Abstract
Background: Growth hormone (GH) is indicated for the treatment of short stature in children born small for gestational age (SGA) who fail to show catch-up growth. In pilot studies, early initiation of GH has been associated with favorable growth responses in short SGA children. However, few studies have examined the short- and long-term effects of initiating GH in children born SGA who are <4 years (yr) of age, compared with those starting later. This analysis therefore investigated the effect of age at GH initiation on long-term effectiveness and safety in children born SGA.
Methods: The NordiNet IOS (NCT00960128) and ANSWER (NCT01009905) programs are complementary, non-interventional, multicenter studies that evaluated the long-term effectiveness and safety of Norditropin (somatropin; Novo Nordisk A/S, Denmark) as prescribed in real-life clinical practice. In this analysis, children born SGA who were prepubertal at GH initiation were grouped according to age at GH start: <4 yr, 4-6 yr, and ≥6 yr. Patient characteristics at birth and at GH start, auxological measurements, and adverse events were evaluated in each group.
Results: Overall, 3351 SGA patients were included in the effectiveness set (age at GH start: <4 yr [n=389, 54.8% male]; 4-6 yr [n=1048, 57.6% male]; and ≥6 yr [n=1914, 56.6% male]). The proportion of patients born pre-term (<37-week gestation) was 38.6% in the <4 yr group, 36.1% in the 4-6 yr group, and 28.2% in the ≥6 yr group. Mean (SD) birth length standard deviation score (SDS) and birth weight SDS were: −2.9 (1.6) and −2.3 (1.2) in the <4 yr group, −2.8 (1.3) and −2.2 (1.1) in the 4-6 yr group, and −2.5 (1.4) and −2.0 (1.2) in the ≥6 yr group. Mean (SD) age at GH start was 3.1 (0.7), 4.9 (0.6), and 9.3 (2.2) years in the <4 yr, 4-6 yr, and ≥6 yr groups, respectively. Mean (SD) GH duration and daily GH dose in the study were: 3.5 (3.1) yr and 0.044 (0.016) mg/kg in the <4 yr group, 4.1 (3.1) yr and 0.039 (0.012) mg/kg in the 4-6 yr group, and 3.5 (2.5) yr and 0.042 (0.012) mg/kg in the ≥6 yr group. Mean (SD) height SDS (HSDS) at GH start was −3.3 (1.2) in the <4 yr group, −3.1 (0.9) in the 4-6 yr group, and −2.8 (0.8) in the ≥6 yr group. After 4 and 8 yr of GH, mean (SD) ΔHSDS from baseline was 1.7 (0.7) and 2.5 (0.6) in the <4 yr group, 1.6 (0.7) and 2.2 (0.8) in the 4-6 yr group and 1.3 (0.7), and 1.7 (0.6) in the ≥6 yr group. Among patients who reached near-adult height in the study, mean (SD) HSDS was −1.9 (0.6) in the <4 yr group (n=3), −1.9 (0.8) in the 4-6 yr group (n=10), and −1.8 (1.0) in the ≥6 yr group (n=220). In the safety set (n=5643), the most commonly reported non-serious adverse reactions (AR) were headache (n=20) and arthralgia (n=5). The most common serious ARs were headache (n=3) and epiphysiolysis (n=4). ARs and serious ARs were distributed equally among groups.
Conclusions: This analysis of real-world data confirms the effectiveness and safety of GH in children born SGA, irrespective of patient age at treatment initiation.
Effectiveness and Safety of Early Growth Hormone Treatment in Children Born Small for Gestational Age: Long-Term Data From NordiNet® International Outcome Study (IOS) and ANSWER Program
