Long-Term Continuous Suppression With Once-Yearly Histrelin Subcutaneous Implants for the Treatment of Central Precocious Puberty: A Final Report of a Phase 3 Multicenter Trial

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.

Therapeutic effects of melatonin in female mice with central precocious puberty by regulating the hypothalamic Kiss-1/Kiss1R system

In recent years, central precocious puberty (CPP) in children is becoming more common, which seriously affects their physical and psychological health and requires finding a safe and effective treatment method. The aim of this study was to investigate the therapeutic effect of melatonin on CPP. A CPP model was established by subcutaneous injection of 300 micrograms of danazol into 5-day-old female mice, followed by treatment with melatonin and leuprolide. The vaginal opening was checked daily. Mice were weighed, gonads were weighed, gonadal index was calculated, and gonadal development was observed by hematoxylin and eosin (HE) staining. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels were measured by ELISA. By using RT-PCR and Western blotting, the mRNA and protein expression of the hypothalamus Kiss-1, Kiss-1 receptor (Kiss1R), gonadotropin-releasing hormone (GnRH), and pituitary GnRH receptor (GnRHR) were identified. The results showed that melatonin delayed vaginal opening time and reduced body weight, gonadal weight and indices in female CPP mice. Melatonin treatment prevents uterine wall thickening and ovarian luteinization in female CPP mice. Melatonin treatment reduces serum concentrations of FSH, LH, and E2 in female CPP mice. Melatonin suppressed the expressions of Kiss-1, Kiss1R and GnRH in the hypothalamus, and the expression of GnRHR in the pituitary of the female CPP mice. Our results suggest that melatonin can inhibit the hypothalamic-pituitary-gonadal (HPG) axis by down-regulating the Kiss-1/Kiss1R system, thereby treating CPP in female mice.

Central precocious puberty: a review of diagnosis, treatment, and outcomes

Central precocious puberty (CPP) refers to early activation of the hypothalamic-pituitary-gonadal (HPG) axis and is manifested by breast development in girls or testicular enlargement in boys before the normal physiological age ranges. CPP can be precipitated by intracranial pathology, exposure to high levels of sex steroids, or environmental risk factors, but most cases are idiopathic. Monogenic causes have also been identified. In this Review, we summarise pathophysiology, risk factors, diagnosis, and management of CPP. Concern for CPP should prompt referral to paediatric endocrinology where diagnosis is confirmed by clinical, biochemical, radiological, and genetic testing. CPP is treated with a gonadotropin-releasing hormone analogue, the primary aims of which are to increase adult height and postpone development of secondary sexual characteristics to an age that is more commensurate with peers. Although long-term outcomes of treatment with gonadotropin-releasing hormone analogues are reassuring, additional research on the psychological effect of CPP is needed.

Solid implantable devices for sustained drug delivery

Implantable drug delivery systems (IDDS) are an attractive alternative to conventional drug administration routes. Oral and injectable drug administration are the most common routes for drug delivery providing peaks of drug concentrations in blood after administration followed by concentration decay after a few hours. Therefore, constant drug administration is required to keep drug levels within the therapeutic window of the drug. Moreover, oral drug delivery presents alternative challenges due to drug degradation within the gastrointestinal tract or first pass metabolism. IDDS can be used to provide sustained drug delivery for prolonged periods of time. The use of this type of systems is especially interesting for the treatment of chronic conditions where patient adherence to conventional treatments can be challenging. These systems are normally used for systemic drug delivery. However, IDDS can be used for localised administration to maximise the amount of drug delivered within the active site while reducing systemic exposure. This review will cover current applications of IDDS focusing on the materials used to prepare this type of systems and the main therapeutic areas of application.

