Long-term safety and efficacy of daily recombinant human growth hormone treatment in Japanese short children born small for gestational age: final report from an open and multi-center study

Intact FGF23 concentration in healthy infants, children, and adolescents, and diagnostic usefulness in patients with X-linked hypophosphatemic rickets

OBJECTIVE

FGF23 measurement may have a diagnostic role to investigate patients with phosphate disorders. However, normal values for infants, children, and adolescents have not been defined.

METHODS

In a total of 282 (males 145, females 137) healthy infants (n = 30), prepubertal (n = 147), pubertal (n = 59), and postpubertal (n = 46), and in twenty patients with X-linked hypophosphatemic rickets (XLH, age 10.2 ± 5.6 years) serum phosphate (automated analyzer), and plasma intact FGF23 (immunochemiluminescent sandwich assay, DiaSorin) concentrations were measured.

RESULTS

Intact FGF23 concentrations were higher in healthy infants than in prepubertal (P < 0.01) and postpubertal subjects (P < 0.05); pubertal subjects showed higher values (P < 0.05) than postpubertal subjects. Serum phosphate concentrations were higher (P < 0.001) in healthy infants than in prepubertal, pubertal, and postpubertal subjects. Pubertal subjects had higher (P < 0.001) serum phosphate concentrations than postpubertal subjects. Intact FGF23 and serum phosphate concentrations did not differ (P = NS) by sex, age of menarche, and time after menarche. In healthy subjects, there was no correlation between intact FGF23 and serum phosphate concentrations. Intact FGF23 concentrations were higher (P < 0.0001) in patients with XLH than in healthy subjects according to chronological age and pubertal development. In all patients, intact FGF23 concentrations were above 40 pg/mL; intact FGF23 concentrations were inversely correlated with serum phosphate concentrations (r = -0.65; P < 0.01).

CONCLUSION

In healthy subjects, chronological age and puberty were main determinants of intact FGF23 concentrations. Intact FGF23 concentrations may be a useful marker for the early diagnosis of XLH in pediatric patients.

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.

Factors Related to Treatment Non-Adherence Among Caregivers of Pediatric and Adolescent Growth Hormone Deficiency Patients in Japan

Background

About one-third of caregivers of pediatric or adolescent growth hormone deficiency (pGHD) patients in Japan have reported poor treatment adherence. However, few studies have examined factors related to adherence for that group.

Objective

The aim of this study is to consider factors related to poor adherence to daily treatment among caregivers of pGHD patients in Japan.

Methods

A cross-sectional survey was conducted among caregivers of pGHD patients in Japan. Caregivers were asked about demographic and treatment characteristics, health literacy, treatment satisfaction, opinions about treatment, and treatment adherence. Health literacy was assessed using the 14-item health literacy scale (HLS-14). Adherence was assessed using the 8-item Morisky Medication Adherence Scale (MMAS-8). Statistical association with adherence was considered using Chi-square and Student's t-testing. An exploratory factor analysis (EFA) and K-means cluster analysis was conducted to consider the influence of treatment satisfaction and opinions concerning treatment on adherence.

Results

Responses were collected from 112 caregivers. The caregiver's age being 30-39 years old, the primary caregiver being male, the primary caregiver being employed, and low functional health literacy for the caregiver were associated with poor adherence. Patients being pre-elementary school age was also associated with poor adherence. Low satisfaction with drug treatment and/or their device and communication with healthcare professionals (HCPs), and lack of agreement with the importance of treatment management (eg, keeping injection records, getting informed about the disease/therapy, reporting non-adherence, and sticking to an administration schedule), were also associated with poor adherence.

Conclusion

Strategies to improve treatment adherence among caregivers of pGHD patients in Japan should consider the age, gender, and employment status of the caregiver - as well as their functional literacy. Improvement in satisfaction with the drug or device used, better communication with HCPs, and greater awareness of the importance of treatment management, may also lead to better adherence.

