Context: Small clinical trials of GH treatment of idiopathic short stature (ISS) show variable efficacy.
Objective: The study was an analysis of a large GH registry for efficacy and safety of GH treatment of ISS. There was also a comparison with a specific clinical trial.
Design: Up to 7 yr of GH treatment of ISS was evaluated for efficacy and safety in the National Cooperative Growth Study (NCGS).
Setting: The NCGS study was conducted at Genentech, Inc. and included 47,226 patients.
Patients: The ISS group included maximum stimulated GH 10 ng/ml or more and/or a report of ISS by investigator (n = 8018; all included for safety). Cohort 1 (n = 2520) was similar to the clinical trial, cohort 2 (n = 283) included subjects younger than 5 yr of age, and cohort 3 (n = 940) was pubertal at GH start.
Intervention: GH, approximately 0.30 mg/kg.wk, was given.
Main outcome measures: These included growth velocities and height sd (HtSDS).
Results: Mean first-year growth velocities in cohorts 1, 2, and 3 increased 4.6, 3.9, and 4.4 cm/yr over pretreatment, respectively. Measures included: baseline mean HtSDS, -2.9, -3.2, and -2.8; mean HtSDS at 1 yr, -2.4, -2.3, and -2.3, respectively. Mean HtSDS after 7 yr in cohorts 1 (n = 303) and 2 (n = 85) and 5 yr in cohort 3 (n = 58) were: -1.2, -1.0, and -1.5, respectively. Cohort 3 shorter treatment time was due to advanced baseline age (mean 13.8 yr) and puberty. Mean HtSDS gain in cohort 1 was comparable with the clinical trial. No new safety signals specific to the NCGS ISS population were observed.
Conclusion: ISS patients in the GH registry demonstrate a significant increase in HtSDS with the safety profile similar to GH-deficient patients. RESULTS were similar to the clinical trial.