Extension Study of Infigratinib in Children With Achondroplasia (ACH)

Key Rollover Subjects Inclusion Criteria:

• Pediatric subjects with ACH who have completed a previous QED-sponsored interventional study with infigratinib.
• Subjects and parent(s), legal guardian(s), or caregiver(s) are willing and able to comply with study visits and study procedures.
• Subjects are able to swallow oral medication.
• Negative pregnancy test in girls ≥10 years of age or girls of any age who have experienced menarche.
• If sexually active, subject must be willing to use a highly effective method of contraception while taking study drug and for 1 month after the last dose of study drug.
• The PI, or a person designated by the PI, will obtain written informed consent from each subject's parent(s), legal guardian(s), or caregiver(s) and the subject's assent, when applicable, before any study-specific activity is performed.

Key Rollover Subjects Exclusion Criteria:

• Subject has concurrent circumstance, disease, or condition that, in the view of the PI and/or sponsor, would interfere with study participation or safety evaluations.
• Subjects who developed a medical condition that will require the initiation of treatment with a prohibited medication.
• Subjects prematurely discontinued a prior QED-sponsored interventional study with infigratinib
• Current participation in an ongoing clinical study with a sponsor other than QED
• Subjects that have reached final height or near final height.

Key Inclusion Criteria for Treatment Naïve Subjects

• Subject must be 3 to <18 years of age at screening and have growth potential.
• Subjects and parent(s), legal guardian(s), or caregiver(s) are willing and able to comply with study visits and study procedures.
• Subjects are able to swallow oral medication.
• Subjects who have a diagnosis of ACH, documented clinically and confirmed by genetic testing.
• Subjects have at least a 6-month period of growth assessment in the PROPEL study (Protocol QBGJ398 001) before study entry.
• Negative pregnancy test in girls ≥10 years of age or girls of any age who have experienced menarche.
• If sexually active, subject must be willing to use a highly effective method of contraception while taking study drug and for 1 month after the last dose of study drug.
• The PI, or a person designated by the PI, will obtain written informed consent from each subject's parent(s), legal guardian(s), or caregiver(s) and the subject's assent, when applicable, before any study-specific activity is performed.

Key Exclusion Criteria for Treatment Naïve Subjects

• Subjects who have hypochondroplasia or short stature condition other than ACH (e.g., trisomy 21, pseudoachondroplasia, psychosocial short stature).
• Subjects who have significant concurrent disease or condition that, in the view of the PI and/or sponsor, would represent an increased risk to the subject or would interfere with study participation or safety evaluations.
• Subjects who have a history of malignancy.
• Subjects who are currently receiving treatment with agents that are known strong inducers or inhibitors of cytochrome P450 (CYP) 3A4.
• Subjects who discontinued treatment with prohibited medications for at least 5 half-lives before screening are eligible.
• Subjects who have received treatment with growth hormone, insulin-like growth factor 1 (IGF 1), anabolic steroids or any investigational or approved drug for the treatment of ACH in the previous 6 months.
• Subjects who have significant abnormality in screening laboratory results.
• Subjects who have had a fracture within 12 months of screening.