Efficacy and Safety Results of Long-Term Growth Hormone Treatment of Idiopathic Short Stature

Abstract

Small clinical trials of GH treatment of idiopathic short stature (ISS) show variable efficacy. 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. Up to 7 yr of GH treatment of ISS was evaluated for efficacy and safety in the National Cooperative Growth Study (NCGS). The NCGS study was conducted at Genentech, Inc. and included 47,226 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. GH, approximately 0.30 mg/kg.wk, was given. These included growth velocities and height sd (HtSDS). 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. 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.