Attaining genetic height potential: Analysis of height outcomes from the ANSWER Program in children treated with growth hormone over 5 years

Clinical profiles and molecular genetic analyses of 98 Chinese children with short statures

Background

Short stature is one of the most prevalent endocrine disorders in children, and its genetic basis is a complex and actively researched subject. Currently, there is limited genetic research on exome sequencing for short stature, and more large-scale studies are necessary for further exploration.

Methods

The retrospective study entailed investigation of 98 Chinese children with short statures (height SDS ≤ -2.5) of unknown etiologies recruited between 2017 and 2021. Whole-exome sequencing (WES) was performed on these patients to identify the potential genetic etiologies. The clinical data were reviewed retrospectively to assess the pathogenicity of the identified mutations. Additionally, 31 patients consented to and received recombinant human growth hormone (rhGH) therapy for 12 months. The short-term effects of rhGH treatment were evaluated across different etiologies of patients with short statures.

Results

The WES results were used to identify 31 different variants in 18 genes among 24 (24.5%) patients. Individuals with more severe short statures were more likely to have underlying genetic etiologies. Short stature accompanied by other phenotypes had significantly higher diagnostic yields than simple severe short stature. The rhGH therapy demonstrated efficacy in most children. Nevertheless, the treatment response was suboptimal in a boy diagnosed with 3M syndrome.

Conclusion

WES is an important approach for confirming genetic disorders in patients with severe short statures of unknown etiologies, suggesting that it could be used as a primary diagnostic strategy. The administration of rhGH may not be suitable for all children with short statures, and the identification of the genetic cause of short stature by WES has significant guidance value for rhGH treatment.

Auxological and metabolic effects of long-term treatment with recombinant growth hormone in children born small for gestational age: a retrospective study

RATIONALE

Children born small for gestational age (SGA) not showing catch-up during the first two years of life reportedly show an impaired growth rate and adult height, as well as a worse metabolic outcome, mainly in terms of glycemic and lipid profile, compared to general population. In SGA children with short stature, treatment with recombinant growth hormone (GH) is currently recommended until adolescence; therefore, it may last long-term.

STUDY METHODS

The aim of the current study was to evaluate the auxological and metabolic effects and the safety of long-term recombinant GH treatment in SGA children. The study included 15 SGA children (5 F, 10 M; mean age: 6.78 yrs) treated with GH for at least 48 months. Growth and metabolic parameters, including glycemic and lipid profile, transaminases, and urycemia, were collected every six months.

RESULTS

Compared to baseline, SGA children showed a significant improvement in height, weight, and growth rate after four yaers of treatment with GH (p ≤ 0.002), being already evident after six months of treatment (p < 0.001). Noteworthy, patients showed a constant, significant improvement in height throughout the treatment, as it was significantly higher at each follow-up compared to the previous one, until 42 months of treatment, except at 30 months of treatment (p < 0.001 T6VST12; p < 0.01 T12VST18, T18VST24; p < 0.05 T30VST36, T36VST42). Considering metabolic parameters, compared to baseline, a recurring increase in glycemia (p ≤ 0.028 vs T30, T36, and T48) and decrease in AST (p ≤ 0.035 vs T36, T42, and T48) and an occasional decrease in LDL cholesterol (p ≤ 0.04 vs T24 and T42) and triglycerides (p = 0.008 vs T18) and increase in urycemia (p = 0.034 vs T42). Considering safety profile, treatment was well tolerated, as the most frequently reported adverse event was poor compliance (20%); no hyperglycemia, hypercholesterolemia or hyperstransaminasemia occurred throughout the treatment, CONCLUSIONS: Long-term GH treatment showed to be effective in improving height and growth rate in SGA children, with a positive impact of metabolic profile and a safety profile, although glycemia should be carefully monitored over time.

A Superlong-Acting Growth Hormone-Polypeptide Fusion for Growth Hormone Deficiency Treatment

Recombinant human growth hormone (rhGH) is clinically used to treat growth hormone deficiency (GHD). However, daily administration of rhGH is required due to its poor stability and short blood circulation, which causes pains and burdens as well as inconvenience to patients. In this study, a method for genetically fusing rhGH to a thermosensitive polymer of elastin-like polypeptide (ELP) is reported, using which the rhGH-ELP thermosensitive fusion protein can be purified by the thermosensitivity of ELP instead of chromatography. The ELP fusion not only drastically improves the stability of rhGH, but also enables the in situ formation of a sustained-release depot of rhGH-ELP upon subcutaneous (SC) injection, which exhibits gentle release with a platform-to-trough fluctuation in blood and a very long circulatory half-life of 594.6 h. In contrast, rhGH exhibits a peak-to-trough fluctuation in blood with a very short circulatory half-life of 0.7 h. As a result, a single subcutaneous injection of rhGH-ELP can consecutively promote the linear growth of rats and the development of major tissues and organs over 3 weeks without obvious side effects, whereas rhGH is required to be injected daily to achieve similar therapeutic results.

Somatrogon injection for the treatment of pediatric growth hormone deficiency with comparison to other LAGH products

INTRODUCTION

Somatrogon (NGENLA™) is a long-acting GH (LAGH) formulation that was approved in Canada in October 2021 for the treatment of pediatric growth hormone deficiency (GHD). Somatrogon has also received approval in Australia, Japan, the European Union, the USA, and the UK. Somatrogon is a glycoprotein that utilizes three copies of the C-terminal peptide of human chorionic gonadotropin to delay its clearance allowing for once-weekly administration.

