Efficacy and safety of two doses of Norditropin® (somatropin) in short stature due to Noonan syndrome: a 2-year randomized, double-blind, multicenter trial in Japanese patients.

Abstract

This randomized double-blind multicenter trial (NCT01927861) evaluated the growth-promoting effect and safety of Norditropin® (NN220; somatropin) in Japanese children with short stature due to Noonan syndrome. Prepubertal children aged 3-<11 years (boys) or 3-<10 years (girls) with Noonan syndrome were randomized to receive GH 0.033 mg/kg/day (n = 25, mean age 6.57 years, 11 females) or 0.066 mg/kg/day (n = 26, mean age 6.06 years, eight females) for 104 weeks. Change in height standard deviation score (HSDS) from baseline was analyzed based on an ANCOVA model. Baseline HSDS was -3.24. Estimated change in HSDS [95% CI] after 104 weeks' treatment was 0.84 [0.66, 1.02] and 1.47 [1.29, 1.64] for the lower and higher doses, respectively; estimated mean difference 0.63 [0.38, 0.88], p < 0.0001. Rates and patterns of adverse events (AEs) were similar between groups. Most were mild and reported as unlikely to be related to Norditropin®. There were no withdrawals due to AEs. Insulin-like growth factor-I SDS increased from -1.71 to -0.64 (0.033 mg/kg/day) and to 0.63 (0.066 mg/kg/day). HbA1c increased slightly (0.033 mg/kg/day: +0.14%; 0.066 mg/kg/day: +0.13%); glucose profiles were almost unchanged; insulin profiles increased in both groups in the oral glucose tolerance test. There were no clinically significant abnormal electrocardiogram or echocardiography findings. We conclude that Norditropin® at doses of 0.033 mg/kg/day or 0.066 mg/kg/day for 104 weeks increases height in Japanese children with short stature due to Noonan syndrome, with a favorable safety profile. The effect was greater with 0.066 mg/kg/day compared with 0.033 mg/kg/day.