Approach to the Patient: Central Precocious Puberty

Central precocious puberty (CPP) classically refers to premature activation of the hypothalamic-pituitary-gonadal axis with onset of sexual development before the age of 8 years in girls and 9 years in boys. A decrease in the age of thelarche has been reported over the past several decades; however, the tempo of pubertal progression can be slower and adult height may not be adversely affected in many of the girls who experience thelarche at 6-8 years. Outside of this secular trend in the development itself, the past several decades have also brought about advances in diagnosis and management. This includes the widespread use of an ultrasensitive luteinizing hormone assay, decreasing the need for stimulation testing and a better understanding of the genetics that govern the onset of puberty. Additionally, management of CPP using gonadotropin-releasing hormone analogs (GnRHas) has changed with the advent of new longer-acting formulations. Emerging long-term outcomes of GnRHa administration with regards to obesity, cardiovascular risk factors and fertility are reassuring. Despite these advancements, clinical care in CPP is hampered by the lack of well-designed controlled studies, and management decisions are frequently not supported by clear practice guidelines. Data in boys with CPP are limited and this article focuses on the diagnosis and management of CPP in girls, particularly, in those who present with thelarche at the age of 6-8 years.

Long-term experience with the use of a single histrelin implant beyond one year in patients with central precocious puberty

OBJECTIVES

The histrelin implant has been used to treat central precocious puberty (CPP) for more than 15 years. Although approved for annual use, limited published reports suggest that a single implant is efficacious well beyond a year. Our objective was to report our long-term experience using a single histrelin implant for more than 12 months in children with CPP.

METHODS

We performed a retrospective study of 170 children with central precocious puberty treated with a single histrelin implant for more than 1 year.

RESULTS

Implants were left in situ for an average of 24 months. Pubertal development regressed or remained stable in the vast majority of patients and biochemical suppression was maintained. No correlation between time since an implant was placed and complications such as implant breakage or a second incision was seen.

CONCLUSIONS

A single histrelin implant provides excellent pubertal suppression well beyond a year. Extended use of a single histrelin implant should be considered standard of care in children with CPP.

Effect of CPP-related genes on GnRH secretion and Notch signaling pathway during puberty

Puberty is a complex biological process of sexual development, influenced by genetic, metabolic-nutritional, environmental and socioeconomic factors, characterized by the development of secondary sexual characteristics, maturation of the gonads, leading to the acquisition of reproductive capacity. The onset of central precocious puberty (CPP) is mainly associated with the early activation of the hypothalamic-pituitary-gonadal (HPG) axis and increased secretion of gonadotropin-releasing hormone (GnRH), leading to increased pituitary secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and activation of gonadal function. Due to the expense and invasiveness of current diagnostic testing and drug therapies for CPP, it would be helpful to find serum and genetic markers to facilitate diagnosis. In this paper, we summarized the related factors that may affect the expression of GnRH1 gene and the secretion and action pathway of GnRH and related sex hormones, and found several potential targets, such as MKRN3, DLK1 and KISS1. Although, the specific mechanism still needs to be further studied, we would be encouraged if the insights from this review could provide new insights for future research and clinical diagnosis and treatment of CPP.

A single blood sample for stimulated LH assayed by ICMA is useful for monitoring the treatment efficacy of triptorelin depot in girls

BACKGROUND

There is still no consensus on the optimal monitoring method to evaluate the hypothalamic-pituitary-gonadal axis (HPGA) inhibition.

METHODS

There were 124 girls treated with triptorelin depot due to puberty disorders, including 77 central precocious puberty and 47 early puberty. After treatment, triptorelin stimulation tests were performed, and blood samples were collected at 0, 20, 40 and 60 min. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by immunochemiluminometric assay (ICMA).

RESULTS

Peak LH (PLH), peak FSH and estradiol in 124 girls were significantly decreased after treatment, while 2 cases had inadequate treatment efficacy. Areas under the receiver operating characteristic curves (AUC) of PLH and peak FSH after stimulation for the diagnosis of HPGA suppression were 0.984 and 0.121. When the cut-off value of PLH was ≤ 2.25 IU/L, the sensitivity was 96.7% and specificity was 100.0%. There was no difference in AUC between PLH and a single LH at 20, 40, or 60 min (p > 0.05). When LH were ≤ 2.34 IU/L, ≤ 2.21 IU/L and ≤ 2.00 IU/L at 20, 40 and 60 min, respectively, the sensitivity were 99.1%, 96.7% and 98.4%, and the specificity were all 100.0%. The correlation coefficients between PLH and LH at 20, 40 or 60 min were 0.947, 0.975 and 0.961.

