Can some growth hormone (GH)-deficient children benefit from combined therapy with gonadotropin-releasing hormone analogs and GH? Results of a retrospective study

Efficacy and safety of a 4-year combination therapy of growth hormone and gonadotropin-releasing hormone analogue in pubertal girls with short predicted adult height

OBJECTIVES

To improve adult height in pubertal girls with a poor height prediction, treatment with growth hormone (GH) can be used in combination with a gonadotropin releasing hormone agonist (GnRHa), to delay closure of the growth plates. However, there are few studies to support this practice, and they show conflicting results. The objective of this trial is to assess the safety and efficacy of this combination treatment in early pubertal girls with a short predicted height, in comparison with matched controls.

DESIGN PATIENTS AND METHODS

We designed an open-label, multicenter, interventional case-control study. Early pubertal girls with predicted adult height (PAH) below -2.5 SDS, were recruited in tertiary care centers in Belgium. They were treated for four years with GH and GnRHa. The girls were followed until adult height (AH) was reached. AH vs PAH, AH vs Height at start, and AH vs Target Height (TH) were evaluated, as well as safety parameters. Control data were assembled from historical patient files or from patients who preferred not to participate in the study.

RESULTS

Sixteen girls with mean age ( ± SD) at start of 11.0 years (± 1.3) completed the study protocol and follow-up. Their mean height ( ± SD) increased from 131.3 ± 4.1 cm (-2.3 ± 0.7 SDS) at start of treatment to 159.8 ± 4.7 cm (-1.1 ± 0.7 SDS) at AH. In matched controls, height increased from 132.3 ± 4.2 cm (-2.4 ± 0.5 SDS) to 153.2 ± 3.4 cm (-2.1 ± 0.6 SDS) (p<0.001). AH surpassed initial PAH by 12.0 ± 2.6 cm in treated girls; and by 4.2 ± 3.6 cm in the controls (p<0.001). Most treated girls reached normal adult height (>-2SD) (87.5%) and 68.7% reached or superseded the target height (TH), which was the case in only a minority of the controls (37.5% and 6.2%, respectively) (p= 0.003 and 0.001). A serious adverse event possibly related to the treatment, was a fracture of the metatarsals.

CONCLUSION

A four-year GH/GnRHa treatment in early pubertal girls with a poor PAH seems safe and results in a clinically relevant and statistically significant increase in AH compared with matched historical controls.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT00840944.

Development and validation of a nomogram to predict poor short-term response to recombinant human growth hormone treatment in children with growth disorders

PURPOSE

The purpose of this study was to develop and validate a clinical predictive model for predicting the likelihood of a poor therapeutic response during the first year of recombinant human growth hormone (rhGH) treatment in children with growth disorders.

METHODS

A total of 627 pediatric patients with growth disorders (GHD, ISS, TS, SGA) from The LG Growth Study cohort were evaluated. Restricted cubic splines (RCS) were utilized to investigate the association between predictors and the risk of poor rhGH response. Variables were selected using LASSO regression, and multivariate logistics regression models were established. Receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC) were used to assess the predictive model's accuracy and clinical value. The predictive accuracy of the model was validated on the testing set.

RESULTS

Two predictive models containing 8 baseline predictors (diagnosis, age, height SDS, bone age minus chronological age, rhGH dosage, distance from mid-parental height in SDS, weight SDS, IGF-1 SDS) and 1 post-treatment predictor (height SDS gain at 6 months) were constructed by multivariate logistic regression analyses. The nomogram was built based on the multivariate predictive model and showed good discrimination and model fit effects in both the training set and the testing set. DCA and CIC analyses presented good clinical usability.

CONCLUSION

The clinical predictive model for predicting the probability of poor short-term response of rhGH treatment in pediatric patients with growth disorders is useful and can assist physicians in making clinical decisions.

The Effect of Gonadotropin-Releasing Hormone Analogue on Final Adult Height in Children with Idiopathic Short Stature

OBJECTIVE

To assess final adult height (FAH) in children with short stature treated with gonadotropin-releasing hormone analogue (GnRHa).

METHODS

All patients with idiopathic short stature (ISS) with normally timed puberty and a Tanner stage between 2 and 3, who achieved their FAH between 2005 and 2015, were included in this clinical historical cohort study. Height gain, FAH, and mid-parental height of 28 children with ISS who received GnRHa treatment for 1.8 ± 1.0 years to delay their puberty were compared to 31 untreated children.