Long-Term Efficacy and Safety of Recombinant Human Growth Hormone in Children Born Small for Gestational Age

There is a lack of long-term data on the benefit of growth hormone (GH) treatment in Chinese children born small for gestational age (SGA). This study was conducted to assess the long-term efficacy and safety of GH treatment in children born SGA. One hundred and twenty prepubertal SGA children who did not achieve catch-up growth with height remained less than -2 standard deviations (SD) below gender-specific height were enrolled in this two-year, randomized, dose-comparative study followed by an extension study of up to 10 years. Daily subcutaneous injections of 0.23 mg/kg/week [low-dose (LD) group] or 0.46 mg/kg/week [high-dose (HD) group] somatropin were given for 104 weeks. Dosing in the extension study was≤0.46 mg/kg/week. The main outcome measures were change in height SD score (ΔHT-SDS), height velocity, insulin-like growth factor (IGF)-1, and IGF-1/IGF binding protein-3 (IGFBP-3) molar ratio. ΔHT-SDS at week 104 was 0.91±0.53 and 1.52±0.64 in the LD and HD groups (intergroup p<0.0001), respectively, and continued in an upward trend throughout the extension study, remaining above+2 for those who received treatment for a total of 7 years or more. At week 104, significant improvements were observed in height velocity, IGF-1 SDS, and IGF-1/IGFBP-3 molar ratio. Adult HT-SDS was -0.81±1.68 for boys and -0.82±1.05 for girls (p=0.9837). Glucose metabolism and thyroid function were within the normal reference range throughout treatment. Long-term recombinant human GH treatment was tolerable and effective at improving height in children born SGA.

Perception of Adherence to Daily Human Growth Hormone Treatments Among Pediatric and Adolescent Patients in Japan: A Cross-Sectional Survey of Physicians and Caregivers

BACKGROUND

Poor adherence to daily human growth hormone (hGH) treatment has been shown to be associated with poor clinical outcomes for growth hormone deficiency (GHD) patients. However, few studies have examined the perception of adherence to hGH treatment among both physicians and caregivers in Japan.

OBJECTIVE

The aim of this study is to examine the perception of adherence for daily hGH treatment among physicians and caregivers of pediatric and adolescent patients treated with GH in Japan. Moreover, we explore reasons for skipping treatment and the potential impact of a once-weekly treatment on adherence.

METHODS

A cross-sectional survey was conducted in Japan among physicians that prescribe daily hGH treatment and caregivers that have administered daily hGH treatment to children/adolescents for 3 months or longer. The Morisky Medication Adherence Scale (MMAS-8) was used to gauge perceived adherence for both physician and caregiver groups. Caregivers were also questioned regarding reasons for missing injections. Moreover, both groups were asked about the impact of a once-weekly treatment on adherence.

RESULTS

Responses were collected from 123 physicians and 112 caregivers. Physicians reported that 18.1% of patients have poor adherence based on the MMAS-8 instrument. In contrast, 32.1% of the caregivers reported poor adherence. "Simply forgetting", "Patient refused/resisted", and being "Busy with school activities, etc" were the most commonly selected reasons by caregivers for missing an injection. Physicians felt that a once-weekly injection could improve adherence for 64.5% of patients with poor adherence. Moreover, 56.9% of the caregivers that reported an experience of missed injections felt that a once-weekly injection would improve their adherence.

CONCLUSION

Approaches to improve adherence to hGH treatment in Japan are continuously needed. While further research is needed to understand factors most likely to improve adherence, availability of a once-weekly treatment is expected to help improve adherence.

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.

Monitoring Adherence Rate to Growth Hormone Therapy and Growth Outcomes in Taiwanese Children Using Easypod Connect: Observational Study

BACKGROUND

Adherence to growth hormone therapy is difficult to detect reliably. Devices such as easypod have been developed for electronic recording of injections. The easypod connect observational study (ECOS) was an open-label, observational, multinational, phase IV study conducted in 24 countries around the world. The final results from ECOS in the Taiwanese cohort are reported in this paper.

