Monitoring treatment of central precocious puberty using basal luteinizing hormone levels and practical considerations for dosing with a 3-month leuprolide acetate formulation

Precocious Puberty and GnRH Analogs: Current Treatment Practices and Perspectives among US Pediatric Endocrinologists

INTRODUCTION

Gonadotropin releasing hormone analogs (GnRHas) are used for treatment of precocious puberty. Over the last decade, several new formulations have been approved.

METHODS

The Drugs and Therapeutics Subcommittee of the Pediatric Endocrine Society (PES) undertook a review to ascertain the current treatment options, prescribing behaviors, and practices of GnRHas among pediatric endocrinologists practicing within the USA. The survey consisted of four main subsections: (1) description of clinical practice; (2) self-assessment of knowledge base of pediatric and adult GnRHa formulations; (3) current practice for treating central precocious puberty (CPP); and (4) utilization of healthcare resources.

RESULTS

There were 223 survey respondents. Pediatric endocrine practitioners were most familiar with the pediatric one-monthly preparation, the 3-month preparation, and the histrelin implant (Supprelin®) (88%, 96%, and 91%, respectively), with lower familiarity for 24-week triptorelin intramuscular (Triptodur®) (65%) and 6-month subcutaneous leuprolide (Fensolvi®) (45%). Only 23% of the respondents reported being extremely familiar with the availability of adult formulations, and 25% reported being completely unaware of cost differences between pediatric and adult GnRHa preparations. The implant was the most preferred therapy (44%), but in practice, respondents reported a higher percentage of patients treated with the 3-month preparation. While family preference/ease of treatment (87%) was the key determinant for using a particular GnRHa preparation, insurance coverage also played a significant role in the decision (64%). Responses regarding assessment for efficacy of treatment were inconsistent, as were practices and criteria for obtaining an MRI.

CONCLUSIONS

The survey indicated there is more familiarity with older, shorter acting GnRHas, which are prescribed in greater numbers than newer, longer acting formulations. There is lack of consensus on the need for central nervous system (CNS) imaging in girls presenting with CPP between 6 and 8 years of age and use of laboratory testing to monitor response to treatment. Insurance requirements regarding CNS imaging and laboratory monitoring are highly variable. Despite having similar constituents and bioavailability, there are substantial cost differences between the pediatric and adult formulations and lack of evidence for safe use of these formulations in children. The survey-based analysis highlights the challenges faced by prescribers while reflecting on areas where further research is needed to provide evidence-based practice guidelines for pediatric endocrinologists.

Unstimulated Luteinizing Hormone for Assessment of Suppression during Treatment of Central Precocious Puberty with 6-Month Subcutaneous Leuprolide Acetate: Correlations with Clinical Response

INTRODUCTION

Phase 3 trial of 6-month subcutaneous leuprolide acetate (SC-LA) in children with central precocious puberty (CPP) demonstrated efficacy and safety. The aims of this secondary analysis were to evaluate unstimulated luteinizing hormone (LH) as efficacy measure, assess clinical suppression metrics, and present biochemical and clinical data for subgroups not achieving hormone suppression.

METHODS

Sixty-two children with treatment-naïve CPP received 2 doses of 45 mg SC-LA at 24-week intervals. Unstimulated and GnRH-stimulated LH, E2, and T concentrations were measured. Clinical measures included bone age (BA) and predicted adult height (PAH).

RESULTS

Eighty-four percentage and 86% of children achieved unstimulated LH <1 IU/L at weeks 24 and 48, respectively. Of 8 children not achieving unstimulated LH <1 IU/L at week 24 that completed the study, all showed a lack of pubertal stage progression and stable/decreased BA to chronological age ratio (BA/CA). Received operating characteristic (ROC) analyses suggested unstimulated LH is a good diagnostic predictor of GnRH-stimulated LH <4 IU/L at weeks 24 and 48 (AUC = 0.88). Across all children, mean BA/CA improved from 1.4 (screening) to 1.3 (week 48) and mean PAH increased by 3 cm. Of 7 girls not achieving stimulated LH <4 IU/L at week 24, all achieved E2 <10 pg/mL, showed a lack of pubertal stage progression, and had stable or decreased BA/CA by week 48. Additionally, 6/7 had increased PAH by week 48 and 4 had unstimulated LH <1 IU/L.

CONCLUSION

Unstimulated LH has value as an efficacy measure and concentrations <1 IU/L may be an adequate surrogate of treatment response in children with CPP. All children who completed the study had evidence of pubertal suppression.

Impact of 6-month triptorelin formulation on predicted adult height and basal gonadotropin levels in patients with central precocious puberty

BACKGROUND

Triptorelin, a long-acting gonadotropin-releasing hormone (GnRH) agonist, is available in 1-, 3-, and 6-month formulations to treat central precocious puberty (CPP). The triptorelin pamoate 22.5-mg 6-month formulation recently approved for CPP offers greater convenience to children by reducing the injection frequency. However, worldwide research on using the 6-month formulation to treat CPP is scarce. This study aimed to determine the impact of the 6-month formulation on predicted adult height (PAH), changes in gonadotropin levels, and related variables.