CONCLUSION

A single blood sample for stimulated LH at 20 min, 40 min, or 60 min assayed by ICMA during triptorelin stimulation test is useful for monitoring the treatment efficacy of triptorelin depot in girls with puberty disorders.

Gonadotropin Suppression for 7 Years After a Single Histrelin Implant for Precocious Puberty

Gonadotropin-releasing hormone analogues (GnRHas) are an effective treatment to address the compromise in height potential seen in patients with central precocious puberty. There is no evidence in the literature of a single GnRHa used for longer than 2 years before being removed or replaced. We describe a patient who was on continuous gonadotropin suppression for 7 years and despite this, achieved a height potential within 1 SD of mid-parental height. A boy aged 10 years 3 months presented to the endocrine clinic with signs of precocious puberty and advanced bone age. Initial laboratory values were a random luteinizing hormone (LH) level of 9.4 mIU/mL, follicle-stimulating hormone (FSH) 16.3 mIU/mL, dehydroepiandrosterone sulfate 127 mcg/dL, and testosterone 628 ng/dL. The patient was initially started on Lupron injections before transitioning to a histrelin implant. Follow-up laboratory results 5 months post-suppression showed pre-pubertal random LH 0.2 mIU/mL, FSH 0.1 mIU/mL, and testosterone 5 ng/dL. The patient was lost to follow-up and returned 5 years later presenting with gynecomastia and delayed bone age. He had continuous gonadotropin suppression with random LH 0.10 mIU/mL, FSH 0.16 mIU/mL, and testosterone 8 ng/dL. The histrelin implant was removed, and 4 months later, his random pubertal hormone levels were LH 5.6 mIU/mL, FSH 4.3 mIU/mL, and testosterone 506 ng/dL. The patient’s mid-parental height was 175.3 cm and his near final height was 170.6 cm, which is within 1 SD of his genetic potential. Further studies are needed to explore continuous gonadotropin hormone suppression with a single histrelin implant beyond 2 years.

Gonadotropin-releasing hormone analog therapies for children with central precocious puberty in the United States

Gonadotropin-releasing hormone agonists (GnRHa's) are the standard treatment for children with central precocious puberty (CPP). We aim to present data on available GnRHa options with an easy-to-review table and discuss factors that influence treatment selection. Five GnRHa's are currently FDA-approved and prescribed in the US and published data suggest similar safety and efficacy profiles over the first year of treatment. One- and 3-month intramuscular (IM) leuprolide acetate (LA) have long-term safety and efficacy data and allow for flexible dosing. Six-month IM triptorelin pamoate offers a longer duration of treatment, but without long-term efficacy and outcome data. Six-month subcutaneous (SQ) LA combines a SQ route of injection and long duration of action but lacks long-term efficacy and outcome data. The 12-month SQ histrelin acetate implant avoids injections and offers the longest duration of action, but requires a minor surgical procedure with local or general anesthesia. Factors in treatment selection include route of administration, needle size, injection volume, duration of action, and cost. The current GnRHa landscape provides options with varying benefits and risks, allowing physicians and caregivers to select the most appropriate therapy based on the specific needs and concerns of the child and the caregiver. Agents have different advantages and disadvantages for use, with no one agent displaying superiority.

Clinical characteristics and treatment patterns with histrelin acetate subcutaneous implants vs. leuprolide injections in children with precocious puberty: a real-world study using a US claims database

OBJECTIVES

Gonadotropin-releasing hormone analogs are the treatment of choice for central precocious puberty (CPP). This study characterizes patients treated with histrelin implant or leuprolide injection.

METHODS

A US claims database was used to identify patients aged ≤20 years with ≥1 histrelin or leuprolide claim (index treatment) between April 2010 and November 2017 and continuous enrollment ≥3 months before and ≥12 months after the index treatment date.

