Growth hormone therapy in children born small for gestational age: results from the ANSWER program

The Exon 3-Deleted Growth Hormone Receptor (d3GHR) Polymorphism-A Favorable Backdoor Mechanism for the GHR Function

Growth hormone (GH) is a peptide hormone that plays a crucial role in controlling growth, development, and lifespan. Molecular regulation of GH is accomplished via the GH receptor (GHR), which is the main factor influencing human development and is essential to optimal functioning of the GH/IGF-I axis. Two GHR isoforms have been studied, according to the presence (flGHR) or absence (d3GHR) of exon 3. The d3GHR isoform, which lacks exon 3 has recently been related to longevity; individuals carrying this isoform have higher receptor activity, improved signal transduction, and alterations in the treatment response and efficacy compared with those carrying the wild type (WT) isoform (flGHR). Further, studies performed in patients with acromegaly, Prader-Willi syndrome, Turner syndrome, small for gestational age (SGA), and growth hormone deficiency (GHD) suggested that the d3GHR isoform may have an impact on the relationship between GH and IGF-I levels, height, weight, BMI, and other variables. Other research, however, revealed inconsistent results, which might have been caused by confounding factors, including limited sample sizes and different experimental methods. In this review, we lay out the complexity of the GHR isoforms and provide an overview of the major pharmacogenetic research conducted on this ongoing and unresolved subject.

Growth Hormone Dose Modulation and Final Height in Short Children Born Small for Gestational Age: French Real-Life Data

INTRODUCTION

Growth hormone (GH) therapy improves height outcomes in short children born small for gestational age (SGA); however, real-world data on long-term GH exposure are few.

METHODS

We report results from an observational study (NCT01578135) including children born SGA, treated with GH at 126 sites in France, and followed up for >5 years until achieving final adult height (FAH) or until study termination. Primary endpoints were the proportion of patients with normal (>-2) height standard deviation score (SDS) at the last visit and with normal FAH SDS. Post hoc analyses were performed by multivariate logistic regression analysis with stepwise elimination to identify factors associated with GH dose modulation and normal height SDS achievement.

RESULTS

Of 1,408 registered patients, a representative sample (n = 291) was selected for long-term follow-up. At the last visit, 193/291 (66.3%) children achieved normal height SDS and 72/291 (24.7%) reached FAH. FAH SDS was >-2 for chronological age in 48 (66.7%) children and >-2 for adult age in 40 (55.6%) children. In the post hoc analyses, height SDS at the last visit was a significant determinant of whether GH dose had been modulated. Factors significantly associated with reaching normal height SDS were baseline height SDS (taller, better), age at treatment start (younger, better), treatment duration excluding discontinuation periods (longer, better), and absence of a chronic disease. Most (70%) adverse events were non-serious, with 39% considered possibly/probably related to GH treatment.

CONCLUSIONS

GH therapy was fairly effective in most short children born SGA. No new safety concerns were identified.

Early Growth Hormone Initiation Leads to Favorable Long-Term Growth Outcomes in Children Born Small for Gestational Age

CONTEXT

Early initiation of growth hormone (GH) therapy is recommended for short children born small for gestational age (SGA); however, real-world data indicate that treatment is often delayed.

OBJECTIVE

To assess the impact of patient age at GH therapy initiation on long-term growth outcomes and safety in short children born SGA.

METHODS

Analysis of pooled data from NordiNet® International Outcome Study (NCT00960128; 469 European clinics) and the ANSWER Program (NCT01009905; 207 US clinics), two large, complementary observational studies. Patients received GH as prescribed by their treating physician. Enrolled patients born SGA were categorized into three groups based on their age at GH treatment initiation: 2-<4 years, 4-<6 years, and ≥6 years. Patient characteristics at birth and GH initiation, auxology, and safety data were evaluated.

RESULTS

The effectiveness analysis (treatment-naïve and prepubertal patients at GH initiation) included 3,318 patients: 10.7% aged 2-<4 years at therapy initiation, 31.6% aged 4-<6 years, and 57.7% aged ≥6 years. Following 8 years of therapy, the mean improvement in height standard deviation score from baseline was significantly greater in the 2-<4 years group vs the 4-<6 years (+2.5 vs +2.2; P = 0.0054) and ≥6 years groups (+2.5 vs +1.7; P < 0.0001). No unexpected safety events were reported.