METHODS

We included 42 patients (33 girls and nine boys) with idiopathic CPP treated with a 6-month triptorelin (6-mo TP) formulation for over 12 months. Auxological parameters, including chronological age, bone age, height (cm and standard deviation score [SDS]), weight (kg and SDS), target height (TH), and Tanner stage, were evaluated at baseline, and after 6, 12, and 18 months of treatment. Hormonal parameters, including serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol for girls or testosterone for boys, were analyzed concurrently.

RESULTS

The mean age at treatment initiation was 8.6 ± 0.83 (8.3 ± 0.62 for girls, 9.6 ± 0.68 for boys). The peak LH level following intravenous GnRH stimulation at diagnosis was 15.47 ± 9.94 IU/L. No progression of the modified Tanner stage was observed during treatment. Compared to baseline, LH, FSH, estradiol, and testosterone were significantly reduced. In particular, the basal LH levels were well suppressed to less than l.0 IU/L, and the LH/FSH ratio was less than 0.66. The bone age/chronological age ratio remained stable with a decreasing trend (1.15 at the start of treatment, 1.13 at 12 months, 1.11 at 18 months). PAH SDS increased during treatment (0.77 ± 0.79 at baseline, 0.87 ± 0.84 at the start of treatment, 1.01 ± 0.93 at six months, and 0.91 ± 0.79 at 12 months). No adverse effects were observed during treatment.

CONCLUSION

The 6-mo TP suppressed the pituitary-gonadal axis stably and improved the PAH during treatment. Considering its convenience and effectiveness, a significant shift to long-acting formulations can be expected.

Efficacy of Triptorelin 3-Month Depot Compared to 1-Month Depot for the Treatment of Korean Girls with Central Precocious Puberty in Single Tertiary Center

BACKGROUND

Triptorelin depot is largely used to treat central precocious puberty (CPP) in children, and a 3-month depot has been introduced. However, data about the 3-month gonadotropin-releasing hormone use for treatment of CPP in Korean girls are not available. This study was conducted to compare the efficacy of a triptorelin 11.25 mg 3-month depot with that of a 3.75 mg 1-month depot in suppressing pubertal development for the treatment of CPP.

METHODS

A retrospective study, including 106 girls with CPP treated with triptorelin, was conducted. Fifty patients were treated with a triptorelin 3-month depot, and 56 were treated with a triptorelin 1-month depot. Serum luteinizing hormone (LH), follicle-stimulating hormone, and estradiol levels were analysed every 6 months after the visit. The height and bone age of each patient was evaluated at the beginning of treatment, after 6 months, and one year after therapy.

RESULTS

The baseline characteristics of the girls treated with a 3-month depot were similar to those of the girls treated with a 1-month depot. A suppressed levels of LH to the triptorelin injection (serum LH < 2.5 IU/L) at 6 months was seen in 90.0% and 98.2% of the girls treated with the 3-month and 1-month depots, respectively (P = 0.160). After 1 year of treatment, a suppressed levels of LH was seen in 93.5% and 100% of the girls treated with the 3-month and 1-month depots, respectively (P = 0.226). Height velocity showed no significant difference between the two groups. Degree of bone age advancement decreased from 1.22 ± 0.07 and 1.22 ± 0.08 years at baseline (P = 0.914) to 1.16 ± 0.07 and 1.17 ± 0.08 in the girls treated with the 3-month and 1-month depots after 1 year, respectively (P = 0.481).

CONCLUSION

This study showed that the efficacy of long-acting triptorelin 3-month was comparable to 1-month depot regarding hormonal suppression and inhibition of bone maturation. The triptorelin 11.25 mg 3-month depot is an effective treatment for girls with CPP.

Elevated Pre-injection Basal Luteinizing Hormone Concentrations are Common in Girls Treated for Central Precocious Puberty

OBJECTIVE

A consensus on how to monitor girls with central precocious puberty (CPP) during gonadotropin-releasing hormone agonist (GnRHa) treatment is lacking. Increased, unstimulated basal luteinizing hormone (LH) concentrations have been suggested to indicate lack of suppression. The aim was to evaluate pre-injection basal LH concentrations during GnRHa (leuprorelin 3.75 mg) treatment every four weeks in girls with CPP.

METHODS

Medical records were reviewed for girls with CPP treated at a single center from 2014-2019. Clinical characteristics and laboratory findings during treatment were systematically recorded.

RESULTS

A total of 587 GnRHa pre-injection basal LH concentrations were analyzed in 74 girls. Basal LH was pubertal (≥0.3 IU/L) in 53.5% of blood samples and 87.8% of all girls had a pubertal basal LH concentration at least once. A GnRH test (n=29) was repeated in 23 girls due to suspicion of clinical progression, elevated basal LH or recordable estradiol concentrations. None had a stimulated LH >3.1 IU/L. The predictability of treatment suppression (specificity) of basal LH concentrations was 12.0% when compared to repeated GnRH stimulation tests. Despite shortening the GnRHa injection interval to three weeks, basal LH concentrations remained pubertal in 85.7% girls. A significant reduction in height standard deviation score (p<0.001) and bone age advance (p<0.001) was observed during treatment.