RESULTS

The FAHs of the treated and the untreated girls were 151.3 ± 5.1 and 146.8 ± 3.8 cm (p = 0.01), respectively. The FAHs of the treated and the untreated boys were 156.4 ± 4.7 and 152.3 ± 5.7 cm (p = 0.111), respectively. The height gain in the treated and the untreated girls was 1.6 ± 7.8 and -3.6 ± 5.7 cm (p = 0.036), respectively. Height gain in the treated and the untreated boys was -5.1 ± 13.6 and -11.5 ± 8.4 cm (p = 0.171), respectively.

CONCLUSION

GnRHa therapy has a modest effect in improving FAH in adolescent females with ISS but not in boys.

Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height

Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin^®) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (p<0.0001). The mean adult height was significantly greater in the combination treatment group (164.3 cm) than in the untreated group (156.9 cm) (p<0.0001). The percentage of subjects with an adult height of 160 cm or taller was 90.5% (19/21) in the combination treatment group, and it was 13.8% (4/29) in the untreated group (p<0.0001). Since growth of the penis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone.

Height gain with combined growth hormone and gonadotropin-releasing hormone analog therapy in two pubertal siblings with a growth hormone-releasing hormone receptor mutation

CONTEXT

Patients with GHRH receptor (GHRH-R) mutations present with familial isolated GH deficiency, which untreated leads to a severely compromised adult height. Few data are available about the efficacy of treatment with GH in combination with a GnRH analog (GnRHa) in adolescence.

OBJECTIVE

The objective of the study was to describe the evolution of growth and skeletal age of a brother and sister of Moroccan descent with a homozygous GHRH-R mutation who presented at an advanced age (16 and 14.9 yr, respectively) and pubertal stage (Tanner stage G4 and B3, respectively) with a height of -5.1 sd score and -7.3 sd score on treatment with a combination of GH and GnRHa for 2.5 and 3 yr followed by GH alone.

METHODS

GH was given in a dosage of 0.7 mg/m2.d (25 microg/kg.d) sc and triptorelin in a dosage of 3.75 mg per 4 wk im. Height and pubertal stage were measured three-monthly, bone age yearly.

RESULTS

Combined GH and GnRHa treatment resulted in a height gain of 24 and 28.2 cm, respectively, compared with the initial predicted adult height by the method of Bayley and Pinneau. Adult height was within the population range and well within the target range.

CONCLUSIONS

Our patients demonstrate that, in case of isolated GH deficiency caused by a GHRH-R mutation, combined treatment of GH and GnRHa can be very effective in increasing final height, even at an advanced bone age and pubertal stage.

Management of short stature with GnRH agonist and co-treatment with growth hormone: a controversial issue

Adolescent growth is the focus of several interventions aimed at increasing the amplitude of the adolescent spurt. Favorable results with GnRH agonists in precocious puberty have encouraged attempts to increase the duration of the adolescent growth spurt by delaying normal puberty in short individuals using GnRH agonists with or without growth hormone. These approaches remain highly controversial, have not been validated and approved for use by regulatory authorities and were the topic of a session at the 6th International Conference on the Onset of Puberty. Here we review the available information on the efficacy and safety of this approach. GnRH agonists, when used outside the context of precocious puberty, induce a modest gain when used for extended periods of time. Several trials have now shown that growth hormone alone can modestly increase adult height in short adolescents with idiopathic short stature or in those born small for gestational age. The association of growth hormone and GnRH agonists still lacks a definite demonstration of its additional efficacy and available results do not allow firm conclusions. In conclusion, watchful waiting or sex steroids in delayed puberty are generally the best options in short children presenting around puberty. However, long-term and adequately powered clinical trials, focusing on efficacy, safety and clinical significance are needed to fully evaluate the combination of growth hormone and GnRH agonists in short adolescents. In the meanwhile, these approaches should be considered as experimental.

Phenotypic analysis and growth response to different growth hormone treatment schedules in two siblings with an inactivating mutation in the growth hormone-releasing hormone receptor gene

Mutations in the GHRH receptor (GHRHR) gene (GHRHR) are emerging as a common cause of familial isolated growth hormone deficiency (IGHD) type IB. The use of gonadotropin-releasing hormone (GnRH) analogues has been advocated as a tool to delay puberty in patients with isolated GH deficiency (IGHD), allowing longer time for the beneficial effect of exogenous human GH (hGH) treatment on growth. We describe two male siblings with IGHD due to a homozygous missense GHRHR mutation who, because they were started on hGH therapy at different ages, presented with different height SDS at the onset of puberty and therefore had different predicted target heights. The shorter brother was treated with GnRH analogue plus hGH for 3 years, whereas the other brother received only hGH. Despite different predicted heights at the onset of puberty, they attained similar final heights. We conclude that in patients with IGHD, GnRH analogue treatment should be considered to delay puberty and obtain a maximal growth response if hGH treatment is started in late childhood and the predicted height at puberty onset is below the genetic target.