AREAS COVERED

The purpose of this article is to describe the development of somatrogon for treatment of individuals with GHD. Trials of somatrogon demonstrated positive efficacy results in adults (Phase 2) and children (Phase 2 and 3) with GHD including non-inferiority of height velocity compared to daily GH, with no concerning side effects. Growth responses, pharmacodynamics and safety data are compared to other LAGH products, lonapegsomatropin and somapacitan, in Phase 3 trials in pediatric GHD.

EXPERT OPINION

New LAGH products, including somatrogon, have the potential to increase patient adherence as well as improve quality of life and clinical outcomes. Clinicians will need to identify the best candidates for LAGH therapy and understand how to safely monitor and adjust therapy. Long-term surveillance studies are necessary to demonstrate adherence, efficacy, cost-effectiveness, and safety of LAGH preparations.

Effects of different doses of long-acting growth hormone in treating children with growth hormone deficiency

BACKGROUND

With the improvement of economy and living standards, the attention paid to short stature in children has been increasingly highlighted. Numerous causes can lead to short stature in children, among which growth hormone deficiency (GHD) is a significant factor.

AIM

To investigate the long-term efficacy and safety of different doses of long-acting polyethylene glycol recombinant human growth hormone (PEG-rhGH) in the treatment of GHD in children.

METHODS

We selected 44 pediatric patients diagnosed with GHD who were treated at Wuhu First People's Hospital from 2014 to 2018. Total 23 patients were administered a high dose of long-acting PEG-rhGH at 0.2 mg/kg subcutaneously each week, forming the high-dose group. Meanwhile, 21 patients were given a lower dose of long-acting PEG-rhGH at 0.14 mg/kg subcutaneously each week, establishing the low-dose Group. The total treatment period was 2 years, during which we monitored the patients' height, annual growth velocity (GV), height standard deviation score (HtSDS), chronological age (CA), bone age (BA), and serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) before treatment and at 6 mo, 1 year, and 2 years after treatment initiation. We also monitored thyroid function, fasting plasma glucose, fasting insulin, and other side effects. Furthermore, we calculated the homeostatic model assessment for insulin resistance.

RESULTS

After 1 year of treatment, the GV, HtSDS, IGF-1, BA, and IGFBP-3 in both groups significantly improved compared to the pre-treatment levels (P < 0.05). Moreover, when comparing GV, HtSDS, IGF-1, BA, and IGFBP-3 between the two groups, there were no statistically significant differences either before or after the treatment (P > 0.05). During the treatment intervals of 0-1.0 years and 1.0-2.0 years, both patient groups experienced a slowdown in GV and a decline in HtSDS improvement (P < 0.05).

CONCLUSION

The use of PEG-rhGH in treating GHD patients was confirmed to be effective, with similar outcomes observed in both the high-dose group and low-dose groups, and no significant differences in the main side effects.

Development of a Minimum Dataset for the Monitoring of Recombinant Human Growth Hormone Therapy in Children with Growth Hormone Deficiency: A GloBE-Reg Initiative

INTRODUCTION

Although there are some recommendations in the literature on the assessments that should be performed in children on recombinant human growth hormone (rhGH) therapy, the level of consensus on these measurements is not clear. The objective of the current study was to identify the minimum dataset (MDS) that could be measured in a routine clinical setting across the world, aiming to minimise burden on clinicians and improve quality of data collection.

METHODS

This study was undertaken by the growth hormone (GH) scientific study group in GloBE-Reg, a new project that has developed a common registry platform that can support long-term safety and effectiveness studies of drugs. Twelve clinical experts from 7 international endocrine organisations identified by the GloBE-Reg Steering Committee, 2 patient representatives, and representatives from 2 pharmaceutical companies with previous GH registry expertise collaborated to develop this recommendation. A comprehensive list of data fields routinely collected by each of the clinical and industry experts for children with growth hormone deficiency (GHD) was compiled. Each member was asked to determine the: (1) importance of the data field and (2) ease of data collection. Data fields that achieved 70% consensus in terms of importance qualified for the MDS, provided <50% deemed the item difficult to collect.

RESULTS

A total of 246 items were compiled and 27 were removed due to redundancies, with 219 items subjected to the grading system. Of the 219 items, 111 achieved at least 70% consensus as important data to collect when monitoring children with GHD on rhGH treatment. Sixty-nine of the 219 items were deemed easy to collect. Combining the criteria of importance and ease of data collection, 63 met the criteria for the MDS. Several anomalies to the MDS rule were identified and highlighted for discussion, including whether the patients were involved in current or previous clinical trials, need for HbA1c monitoring, other past medical history, and adherence, enabling formulation of the final MDS recommendation of 43 items; 20 to be completed once, 14 every 6 months, and 9 every 12 months.

CONCLUSION

In summary, this exercise performed through the GloBE-Reg initiative provides a recommendation of the MDS requirement, collected through real-world data, for the monitoring of safety and effectiveness of rhGH in children with GHD, both for the current daily preparations and the newer long-acting GH.

Long-acting PEGylated growth hormone in children with idiopathic short stature

OBJECTIVE

To evaluate the safety and efficacy of weekly PEGylated-recombinant human growth hormone (PEG-rhGH) in children with idiopathic short stature (ISS) in China.