CONCLUSION

Pre-injection basal LH remains at pubertal concentrations during treatment with leuprorelin 3.75 mg in girls with CPP. Clinical monitoring of pubertal progression is preferable to routine basal LH concentrations. Repeat GnRH stimulation testing should be regarded as the gold standard.

Use of Gonadotropin-Releasing Hormone Analogs in Children: Update by an International Consortium

This update, written by authors designated by multiple pediatric endocrinology societies (see List of Participating Societies) from around the globe, concisely addresses topics related to changes in GnRHa usage in children and adolescents over the last decade. Topics related to the use of GnRHa in precocious puberty include diagnostic criteria, globally available formulations, considerations of benefit of treatment, monitoring of therapy, adverse events, and long-term outcome data. Additional sections review use in transgender individuals and other pediatric endocrine related conditions. Although there have been many significant changes in GnRHa usage, there is a definite paucity of evidence-based publications to support them. Therefore, this paper is explicitly not intended to evaluate what is recommended in terms of the best use of GnRHa, based on evidence and expert opinion, but rather to describe how these drugs are used, irrespective of any qualitative evaluation. Thus, this paper should be considered a narrative review on GnRHa utilization in precocious puberty and other clinical situations. These changes are reviewed not only to point out deficiencies in the literature but also to stimulate future studies and publications in this area.

Elevated Random Luteinizing Hormone is an Unreliable Indicator for Pubertal Suppression in Girls Treated with Monthly Leuprolide for Idiopathic Central Precocious Puberty

Objective

Longitudinal data regarding random luteinizing hormone (LH) concentrations in patients with idiopathic central precocious puberty (ICPP) during treatment are limited. Therefore, we sought to evaluate random LH and estradiol concentrations during monthly leuprolide injection and their associations with pubertal progression and final adult height (FAH) in girls with ICPP.

Methods

Medical records of 27 girls with ICPP who had attained FAH were reviewed. Patients’ height, weight, Tanner stage, growth rate (GR), bone age, random LH measured by both immunoradiometric and immunochemiluminescent methods, follicular-stimulating hormone (FSH) and estradiol levels were monitored until FAH.

Results

Treatment was started at a mean (±standard deviation) age of 8.1±0.6 years with mean duration of 3.9±0.2 years. At six months of follow-up, random LH (p=0.048), FSH (p<0.001) and estradiol (p=0.023) concentrations were decreased compared with baseline. Thereafter, random LHs were well suppressed. GRs gradually decreased to prepubertal norm by month 12. Seventeen patients (63%) exhibited pubertal LH concentrations at least once during treatment visits. Furthermore, 43 of a total 116 (37%) LH measurements were found elevated. However, those patients with elevated random LH did not show signs of pubertal progression. After treatment, mean FAH was greater than predicted adult height (p<0.0001) and target height (p=0.03). At no time points of treatment did random LH, FSH and estradiol correlate with GRs or FAH.

Conclusion

Elevated random LH is commonly found in ICPP girls during monthly leuprolide treatment. However, these elevations were not associated with clinical progression of puberty or decreased FAH, suggesting that it is not a reliable method for CPP monitoring.

Predictors of bone maturation, growth rate and adult height in children with central precocious puberty treated with depot leuprolide acetate

BACKGROUND

Children with central precocious puberty (CPP) are treated with gonadotropin-releasing hormone agonists (GnRHa) to suppress puberty. Optimizing treatment outcomes continues to be studied. The relationships between growth, rate of bone maturation (bone age/chronological age [ΔBA/ΔCA]), luteinizing hormone (LH), predicted adult stature (PAS), as well as variables influencing these outcomes, were studied in children treated with depot leuprolide (LA Depot) Methods: Subjects (64 girls, seven boys) with CPP received LA Depot every 3 months for up to 42 months. Multivariate regression analyses were conducted to examine the predictors affecting ΔBA/ΔCA, PAS and growth rate.

RESULTS

Ninety percent of subjects (18 of 20) were suppressed (LH levels <4 IU/L) at 42 months. Over 42 months, the mean growth rate declined 2 cm/year, the mean BA/CA ratio decreased 0.21 and PAS increased 8.90 cm for girls (n=64). PAS improved to mid-parental height (MPH) in 46.2% of children by 30 months of treatment. Regression analysis showed that only the Body Mass Index Standardized Score (BMI SDS) was significantly associated (β+0.378 and +0.367, p≤0.05) with growth rate. For PAS, significant correlations were with MPH (β+0.808 and +0.791, p<0.001) and ΔBA/ΔCA (β+0.808 and +0.791, p<0.001). For ΔBA/ΔCA, a significant association was found only with BA at onset of treatment (β-0.098 and -0.103, p≤0.05). Peak-stimulated or basal LH showed no significant influence on growth rate, ΔBA/ΔCA or PAS.

CONCLUSIONS

Growth rate and bone maturation rate normalized on treatment with LA Depot. LH levels were not significantly correlated with growth rate, ΔBA/ΔCA or PAS, suggesting that suppression was adequate and variations in gonadotropin levels were below the threshold affecting outcomes.