CONCLUSION

Early initiation of GH therapy in short children born SGA may be an important contributor to height optimization. The data are reassuring regarding the long-term safety of GH therapy in this population.

The long-term growth, cost-effectiveness, and glycemic effects of growth hormone therapy on children born small for gestational age over 10 years: a retrospective cohort study

OBJECTIVES

We aimed to report our 10-year experience of treating short children born small for gestational age (SGA) by comparing the long-term growth, metabolic safety, and cost-effectiveness of recombinant human growth hormone (rhGH) therapy in short children born SGA with those in rhGH-treated children with growth hormone deficiency (GHD) and Turner syndrome.

METHODS

We performed a 10-year retrospective cohort study at King Saud University Medical City. We included children aged 3-16 years who received rhGH for GHD, SGA, or Turner syndrome for >1 year.

RESULTS

A total of 166 children received rhGH therapy for GHD, 58 for SGA, and 16 for Turner syndrome. During the last study visit, the average height change was 21 cm for GHD children and 14 cm for children born SGA (p-value <0.001). The height SDS change was 0.84 for GHD children and 0.55 for SGA children (p-value=0.004). The average cost-effectiveness ratios for treating GHD and SGA children were USD 1,717.22 and USD 1,157.19 per centimeter gained, respectively. Moreover, the mean incremental cost-effectiveness ratio for GHD vs. SGA patients was USD 2,820.39 per centimeter gained. Dysglycemia developed in 70 patients: 43 (36.44%), 22 (40.74%), and 5 (13%) in the GHD, SGA, and Turner syndrome groups, respectively.

CONCLUSIONS

rhGH is effective in height improvement of short children. However, pursuing rhGH treatment for children born SGA requires a shared decision-making approach to balance the modest benefit of final adult height gain with the long-term metabolic effects, considering the acceptable costs on the Saudi healthcare system.

Long-term effectiveness of growth hormone therapy in children born small for gestational age: An analysis of LG growth study data

Purpose

Growth hormone (GH) treatment has been used to improve growth in short children who were born small for gestational age (SGA). The aim of this study was to investigate the long-term efficacy of GH treatment in these children.

Methods

Data from a multicenter observational clinical trial (ClinicalTrials.gov NCT01604395, LG growth study) were analyzed for growth outcome and prediction model in response to GH treatment. One hundred fifty-two children born SGA were included.

Results

The mean age of patients born SGA was 7.13 ± 2.59 years. Height standard deviation score (SDS) in patients born SGA increased from -2.55 ± 0.49 before starting treatment to -1.13 ± 0.76 after 3 years of GH treatment. Of the 152 patients with SGA, 48 who remained prepubertal during treatment used model development. The equation describing the predicted height velocity during 1st year of GH treatment is as follows: the predictive height velocity (cm) = 10.95 + [1.12 x Height SDS at initial treatment (score)] + [0.03 x GH dose (ug/kg/day)] + [0.30 x TH SDS at initial treatment (score)] + [0.05 x age (year)] + [0.15 x Weight SDS at initial treatment (score)] ± 1.51 cm.

Conclusions

GH treatment improved growth outcome in short children born SGA. We also developed a prediction model that is potentially useful in determining the optimal growth outcome for each child born SGA.

Trial registration

ClinicalTrials.gov Identifier: NCT01604395.

Efficacy and safety of the recombinant human growth hormone in short children born small for gestational age: A randomized, multicentre, comparative phase III trial

OBJECTIVE

Growth hormone (GH) treatment is known to be effective in increasing stature in children with a short stature born small for gestational age (SGA). This multicentre, randomized, open-label, comparative, phase III study aimed to evaluate the efficacy and safety of Growtropin-II (recombinant human GH) and to demonstrate that the growth-promoting effect of Growtropin-II is not inferior to that of Genotropin in children with SGA (NCT ID: NCT02770157).