DESIGN AND METHODS

This was a multicenter, phase II study in which all subjects were randomized 1:1:1 to weekly s.c. injections of PEG-rhGH 0.1 (low-dose (LD) group) or 0.2 mg/kg/week (high-dose (HD) group) or control for 52 weeks. The primary end point was change (Δ) in height s.d. score (HT-SDS) from baseline to week 52. Secondary end points were height velocity (HV), bone maturity, insulin-like growth factor-1 (IGF-1) SDS, and IGF-1/insulin-like growth factor-binding protein-3 (IGFBP-3) molar ratio.

RESULTS

A total of 360 children with ISS were recruited in the study (n = 120 in each group). At week 52, ΔHT-SDS was 0.56 ± 0.26, 0.98 ± 0.35, and 0.20 ± 0.26 in the LD, HD, and control groups, respectively (within-group P < 0.0001; intergroup P < 0.0001). Statistically significant values of ΔHV, IGF-1, IGF-1/IGFBP-3 ratio, and IGF-1 SDS at week 52 from baseline were observed in both treatment groups (P < 0.0001). There were clear dose-dependent responses for all auxological variables. PEG-rhGH was well tolerated throughout the treatment period with treatment-emergent adverse events (TEAEs) reported in 86.5%, 84.6%, and 91.3% of children in the HD, LD, and control groups, respectively. The incidence of TEAEs was similar in all treatment groups despite the difference in doses. A total of 27 (8.7%) children experienced drug-related TEAEs.

CONCLUSION

Fifty-two-week treatment with PEG-rhGH 0.1 or 0.2 mg/kg/week achieved significant improvement in HT-SDS and other growth-related variables, including HV, IGF-1 SDS, and IGF-1/IGFBP-3 ratio, in a dose-dependent manner. Both doses were well tolerated with similar safety profiles.

Hsa_circ_0008870 suppresses bone formation of growth plate through inhibition of miR-185-3p/ MAPK1 axis in idiopathic short stature

Idiopathic short stature (ISS) is the most common clinical cause of the short stature with an unclear aetiology and a lack of effective treatment. Circular RNAs have been shown to play a significant regulatory role through various signal transduction pathways in a variety of diseases in recent years. However, the role of circular RNAs on ISS is not yet well-understood and requires a special attention. The differentially expressed circular RNAs were screened by microarray chip analysis, and RT-qPCR was used to verify the expression of hsa_circ_0008870 in ISS patients. Subsequently, in vitro and in vivo experiments were conducted to determine the biological functions of hsa_circ_0008870 in ISS. The authors first confirmed that hsa_ circ_0008870 was downregulated in ISS children. Meanwhile, we also observed that the downregulated hsa_circ _0008870 significantly inhibited chondrocyte proliferation and endochondral ossification in vivo and in vitro. Mechanistically, hsa_circ_0008870 regulates MAPK1 expression by sponge miR-185-3p. This mechanism of action was further verified through rescue experiments. Finally, the authors revealed that the silencing of hsa_circ_0008870 induces low expression of MAPK1 by impairing the sponge action of miR-185-3p, thereby inhibiting chondrocyte proliferation, hypertrophy, and endochondral ossification, which results in a short stature phenotype. In addition to these, we also observed an interesting phenomenon that upregulated of miR-185-3p can in turn inhibit the expression of hsa_circ_0008870 in chondrocytes. This suggests that hsa_circ_0008870 could potentially serve as a therapeutic target for the treatment of ISS.

Spotlight on Lonapegsomatropin Once-Weekly Injection and Its Potential in the Treatment of Growth Hormone Deficiency in Pediatric Patients

Lonapegsomatropin, a long-acting GH therapy (LAGH), was approved by the United States Food and Drug Administration in August 2021 for the treatment of pediatric growth hormone deficiency (GHD). Lonapegsomatropin is a prodrug consisting of unmodified GH transiently conjugated to methoxypolyethylene glycol which enables time-release of GH with a half-life of ~25 hours allowing for once-weekly administration. Clinical trials of lonapegsomatropin have demonstrated positive efficacy results in children (phase 2 and 3) and adults (phase 2) with GHD. The phase 3 trial in children with GHD established non-inferiority and statistical superiority of height velocity with lonapegsomatropin (11.2 cm/yr) compared to daily GH (10.3 cm/yr), with no concerning side effects with lonapegsomatropin. Similar growth responses have been reported in other LAGH products in phase 2 (somapacitan) and phase 3 (somatrogon) trials. Lonapegsomatropin is distributed in temperature-stable, prefilled cartridges at 9 different doses that can be prescribed based upon specific weight brackets designed to deliver approximately 0.24 mg/kg/wk. An electronic delivery device is required to combine the powdered medication with the diluent and deliver the medication subcutaneously through a small gauge needle to the recipient. The pharmacodynamic data from the clinical trials of lonapegsomatropin has been used to develop models to estimate an average IGF-1 value drawn at any time during the weekly injection interval. This average IGF-1 value may be used to for safety monitoring and/or to guide dose adjustment. New LAGH products, including lonapegsomatropin, may potentially improve patient adherence, quality of life and clinical outcomes, particularly in patients with poor adherence to daily GH injections in the future. With the availability of new LAGH products, clinicians will need to identify the best candidates for LAGH therapy and understand how to monitor and adjust therapy. Long-term surveillance studies are needed to demonstrate adherence, efficacy, cost-effectiveness and safety of LAGH preparations.

Growth hormone treatment does not to lead to insulin resistance nor excessive rise in IGF-1 levels, while improving height in patients small for gestational age A long-term observational study

OBJECTIVE

In children born small for gestational age (SGA), the relationship between growth hormone (GH) treatment and insulin resistance (IR) has only been investigated for a short period, necessitating a longer observation period. This study aimed to evaluate the long-term (10 years) effect of GH to SGA-children on IR and safety during treatment.

