Long-Term Effectiveness and Safety of Childhood Growth Hormone Treatment in Noonan Syndrome

Introduction: Few data exist on long-term growth hormone (GH) treatment in patients with Noonan syndrome (NS). Objective: To evaluate the effectiveness and safety of GH treatment in NS in clinical practice. Methods: Height gain, near-adult height (NAH), and safety were assessed in 2 complementary non-interventional studies: NordiNet (R) IOS and ANSWER. The safety analysis included 412 patients, and the effectiveness analysis included 84 GH-treated patients (male, n = 67) with >= 4 years' height standard deviation score (HSDS) data. HSDS was determined using national reference (NR) and NS-specific (NSS) data. Results: The mean (SD) baseline age was 8.38 (3.57) years; HSDS, -2.76 (1.03); GH dose, 41.6 (11.1) mu g/kg/day. The mean (SD) HSDS increase from baseline (Delta HSDS) was 0.49 (0.37) (first year), 0.79 (0.58) (second year), and 1.01 (0.60) (third year) (NR). The mean (SD) HSDS at year 3 was -1.66 (1.00) (NR; 1.06 [1.12] [NSS]). Twenty-four patients achieved NAH. The mean (SD) NAH SDS (NR) was -1.51 (0.60) (154.90 [3.21] cm) in females and -1.79 (1.09) (165.61 [7.19] cm) in males; 70.8% (17/24) had NAH SDS >= -2. Adverse drug reactions and GH-unrelated serious adverse events (n = 34) were reported in 22/412 (5.3%) patients. Four neoplasms and 3 cases of scoliosis were reported; no cardiovascular adverse events occurred. Conclusions: GH-treated children with NS achieved substantial height gain during the first 3 years of follow-up. Overall, 24 patients achieved NAH, with 70.8% having NAH SDS >= -2. There was no evidence to support a higher prevalence of neoplasm, or cardiac or other comorbidities.

Automated summary

This study evaluated the effectiveness and safety of GH treatment in patients with NS, finding significant height gain in patients over 3 years, with 24 patients achieving near-adult height, the majority with a height standard deviation score above -2. The occurrence of adverse drug reactions and serious events was relatively low.