials in hypochondroplasia
- Study designs and phases
- Main endpoints and what they mean
- Who the studies are for
Clinical trial overview
The available studies are investigating Infigratinib in children with growth conditions, mainly achondroplasia and hypochondroplasia.[1][2][3][4][5] The research is focused on whether the treatment is safe, how well it is tolerated, and whether it can improve growth over time.[1][3][4][5]
The studies include a completed Phase 3 trial, several authorised studies, and long-term extension research.[1][2][3][4][5] Some studies use a double-blind design, which means neither the family nor the study team knows who receives Infigratinib or placebo during the blinded part of the trial.[1]
Trials in achondroplasia
One Phase 3 study in children with achondroplasia was a double-blind, placebo-controlled trial with 110 participants.[1] It studied children 3 to under 18 years of age who had potential to grow, and its main endpoint was the change in height velocity at Week 52 compared with placebo.[1]
Another achondroplasia study is a Phase 2 long-term trial with 300 participants.[3] Its goals are to evaluate safety, tolerability, and changes over time in standing height Z-score, which is a way to compare a child’s height with standard growth charts.[3]
A further authorised Phase 2 study focuses on infants and young children with achondroplasia, with 77 planned participants.[4] This study includes several parts, such as a single ascending dose part, a Phase 2 part, a Phase 2b part, and an extension part, and it measures safety, pharmacokinetics, and growth outcomes.[4] Pharmacokinetics means how the body handles the study drug over time, including exposure levels and active metabolites, which are breakdown products that may still have activity.[4]
The main growth outcome in this infant and young child study is change in body length Z-score from baseline to Week 52, along with detailed safety checks such as vital signs, lab tests, imaging, eye exams, dental findings, and developmental milestones.[4]
Trials in hypochondroplasia
In hypochondroplasia, one authorised study is a Phase 4 open-label followed by double-blind, placebo-controlled trial with 139 participants.[2] It looks at children 5 to 11 years old in one part of the study and children 3 to under 18 years old in another part.[2] The study measures height velocity at Week 26 and change in height velocity or AHV, which means annualized height velocity, at Week 52 compared with placebo.[2]
Another hypochondroplasia study is a Phase 2 open-label long-term extension trial with 98 participants.[5] It is designed to evaluate long-term safety, tolerability, and changes in standing height Z-score over time.[5] The study also follows safety findings such as laboratory tests, eye and dental evaluations, and imaging studies like x-rays and DXA scans, which measure bone density and body composition.[5]
Study designs and phases
The trials use different study designs to answer different research questions.[1][2][4][5] A placebo-controlled study compares Infigratinib with an inactive treatment so researchers can see whether any changes are due to the study drug.[1][2]
The Phase 2 studies are mainly looking for early evidence of benefit and more detail on safety in smaller groups of children.[3][4][5] The Phase 3 and Phase 4 studies are larger or later-stage studies that help confirm benefit and continue long-term safety follow-up.[1][2]
Some studies also include an extension part, which means children who finish the main study can keep taking part for longer follow-up.[4][5]
Main endpoints and what they mean
The main endpoint in the Phase 3 achondroplasia trial is change from baseline in AHV, compared with placebo, at Week 52.[1] Baseline means the starting point before treatment begins, and AHV means annualized height velocity, or how fast a child grows in a year.[1]
In the hypochondroplasia Phase 4 study, the key endpoints include height velocity at Week 26 and change in AHV at Week 52 compared with placebo.[2] In the long-term hypochondroplasia extension study, the main focus is safety and changes in standing height Z-score over time.[5]
In the infant and young child achondroplasia study, researchers also track safety events that lead to dose reduction or stopping treatment, as well as growth, lab results, eye findings, dental development, and developmental milestones.[4] These measures help show both whether the treatment is tolerated and whether it may support normal growth and development.[4]
Who the studies are for
These trials are designed for children, not adults, and the age ranges differ by study.[1][2][3][4][5] Some studies include children 3 to under 18 years old, while others focus on ages 5 to 11 years or on infants and young children under 3 years old.[1][2][4]
The trials are aimed at children with short stature related to achondroplasia or hypochondroplasia who still have growth potential.[1][2][3][4][5] In the study data, “potential to grow” means the child is still expected to have room for further growth during the study period.[1][2]