DESIGN

This was a multicenter observational study.

PATIENTS

SGA-children who received GH treatment in Spain (stratified by Tanner-stage and age at GH onset [two groups: ≤6 years old or >6 years old]).

MEASUREMENTS

The analysed variables (yearly measures) included auxologic, metabolic (insulin-like growth factor-1 (IGF-1), height velocity [HV], weight and homeostatic model assessment-IR [HOMA-IR]) and safety data. Data were collected prospectively (since the study approval: 2007) and retrospectively (since the initiation of GH treatment: 2005-2007).

RESULTS

A total of 389 SGA children (369 Tanner-I) were recruited from 27 centres. The mean age (standard deviation) of the children at GH treatment onset was 7.2 (2.8) years old. IGF-1 (standard deviation score [SDS]) and HOMA-IR values tended to increase until the sixth year of GH-treatment, with significant differences being observed only during the first year, while these remained stable in the later years (within normal ranges). Height (SDS) increased significantly (basal: -3.0; tenth year: -1.13), and the maximum HV (SDS) occurred during the first year (2.75 ± 2.39).

CONCLUSIONS

HOMA-IR values increased significantly in SGA-children during the first year of GH-treatment, remained stable and were within normal ranges in all cases. Our 10-year data suggests that long-term GH treatment does not promote IR and is well-tolerated, safe and effective.

A Randomized Controlled Phase 3 Study on the Efficacy and Safety of Recombinant Human Growth Hormone in Children With Idiopathic Short Stature

BACKGROUND

To evaluate the safety and efficacy of daily somatropin (Jintropin^®), a recombinant human growth hormone, in prepubertal children with ISS in China.

METHODS

This study was a multicenter, randomized, controlled, open-label, phase 3 study. All subjects were randomized 3:1 to daily somatropin 0.05 mg/kg/day or no treatment for 52 weeks. A total of 481 subjects with a mean baseline age of 5.8 years were enrolled in the study. The primary endpoint was change in (△) height standard deviation score (HT-SDS) for chronological age (CA). Secondary endpoints included △height from baseline; △bone age (BA)/CA; △height velocity (HV) and △insulin-like growth factor 1 (IGF-1 SDS).

RESULTS

△HT-SDS at week 52 was 1.04 ± 0.31 in the treatment group and 0.20 ± 0.33 in the control group (P < 0.001). At week 52, statistical significance was observed in the treatment group compared with control for △height (10.19 ± 1.47 cm vs. 5.85 ± 1.80 cm; P < 0.001), △BA/CA (0.04 ± 0.09 vs. 0.004 ± 0.01; P < 0.001), △HV (5.17 ± 3.70 cm/year vs. 0.75 ± 4.34 cm/year; P < 0.001), and △IGF-1 SDS (2.31 ± 1.20 vs. 0.22 ± 0.98; P < 0.001). The frequencies of treatment-emergent adverse events (TEAEs) were similar for the treatment and the control groups (89.8% vs. 82.4%); most TEAEs were mild to moderate in severity and 23 AEs were considered study-drug related.

CONCLUSIONS

Daily subcutaneous administration of somatropin at 0.05 mg/kg/day for 52 weeks demonstrated improvement in growth outcomes and was well tolerated with a favorable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03635580). URL: https://clinicaltrials.gov/ct2/show/NCT03635580.

What do we do now that the long-acting growth hormone is here?

In standard 52-week phase III clinical trials, once weekly lonapegsomatropin, somatrogon and somapacitan have been found to yield non-inferior height velocities and similar safety profiles to daily GH (DGH) in children with pediatric growth hormone deficiency (PGHD). Lonapegsomatropin, a long-acting GH therapy (LAGH), was approved by the United States Food and Drug Administration (FDA) in August 2021 for the treatment of PGHD and has also been approved in other regions of the world. Somatrogon was approved for the treatment of PGHD beginning in some regions beginning in late 2021. Somapacitan was approved by the FDA for the treatment of Adult GHD in August 2020. The phase III clinical trial of somapacitan for the treatment of PGHD has been completed and demonstrated non-inferiority of somapacitan to DGH. New LAGH products may improve patient adherence, quality of life and clinical outcomes, particularly in patients with poor adherence to daily GH injections in the future. With the availability of new LAGH products, clinicians will need to identify the best candidates for LAGH therapy and understand how to monitor and adjust therapy. Long-term surveillance studies are needed to demonstrate adherence, efficacy, cost-effectiveness and safety of LAGH preparations and to understand how the non-physiological pharmacokinetic and pharmacodynamic profiles following administration of each LAGH product relate to short- and long-term safety and efficacy of LAGH therapy.

An eHealth Framework for Managing Pediatric Growth Disorders and Growth Hormone Therapy

Background

The use of technology to support health and health care has grown rapidly in the last decade across all ages and medical specialties. Newly developed eHealth tools are being implemented in long-term management of growth failure in children, a low prevalence pediatric endocrine disorder.

Objective

Our objective was to create a framework that can guide future implementation and research on the use of eHealth tools to support patients with growth disorders who require growth hormone therapy.

Methods

A total of 12 pediatric endocrinologists with experience in eHealth, from a wide geographical distribution, participated in a series of online discussions. We summarized the discussions of 3 workshops, conducted during 2020, on the use of eHealth in the management of growth disorders, which were structured to provide insights on existing challenges, opportunities, and solutions for the implementation of eHealth tools across the patient journey, from referral to the end of pediatric therapy.

