A Study (Phase 1b/2) of GS3-007a Oral Treatment in Children With Growth Hormone Deficiency (PGHD)

A Study to Evaluate the Safety and Tolerability of Multiple Ascending Doses of GS3-007a Dry Suspension in Patients With PGHD and to Evaluate the Efficacy and Safety of 52-week of Treatment With GS3-007a Dry Suspension: a Two-part, Multicenter, Randomized, Phase Ib/II Clinical Trial

This is a two-part clinical study for children with growth hormone deficiency. In the first part, participants will be randomly assigned to receive different doses of an oral treatment (GS3-007a dry suspension) or a placebo for 14 days. This part is double-blinded, meaning neither the participants nor the doctors will know who is receiving the treatment or placebo. The goal is to find a safe and well-tolerated dose.

In the second part, participants will be randomly assigned to receive either the selected dose of GS3-007a or another approved treatment for 52 weeks. This part is open-label, so everyone will know which treatment is being given. After that, all participants may continue taking GS3-007a for another 156 weeks in an extension phase to study long-term effects.

Inclusion Criteria:

• chronological age (CA) ≥3 years at Screening
• Prepubertal girls or boys
• Height at Screening lower than the reference height for normal children of the same chronological age and sex minus 2 standard deviations (-2 SD)
• A confirmed diagnosis of growth hormone deficiency (GHD)
• Having not been treated with any growth-promoting drugs
• BA delayed by ≥6 months compared with the CA at Screening Subjects who meet all of the following criteria are eligible to enroll in the extension study (applicable for Part II extension period)
• Subjects who have completed the 52-week treatment period of phase II
• Subjects who do not permanently discontinue the investigational Medicinal Product (IMP) during the 52-week treatment period of phase II

Exclusion Criteria:

• A highly allergic constitution
• Suspected or confirmed total pituitary deficiency, including patients previously confirmed with deficiency of ≥2 pituitary hormones other than GH
• Being confirmed with other chromosomal abnormalities or growth abnormalities affecting growth
• Congenital skeletal dysplasia or serious spinal anomalies
• Cognitive hypofunction, neurodevelopmental disorders, or psychiatric/psychological disorders that, in the investigator's opinion, may interfere with evaluation of study endpoints
• Any clinically significant abnormality that may affect growth or evaluation of the IMP
• Screening magnetic resonance imaging (MRI) scan of the sellar region confirming prior or current intracranial tumor growth
• Concurrent use of any medications that may affect growth or response to growth hormone therapy
• Epiphyseal closure
• Electrocardiogram (ECG) QTcF interval abnormal, with a history of QT/QTc interval prolonged
• Hepatic function indicators abnormal at Screening Patients meeting any of the following criteria may not be enrolled in this extension study (applicable for Part II extension period)
• Subjects with closed epiphyses
• Any clinically significant abnormality that may affect growth or evaluation of the IMP
• Known or suspected allergy to the IMP
• Women with positive blood human chorionic gonadotropin (hCG) at the pre-treatment visit