SAT-282 Outcomes in Children Treated with Growth Hormone for Prader-Willi Syndrome: Data from the Answer® Program and Nordinet® International Outcome Study (IOS)

Abstract

Background: The American Norditropin® Studies: Web-Enabled Research (ANSWER) Program and the NordiNet® International Outcome Study (NordiNet® IOS) are complementary, large-scale, non-interventional studies designed to gather long-term data on the effectiveness and safety of Norditropin® (somatropin) treatment in the usual clinical setting. Data were collected in the United States (US) and Europe from 2006 to 2016 in both children and adults. Objective: To assess the clinical outcomes of growth hormone (GH)-treated pediatric patients with Prader-Willi Syndrome (PWS) enrolled in the ANSWER® Program or NordiNet® IOS. Methods: Patient information was entered by participating physicians using a web-based data entry tool. Change from baseline in height standard deviation scores (HSDS) and body mass index standard deviation scores (BMI SDS) were analyzed based on availability of follow-up data. The explanatory variables in the repeated measures model analysis included baseline HSDS/BMI SDS, gender, age, target height, region (US/Europe), and GH dose. Results: From a total of 129 PWS GH-naïve patients, available data for HSDS and BMI SDS analysis included 129 and 98 patients respectively on a GH dose of 0.03 (±0.01) mg/kg/d. In the HSDS analysis with equal number of males and females, the mean age at the start of treatment was 4.42 (±4.51) years, and mean treatment period was 2.48 (±1.31) years. Further analysis determined that baseline age and years on treatment had a significant impact on the change in HSDS (P=0.014 and P<0.0001, respectively. In the BMI SDS analysis, 51% were males. At the start of treatment, the mean age was 5.56 (±4.79) years, with a mean duration of GH treatment of 2.45 (±1.32) years. The mean BMI was 18.04 (±4.9) for NordiNet® patients and 24.68 (±7.75) for ANSWER® patients. The baseline BMI SDS of NordiNet® patients (0.4±1.54) was lower compared with that of ANSWER® patients (1.80±1.68). Longer GH treatment time lead to a greater change in BMI SDS from baseline (P<0.0001). In addition, those patients with a higher BMI at the start of treatment had a greater decrease in BMI over time [t(624)=-8.01, P<0.0001]. Conclusions: GH is effective in the management of children with PWS. Earlier treatment resulted in a greater gain in height, and longer treatment period resulted in better outcomes for both height and BMI.