Results

A total of 815 responses were collected from 2 questionnaire-based activities covering referral and diagnosis of growth disorders, and subsequent growth hormone therapy stages of the patient pathway, relating to physicians, nurses, and patients, parents, or caregivers. We mapped the feedback from those discussions into a framework that we developed as a guide to integration of eHealth tools across the patient journey. Responses focused on improved clinical management, such as growth monitoring and automation of referral for early detection of growth disorders, which could trigger rapid evaluation and diagnosis. Patient support included the use of eHealth for enhanced patient and caregiver communication, better access to educational opportunities, and enhanced medical and psychological support during growth hormone therapy management. Given the potential availability of patient data from connected devices, artificial intelligence can be used to predict adherence and personalize patient support. Providing evidence to demonstrate the value and utility of eHealth tools will ensure that these tools are widely accepted, trusted, and used in clinical practice, but implementation issues (eg, adaptation to specific clinical settings) must be addressed.

Conclusions

The use of eHealth in growth hormone therapy has major potential to improve the management of growth disorders along the patient journey. Combining objective clinical information and patient adherence data is vital in supporting decision-making and the development of new eHealth tools. Involvement of clinicians and patients in the process of integrating such technologies into clinical practice is essential for implementation and developing evidence that eHealth tools can provide value across the patient pathway.

Outcomes in children treated with growth hormone for Prader-Willi syndrome: data from the ANSWER Program® and NordiNet® International Outcome Study

Background

Growth hormone (GH) deficiency is common in patients with Prader-Willi syndrome (PWS) and leads to short adult stature. The current study assessed clinical outcomes based on real-world observational data in pediatric patients with PWS who were treated with GH.

Methods

Data from patients previously naïve to treatment with GH who began therapy with somatropin were collected from 2006 to 2016 in the observational American Norditropin® Studies: Web-Enabled Research (ANSWER) Program® and NordiNet® International Outcome Study. Variables affecting change from baseline in height standard deviation scores (HSDS; n = 129) and body mass index standard deviation scores (BMI SDS; n = 98) were determined.

Results

Patients included in both HSDS and BMI SDS analyses were treated with a mean GH dose of 0.03 mg/kg/d (SD, 0.01 mg/kg/d). Results from the HSDS analysis revealed that baseline age and years on treatment had a significant impact on the change in HSDS. In the BMI SDS analysis, longer GH treatment time led to a greater change in BMI SDS from baseline, and patients with a higher BMI at the start of treatment had a greater decrease in BMI over time.

Conclusions

GH is effective in the management of children with PWS. Earlier treatment resulted in a greater gain in height, and a longer treatment period resulted in better outcomes for both height and BMI.

Trial registration

This study was registered with ClinicalTrials.gov (NCT01009905) on November 9, 2009.

Height outcomes in children with growth hormone deficiency and idiopathic short stature treated concomitantly with growth hormone and aromatase inhibitor therapy: data from the ANSWER program

Background

Treatment of children with growth hormone deficiency (GHD) or idiopathic short stature (ISS) using GH is only effective for bone growth prior to epiphyseal fusion. Aromatase inhibitor therapy (AIT) blocks estrogen production, thereby delaying epiphyseal fusion. The current study analyzed baseline characteristics and longitudinal data of male patients with GHD or ISS who were treated with GH and concomitant AIT.

Methods

Data were obtained from the observational American Norditropin® Studies: Web-Enabled Research (ANSWER) Program, which collected efficacy and safety data of patients treated with Norditropin®. A longitudinal cohort approach compared patient characteristics, including chronologic age, bone age, and height standard deviation score (HSDS), in GH-treated males before and after AIT initiation.

Results

A total of 142 GH-naïve patients with GHD (n = 115) or ISS (n = 27) with mean (± SD) baseline chronological ages of 12.10 ± 3.00 and 10.76 ± 3.07 years, respectively, were analyzed. The majority were classified at advanced Tanner stages II to V. Patients with GHD had mean HSDS of − 1.97 ± 0.78 at baseline and − 0.99 ± 0.88 prior to AIT initiation, while corresponding values for patients with ISS were − 2.15 ± 0.72 and − 1.04 ± 0.79, respectively. In patients evaluated after 2 years of concomitant AIT, mean HSDS had decreased to − 0.40 ± 1.16 and − 0.65 ± 0.52 for patients with GHD and ISS, respectively. Patients with GHD had a mean bone age/chronological age ratio (BA/CA) of 0.91 ± 0.11 at baseline and 0.97 ± 0.10 prior to AIT initiation, while corresponding values for patients with ISS were 0.85 ± 0.16 and 0.99 ± 0.10, respectively. In patients evaluated after 2 years of concomitant AIT, mean BA/CA values were 0.95 ± 0.10 and 0.96 ± 0.06 for patients with GHD and ISS, respectively.

Conclusions

In this real-world analysis, use of AIT with GH in males appeared to be associated with ongoing growth over 2 years, and AIT likely augmented growth potential as indicated by continued HSDS increase with decreased BA/CA after AIT initiation.

Trial registration

This trial was sponsored by Novo Nordisk and is registered with ClinicalTrials.gov (NCT01009905). Registered November 11, 2009; retrospectively registered

Combined therapy with GnRH analogue and growth hormone increases adult height in children with short stature and normal pubertal onset

OBJECTIVE

To investigate whether gonadotropin releasing hormone analogue (GnRHa) combined with recombinant human growth hormone (rhGH) can improve the adult height (AHt) of children with short stature and normal pubertal onset.