OBJECTIVE

This study aimed to evaluate the adherence and long-term outcomes of growth hormone therapy in pediatric subjects using the easypod electromechanical device.

METHODS

Subjects (aged 2-18 years or >18 years without fusion of growth plates) who received Saizen (recombinant human growth hormone, somatropin) via the easypod device were enrolled in this study. The primary objective was to assess the level of adherence in subjects receiving Saizen via easypod.

RESULTS

In Taiwan, a total of 35 and 13 children fulfilled the criteria of full analysis set and complete analysis set, respectively. The mean (SD) age of the complete analysis set was 12.08 (2.72) years. All subjects were growth hormone-naïve, with 38% (5/13) females. The mean adherence rates of 13 subjects were 87.6% at 3 months and 84.3% at 6 months, that of 8 subjects was 81.0% at 9 months, and that of 4 subjects was 91.6% at 1 year. After 1 year of treatment, subjects had a median (Q1:Q3) change in height SD score of 0.30 (0.06:0.48), median height velocity of 6.50 (4.33:8.24) cm/year, and median change in height velocity SD score of 1.81 (-0.04:3.52).

CONCLUSIONS

With the easypod device, patients with inadequate adherence and poor response to treatment can be identified. Adherence to growth hormone therapy administered via easypod was generally high in the first year of treatment but the adherence gradually decreased over time. Overall, growth outcomes after 1 year indicated a positive growth response to growth hormone treatment. Future efforts should be focused on personalized management of adherence by using the easypod system.

Genetic Screening for Growth Hormone Therapy in Children Small for Gestational Age: So Much to Consider, Still Much to Discover

Children born small for gestational age (SGA), and failing to catch-up growth in their early years, are a heterogeneous group, comprising both known and undefined congenital disorders. Care for these children must encompass specific approaches to ensure optimal growth. The use of recombinant human growth hormone (rhGH) is an established therapy, which improves adult height in a proportion of these children, but not with uniform magnitude and not in all of them. This situation is complicated as the underlying cause of growth failure is often diagnosed during or even after rhGH treatment discontinuation with unknown consequences on adult height and long-term safety. This review focuses on the current evidence supporting potential benefits from early genetic screening in short SGA children. The pivotal role that a Next Generation Sequencing panel might play in helping diagnosis and discriminating good responders to rhGH from poor responders is discussed. Information stemming from genetic screening might allow the tailoring of therapy, as well as improving specific follow-up and management of family expectations, especially for those children with increased long-term risks. Finally, the role of national registries in collecting data from the genetic screening and clinical follow-up is considered.

Fat distribution in short-stature children born small for gestational age

BACKGROUND

Children born small for gestational age (SGA) with catch-up growth are at high risk for developing obesity; however, the characteristics of body composition, especially fat distribution, before and after growth hormone (GH) treatment in SGA children without catch-up growth remains largely unknown.

METHODS

Anthropometric characteristics, body composition by dual-energy X-ray absorption, and fat distribution by computed tomography at the umbilical level were examined in 27 prepubertal short-stature children born SGA before and 1 year after GH treatment.

RESULTS

Before GH treatment, short-stature SGA children had lean phenotypes, and both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were significantly lower than the age- and sex-matched Japanese reference values. Growth hormone treatment significantly increased height standard deviation scores (SDS), without affecting body mass index SDS. Percentage fat mass decreased with GH treatment; however, fat mass was not altered. Both VAT and SAT were significantly lower than the reference values after GH treatment. The ratio of VAT over SAT significantly increased by GH treatment.

CONCLUSIONS

Both VAT and SAT were within or below the age- and sex-matched Japanese reference values in short-stature children born SGA before and after GH treatment, indicating that GH treatment may not have unfavorable effects on adiposity in short-stature children born SGA, although it may alter fat distribution.

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.