METHODS

Seventy five children who met the inclusion criteria were randomized into 3 groups in a ratio of 2:2:1 (the study group [Growtropin-II, n = 30], control group [Genotropin, n = 30], and 26-week non-treatment group [n = 15]). The study and control groups received subcutaneous injections of Growtropin-II and Genotropin, respectively for 52 weeks, whereas the non-treatment group underwent a non-treatment observation period during weeks 0 to 26 and a dosing period during weeks 27 to 52 and additional dosing till week 78 only in re-consenting children.

RESULTS

No significant differences in demographic and baseline characteristics between the groups were observed. The mean ± standard deviation change difference in annualized height velocity (aHV) (study group - control group) was 0.65 ±2.12 cm/year (95% confidence interval [CI], -0.53 to 1.83), whereas the lower limit for the 2-sided 95% CI was -0.53 cm/year. Regarding safety, treatment-emergent adverse events (TEAEs) occurred in 53.33% children in the study group and 43.33% children in the control group; the difference in the incidence of TEAEs between the 2 treatment groups was not statistically significant (P  = .4383). A total of 17 serious adverse events (SAEs) occurred in 13.33% children in the treatment groups, and no significant difference in incidence between groups (P  = .7065) was seen. Two cases of adverse drug reaction (ADR) occurred in 2 children (3.33%): 1 ADR (injection site swelling or pain) occurred in 1 child (3.33%) each in the study and control groups.

CONCLUSIONS

This study demonstrates that the change in aHV from the baseline till 52 weeks with Growtropin-II treatment is non-inferior to that with Genotropin treatment in children with short stature born SGA. Growtropin-II is well-tolerated, and its safety profile is comparable with that of Genotropin over a 1-year course of treatment.

Factors influencing growth hormone therapy effect during the prepubertal period in small for gestational age children without catch-up growth

PURPOSE

Because small for gestational age (SGA) children who fail to experience catch-up growth have an increased risk of short stature in adulthood, growth hormone (GH) treatment is recommended for effective growth. In this study, we evaluated the effect of GH treatment during the prepubertal period and analyzed for correlation between GH treatment response and clinical factors in SGA children.

METHODS

A retrospective, single-center study was conducted from 2014 to 2020. A total of 34 prepubertal children of short stature up to 4 years of age and born as SGA were enrolled. We recorded clinical data including birth data, age, weight, height, bone age (BA), and insulin-like growth factor 1 (IGF-1) levels.

RESULTS

The mean gestational age and birth weight were 37.50±2.51 weeks and 2,200.00±546.79 g. At the start of GH treatment, the mean chronological age and BA were 5.54±1.73 years and 4.52±1.85 years, respectively. The height standard deviation score (SDS) (-2.47±0.45) and IGF-1 SDS (0.16±1.57) were calculated. Height velocity was 9.43±1.40 cm during the first GH treatment year and 7.63±1.16 cm during the second year (P<0.05). The treatment growth response was positively correlated with young age (P=0.047) and lower BA (P=0.049) at the start of treatment. In multiple regression analysis, IGF-1 SDS change had a significantly positive association with GH treatment response (P=0.045).

CONCLUSION

GH treatment is effective for short stature SGA children who do not experience catch-up growth. Early initiation of GH treatment improved growth outcomes. As IGF-1 SDS is positively correlated with height SDS, IGF-1 monitoring is important during GH treatment of SGA prepubertal children.

The long-term safety and effectiveness of growth hormone treatment in Japanese children with short stature born small for gestational age

This study aimed to characterize the safety and effectiveness of GH treatments, in usual clinical practice, in children with short stature born small for gestational age (SGA). This was a multicenter, open-label, non-interventional study (NCT01110928) conducted at 150 sites in Japan (2009–2018). The primary objective was to assess the type and frequency of serious adverse drug reactions (SADRs) associated with long-term GH use. Overall, 452 naïve and 46 non-naïve (previously treated) children were enrolled. GH treatment was well‑tolerated, with SADRs occurring in 1.3% (6/452) and 0% (0/46) of naïve and non-naïve children, respectively. No new safety concerns or notable changes in glucose metabolism were identified during long-term treatment. Altogether, 57 children (32 naïve and 25 non-naïve) reached near adult height (NAH). In naïve and non-naïve children, mean ± standard deviation (SD) height standard deviation score (SDS) at NAH were –2.03 ± 0.77 and –1.53 ± 0.81, respectively, representing a change of +0.85 ± 0.72 and +1.24 ± 0.66 from baseline height SDS, respectively. Mean treatment duration to NAH was 4.29 (naïve) and 7.26 (non-naïve) yr. Thus, long-term GH treatment for short stature in children born SGA was confirmed to have a good safety profile and was effective for improving adult height.