METHODS

In this retrospective study, GnRHa/rhGH treatment was given to children with normal pubertal onset and short stature. Patients were followed up to measure their AHt. The primary outcomes were the disparity between AHt standard deviation score (AHt SDS) and pre-treatment height standard deviation score (Ht SDS) and the disparity between AHt and target height (THt).

RESULTS

A total of 94 patients were included. Forty-nine boys were treated with GnRHa/rhGH for 24.84 ± 13.01 months, and 45 girls were treated for 23.89 ± 10.43 months. (2) Before treatment, the Ht SDS of boys and girls was -1.82 ± 1.30 and -1.10 ± 1.61, respectively, and the target height was 168.98 ± 3.51 cm and 157.90 ± 3.25 cm, respectively. (3) After treatment, for boys, the AHt SDS increased by 1.37 ± 1.28 (p = 0.000) and the disparity between AHt and THt was 0.98 ± 6.18 cm (p = 0.273); for girls, the AHtSDS increased by 1.28 ± 1.48 (p = 0.000), and the disparity between AHt and THt was 3.64 ± 4.86 cm (n = 45, p = 0.000). (4) Subgroup analysis showed that, for boys with idiopathic short stature (ISS) and non-ISS, AHt SDS increased by 2.00 ± 1.16 (p = 0.000) and 0.71 ± 1.06 (p = 0.003) respectively, compared with the pre-treatment HtSDS; The disparities between AHt and THt were -0.70 ± 6.54 cm and 2.73 ± 5.37 cm respectively. For girls with ISS and non-ISS, AHtSDS increased by 2.73 ± 1.21 (p = 0.000) and 0.748 ± 1.19 (p = 0.001), respectively; AHt increased by 2.63 ± 6.12 cm (p = 0.165) and 4.02 ± 4.37 cm (p = 0.000) compared with THt, respectively. (5) Multiple linear regression analysis showed that the baseline bone age (BA) (β = -0.200, p = 0.003), basal IGF-1(β = -0.002, p = 0.008) and HtSDS (β = -0.679, p = 0.000) had negative effects on increment of AHtSDS.

CONCLUSION

For adolescents with normal pubertal onset and short stature, with or without ISS, GnRHa/rhGH therapy can effectively improve AHtSDS. After treatment, ISS adolescents can reach the THts, and Non-ISS adolescents can exceed their THts.

The Actions of IGF-1 in the Growth Plate and Its Role in Postnatal Bone Elongation

PURPOSE OF REVIEW

Bone elongation is a complex process driven by multiple intrinsic (hormones, growth factors) and extrinsic (nutrition, environment) variables. Bones grow in length by endochondral ossification in cartilaginous growth plates at ends of developing long bones. This review provides an updated overview of the important factors that influence this process.

RECENT FINDINGS

Insulin-like growth factor-1 (IGF-1) is the major hormone required for growth and a drug for treating pediatric skeletal disorders. Temperature is an underrecognized environmental variable that also impacts linear growth. This paper reviews the current state of knowledge regarding the interaction of IGF-1 and environmental factors on bone elongation. Understanding how internal and external variables regulate bone lengthening is essential for developing and improving treatments for an array of bone elongation disorders. Future studies may benefit from understanding how these unique relationships could offer realistic new approaches for increasing bone length in different growth-limiting conditions.

Long-Acting Growth Hormone Preparations - Current Status and Future Considerations

CONTEXT

Long-acting GH (LAGH) preparations are currently being developed in an attempt to improve adherence. The profile of GH action following administration of LAGH raises practical questions about clinical monitoring and long-term safety and efficacy of these new therapeutic agents.

METHODS

Recent literature and meeting proceedings regarding LAGH preparations are reviewed.

RESULTS

Multiple LAGH preparations are currently at various stages of development, allowing for decreased GH injection frequency from daily to weekly, biweekly, or monthly. Following administration of LAGH, the serum peak and trough GH and IGF-I levels vary depending upon the mechanism used to prolong GH action. Randomized, controlled clinical trials of some LAGH preparations have reported non-inferiority compared with daily recombinant human GH (rhGH) for improved growth velocity and body composition in children and adults with GH deficiency (GHD), respectively. No significant LAGH-related adverse events have been reported during short-term therapy.

CONCLUSION

Multiple LAGH preparations are proceeding through clinical development with some showing promising evidence of short-term clinical efficacy and safety in children and adults with GHD. The relationship of transient elevations of GH and IGF-I following administration of LAGH to efficacy and safety remain to be elucidated. For LAGH to replace daily rhGH in the treatment of individuals with GHD, a number of practical questions need to be addressed including methods of dose adjustment, timing of monitoring of IGF-I, safety, efficacy, and cost-effectiveness. Long-term surveillance of efficacy and safety of LAGH preparations will be needed to answer these clinically relevant questions.

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.

Postnatal management of growth failure in children born small for gestational age

OBJECTIVES

To discuss the etiology and growth consequences of small size at birth and the indications, effects, and safety of biosynthetic growth hormone therapy in children born small for gestational age.

SOURCE OF DATA

A comprehensive and non-systematic search was carried out in the PubMed, LILACS, and SciELO databases from 1980 to the present day, using the terms "small for gestational age," "intrauterine growth restriction," and "growth hormone". The publications were critically selected by the authors.

DATA SYNTHESIS

Although the majority of children born small for gestational age show spontaneous catch-up growth during the first two years of life, some of them remain with short stature during childhood, with high risk of short stature in adult life. Treatment with growth hormone might be indicated, preferably after 2-4 years of age, in those small for gestational age children who remain short, without catch-up growth. Treatment aims to increase growth velocity and to reach a normal height during childhood and an adult height within target height. Response to growth hormone treatment is variable, with better growth response during the pre-pubertal period.

CONCLUSIONS

Treatment with growth hormone in short children born small for gestational age is safe and effective to improve adult height. Efforts should be done to identify the etiology of small size at birth before treatment.

Growth Hormone Treatment for Short Stature in the USA, Germany and France: 15 Years of Surveillance in the Genetics and Neuroendocrinology of Short-Stature International Study (GeNeSIS)

BACKGROUND/AIMS

To describe characteristics, auxological outcomes and safety in paediatric patients with growth disorders treated with growth hormone (GH), for cohorts from the USA, Germany and France enrolled in GeNeSIS, a post-authorisation surveillance programme.

METHODS

Diagnosis and biochemical measurement data were based on reporting from, and GH treatment was initiated at the discretion of, treating physicians. Auxological outcomes during the first 4 years of GH treatment and at near-adult height (NAH) were analysed. Serious and treatment-emergent adverse events were described.

RESULTS

Children in the USA (n = 9,810), Germany (n = 2,682) and France (n = 1,667) received GH (dose varied between countries), most commonly for GH deficiency. Across diagnostic groups and countries, mean height velocity standard deviation score (SDS) was > 0 and height SDS increased from baseline during the first 4 years of treatment, with greatest improvements during year 1. Most children achieved NAH within the normal range (height SDS >-2). No new or unexpected safety concerns were noted.

CONCLUSION

GH treatment improved growth indices to a similar extent for patients in all three countries despite variations in GH doses. Data from these three countries, which together contributed > 60% of patients to GeNeSIS, indicated no new safety signals and the benefit-risk profile of GH remains unchanged.

Efficacy and safety of recombinant human growth hormone in treating Chinese children with idiopathic short stature

OBJECTIVE

This study aims to investigate the efficacy and safety of recombinant human growth hormone (rhGH) in the treatment of idiopathic short stature (ISS).

METHODS

The data of 200 ISS children, who were treated with rhGH from January 2008 to December 2016, were collected and retrospectively analyzed. The data of height, bone age(BA), chronological age(CA), fasting blood glucose, fasting insulin, thyroid function and IGF-1 were collected, and annual growth velocity (GV), height standard deviation score (HtSDS) and related factors that affect GV were statistically analyzed.

RESULTS

(1) GV and HtSDS changes: As the time of treatment increased, the GV decreased year by year. The GV in the second year was significantly lower than that in the first year (P < .0001), and the GV in the fourth year was significantly lower than that in the third year (P < .05). HtSDS gradually increased from the first year to the third year, and became significantly higher than that in the year before the treatment (P < .01). The difference in the increase in HtSDS between the fourth year and third year was not statistically significant (P > .05). (2) The influence factors of GV included age at initial treatment, IGF-1SDS during treatment and GV in the year before treatment. (3) The most common side effects during treatment included transient hyperglycemia and temporary hyperinsulinemia, and these returned to normal after the treatment was stopped. Some patients presented with accelerated bone age growth after two years of treatment (annual growth of bone age △BA was >2 years), compared with children without accelerated bone age growth, and the difference between BA and CA (BA-CA) was significantly reduced at the beginning of the treatment (P < .01).

CONCLUSION

rhGH has a good growth promoting effect on ISS children. A variety of factors may affect the GV, and related adverse reactions should be monitored during the treatment.

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

Growth hormone (GH) is used to treat short stature and growth failure associated with growth disorders. Birth size and GH status variably modulate response to GH therapy. The aim of this study was to determine the effect of birth size on response to GH therapy, and to determine the impact of GH status in patients born small for gestational age (SGA) on response to GH therapy. Data from the prospective, non-interventional American Norditropin® Studies: Web-Enabled Research (ANSWER) Program were analyzed for several growth outcomes in response to GH therapy over 3 years. GH-naïve children from the ANSWER Program were included in this analysis: SGA with peak GH ≥10 ng/mL (20 mIU/l), SGA with peak GH <10 ng/mL (20 mIU/l), isolated growth hormone deficiency (IGHD) born SGA, IGHD not born SGA, and idiopathic short stature. For patients with IGHD, those who did not meet criteria for SGA at birth showed greater improvements in height SDS and BMI SDS than patients with IGHD who met criteria for SGA at birth. For patients born SGA, response to GH therapy varied with GH status. Therefore, unlike previous guidelines, we recommend that GH status be established in patients born SGA to optimize GH therapy.

A genetic approach to evaluation of short stature of undetermined cause

Short stature is a common presentation to paediatric endocrinologists. After exclusion of major endocrine or systemic disease, most children with short stature are diagnosed based on a description of their growth pattern and the height of their parents (eg, familial short stature). Height is a polygenic trait and genome-wide association studies have identified many of the associated genetic loci. Here we review the application of genetic studies, including copy number variant analysis, targeted gene panels, and whole-exome sequencing in children with idiopathic short stature. We estimate 25-40% of children diagnosed with idiopathic short stature could receive a molecular diagnosis using these technologies. A molecular diagnosis for short stature is important for affected individuals and their families and might inform treatment decisions surrounding use of growth hormone or insulin-like growth factor 1 therapy.