Final adult height of children with idiopathic short stature: a multicenter study on GH therapy alone started during peri-puberty

Background

To evaluate the efficacy of GH in improving FAH in ISS children in a multicenter study.

Methods

A real-world observation was carried out. Children with ISS in seven hospitals in China were enrolled. The height gains standard deviation score and the height gain over the target height were evaluated.

Results

There were 344 ISS patients (217 boys and 127 girls). The baseline average age of boys and girls was 12.7 and 11.7 years, with bone age of 11.7 and 10.1 years, respectively. The baseline height SDS of boys and girls was − 3.07 and − 2.74, and the FAH SDS was − 1.91 and − 1.38, respectively. Compared with the baseline height SDS, the FAH SDS was significantly increased in both boys and girls (both P = 0.0000). The FAH SDS was the highest (gain by 1.54 SD) in the ≥2y treatment course group. Two hundred eighteen patients (218/344, 63.4%) had a FAH SDS > − 2 SD. Among these patients, girls in the 1-2y treatment course group and ≥ 2y group had a FAH SDS higher than TH SDS. Even in the control group, a spontaneous catch-up growth of 1.16 SD was observed. A multivariate linear regression model was used to analyze the results, with FAH SDS as the dependent variable. It was found that the treatment course and baseline height SDS in the boys’ model were statistically significant (P < 0.05), whereas the baseline height SDS and baseline bone age significantly affected the girls’ FAH SDS (P < 0.05).

Conclusions

Both girls and boys of ISS improved FAH by GH therapy even if treatments begin over 10 years old and majority of them reached TH. Some peri-puberty ISS will have a spontaneous height gain. We recommend the course of GH treatment more than 2 years for girls, and longer courses for boys.

Effect of growth hormone treatment on children with idiopathic short stature (ISS), idiopathic growth hormone deficiency (IGHD), small for gestational age (SGA) and Turner syndrome (TS) in a tertiary care center

OBJECTIVES

To assess the long-term effect of growth hormone (GH) therapy in a large cohort of short children with different etiologies.

PATIENTS AND METHODS

We evaluated retrospectively the anthropometric data of 252 short children [height SDS <-2: 154 children with growth hormone deficiency (GHD), 63 with idiopathic short stature (ISS), 26 with SGA, and 9 with Turner syndrome (TS)] who were treated, in our center, with GH between 1-2007 and 1-2018. Before and during recombinamt growth-hormone (recGH) treatment, auxological parameters including height (Ht), weight (Wt), Ht - Z score (HtSDS), body mass index (BMI) and BMISDS were recorded every 6 months; bone age (BA) was assessed every 12 months.

RESULTS

At the end of first year of rhGH therapy and after an average of 3 years treatment all groups of short children had significant increase in HtSDS, which was higher in GHD compared to other groups. Children with GHD, SGA, ISS and TS increased their HtSDS by an average of 2.2, 1.46, 0.6 and 0.99 SD, respectively at the end of follow up period (for all groups, p: <0.001). The bone age/chronological age (BA/CA) ratio did not differ significantly among ISS, GHD and SGA groups after GH therapy. The HtSDS gain was higher in children with GHD compared to other ISS, SGA and TS groups (p:< 0.01; p: 0.015 and p: 0.029, respectively).  HtSDS improvement occurred during the first 3 years of rhGH therapy. The BMISDS increased significantly in children with GHD, after 3 years of rhGH therapy (p: < 0.001). After rhGH treatment, the BMISDS decreased significantly in children with ISS and SGA (p: < 0.01 and < 0.001, respectively) but did not change in children with TS (p: 0.199).

CONCLUSIONS

Children with GHD, SGA, ISS and TS exhibited significant increases in HtSDS when treated with rhGH for 3 years. The HtSDS gain was higher in children with GHD compared to other groups.