Growth hormone in combination with leuprorelin in pubertal children with idiopathic short stature

OBJECTIVE

There is a scarcity of data from randomised controlled trials on the association of growth hormone (GH) with gonadotrophin-releasing hormone agonists in idiopathic short stature (ISS), although this off-label use is common. We aimed to test whether delaying pubertal progression could increase near-adult height (NAH) in GH-treated patients with ISS.

METHODS

Patients with ISS at puberty onset were randomised to GH with leuprorelin (combination, n = 46) or GH alone (n = 45). NAH standard deviation score (SDS) was the primary outcome measure. The French regulatory authority requested premature discontinuation of study treatments after approximately 2.4 years; patients from France were followed for safety.

RESULTS

Mean (s.d.) baseline height SDS was -2.5 (0.5) in both groups, increasing at 2 years to -2.3 (0.6) with combination and -1.8 (0.7) with GH alone. NAH SDS was -1.8 (0.5) with combination (n = 19) and -1.9 (0.8) with GH alone (n = 16). Treatment-emergent adverse events and bone fractures occurred more frequently with combination than GH alone.

CONCLUSION

Due to premature discontinuation of treatments, statistical comparison of NAH SDS between the two cohorts was not possible. During the first 2-3 years of treatment, patients treated with the combination grew more slowly than those receiving GH alone. However, mean NAH SDS was similar in the two groups. No new GH-related safety concerns were revealed. A potentially deleterious effect of combined treatment on bone fracture incidence was identified.

The rationale and design of TransCon Growth Hormone for the treatment of growth hormone deficiency

The fundamental challenge of developing a long-acting growth hormone (LAGH) is to create a more convenient growth hormone (GH) dosing profile while retaining the excellent safety, efficacy and tolerability of daily GH. With GH receptors on virtually all cells, replacement therapy should achieve the same tissue distribution and effects of daily (and endogenous) GH while maintaining levels of GH and resulting IGF-1 within the physiologic range. To date, only two LAGHs have gained the approval of either the Food and Drug Administration (FDA) or the European Medicines Agency (EMA); both released unmodified GH, thus presumably replicating distribution and pharmacological actions of daily GH. Other technologies have been applied to create LAGHs, including modifying GH (for example, protein enlargement or albumin binding) such that the resulting analogues possess a longer half-life. Based on these approaches, nearly 20 LAGHs have reached various stages of clinical development. Although most have failed, lessons learned have guided the development of a novel LAGH. TransCon GH is a LAGH prodrug in which GH is transiently bound to an inert methoxy polyethylene glycol (mPEG) carrier. It was designed to achieve the same safety, efficacy and tolerability as daily GH but with more convenient weekly dosing. In phase 2 trials of children and adults with growth hormone deficiency (GHD), similar safety, efficacy and tolerability to daily GH was shown as well as GH and IGF-1 levels within the physiologic range. These promising results support further development of TransCon GH.

Impact of the underlying etiology of growth hormone deficiency on serum IGF-I SDS levels during GH treatment in children

CONTEXT

Regular monitoring of serum IGF-I levels during growth hormone (GH) therapy has been recommended, for assessing treatment compliance and safety.

OBJECTIVE

To investigate serum IGF-I SDS levels during GH treatment in children with GH deficiency, and to identify potential determinants of these levels.

DESIGN, PATIENTS AND METHODS

This observational cohort study included all patients (n = 308) with childhood-onset non-acquired or acquired GH deficiency (GHD) included in the database of a single academic pediatric care center over a period of 10 years for whom at least one serum IGF-I SDS determination during GH treatment was available. These determinations had to have been carried out centrally, with the same immunoradiometric assay. Serum IGF-I SDS levels were determined as a function of sex, age and pubertal stage, according to our published normative data.

RESULTS

Over a median of 4.0 (2-5.8) years of GH treatment per patient, 995 serum IGF-I SDS determinations were recorded. In addition to BMI SDS, height SDS and GH dose (P < 0.01), etiological group (P < 0.01) had a significant effect on serum IGF-I SDS levels, with patients suffering from acquired GHD having higher serum IGF-I SDS levels than those with non-acquired GHD, whereas sex, age, pubertal stage, treatment duration, hormonal status (isolated GHD (IGHD) vs multiple pituitary hormone deficiency (MPHD)) and initial severity of GHD, had no effect.

CONCLUSIONS

These original findings have important clinical implications for long-term management and highlight the need for careful and appropriate monitoring of serum IGF-I SDS and GH dose, particularly in patients with acquired GHD, to prevent the unnecessary impact of potential comorbid conditions.

Skeletal effects of growth hormone and insulin-like growth factor-I therapy

The growth hormone/insulin-like growth factor (GH/IGF) axis is critically important for the regulation of bone formation, and deficiencies in this system have been shown to contribute to the development of osteoporosis and other diseases of low bone mass. The GH/IGF axis is regulated by a complex set of hormonal and local factors which can act to regulate this system at the level of the ligands, receptors, IGF binding proteins (IGFBPs), or IGFBP proteases. A combination of in vitro studies, transgenic animal models, and clinical human investigations has provided ample evidence of the importance of the endocrine and local actions of both GH and IGF-I, the two major components of the GH/IGF axis, in skeletal growth and maintenance. GH- and IGF-based therapies provide a useful avenue of approach for the prevention and treatment of diseases such as osteoporosis.