RESULTS

Overall, 4,217 patients (histrelin, n=1,001; leuprolide, n=3,216) were identified. The percentage of patients with CPP diagnosis was greater in the histrelin (96.5%) vs. leuprolide (68.8%; p<0.0001) cohort. In patients with CPP (histrelin, n=966; leuprolide, n=2,214), mean age at treatment initiation was similar for histrelin (9.0 ± 2.0 years) and leuprolide (9.1 ± 2.3 years), with >50% of patients aged 6-9 years. Mean treatment duration was significantly longer for histrelin (26.7 ± 14.8 months) vs. leuprolide (14.1 ± 12.1 months; p<0.0001), and was longer in younger patient groups. More patients switched from leuprolide to histrelin (12.3%) than vice versa (3.6%; p<0.0001). Median annual total treatment costs were slightly lower for the histrelin cohort ($23,071 [interquartile range, $16,833-$31,050]) than the leuprolide cohort ($27,021 [interquartile range, $18,314-$34,995]; p<0.0001).

CONCLUSIONS

Patients with CPP treated with histrelin had a longer duration of treatment, lower rates of index treatment discontinuation, and lower annual treatment costs vs. those treated with leuprolide.

Growth, growth potential, and influences on adult height in the transgender and gender-diverse population

The sexually dimorphic trait of height is one aspect of the experience of transgender and gender‐diverse (TGD) individuals that may influence their gender dysphoria and satisfaction with their transition. In this article, we have reviewed the current knowledge of the factors that contribute to one's final adult height and how it might be affected in TGD youth who have not experienced their gonadal puberty in the setting of receiving gonadotropin‐releasing hormone analog (GnRHa) and gender‐affirming hormonal treatment. Additional research is needed to characterize the influence of growth and final adult height on the lived experience of TGD youth and adults and how to best assess their growth, predict their final adult height, and how medical transition can be potentially modified to help them meet their goals.

Histrelin Implants for Suppression of Puberty in Youth with Gender Dysphoria: A Comparison of 50 mcg/Day (Vantas) and 65 mcg/Day (SupprelinLA)

Purpose: Development of incongruent secondary sex characteristics in transgender youth can intensify or trigger the onset of gender dysphoria. Guidelines from professional organizations recommend gonadotropin-releasing hormone agonists, including histrelin implants (Vantas and SupprelinLA) to suppress endogenous puberty. Although Vantas does not have a pediatric indication, it is anecdotally being used in pediatric gender centers throughout the United States because of its substantially lower cost. This retrospective study aimed to determine if both implants were effective in suppressing the hypothalamic-pituitary-gonadal axis in early-to-mid pubertal youth with gender dysphoria. Methods: Youth with gender dysphoria receiving care at the Center for Transyouth Health and Development at Children's Hospital Los Angeles (CHLA) or participants from an ongoing observational trial with a histrelin implant placed for pubertal suppression at Tanner stage 2 or 3 were included. Sex steroid (testosterone or estradiol) and gonadotropin measurements at baseline (T0) and then 2 to 12 months following implant placement (T1) were abstracted from medical records. Results: Of the 66 eligible participants, 52% were designated female at birth. Most participants were white (60.6%). Twenty participants (30.3%) had a Vantas implant and 46 (69.7%) had a SupprelinLA implant. Mean age of insertion was 11.3 years. Gonadotropin and sex steroid levels were significantly decreased at T1 (2-12 months after insertion of implant), with no differences between implants. Conclusion: These results indicate that both implants are effective in suppressing puberty in early-to-mid pubertal youth with gender dysphoria. These data may inform decisions about insurance coverage of Supprelin and/or Vantas for youth with gender dysphoria.

Delayed and Precocious Puberty: Genetic Underpinnings and Treatments

Delayed puberty may signify a common variation of normal development, or indicate the presence of a pathologic process. Constitutional delay of growth and puberty is a strongly familial type of developmental pattern and accounts for the vast majority of children who are "late bloomers." Individuals with sex chromosomal abnormalities frequently have hypergonadotropic hypogonadism. There are currently 4 known monogenic causes of central precocious puberty. The primary treatment goal in children with hypogonadism is to mimic normal pubertal progression, while the primary aims for the management of precocious puberty are preservation of height potential and prevention of further pubertal development.

A non-surgical approach to 46,XY differences in sex development through hormonal suppression at puberty: a single-center case series study

PURPOSE

We aim to report outcomes and safety with hormonal suppression to facilitate gonadal preservation in a select group of patients with 46,XY differences in sex development (DSD) who are raised and identify as female yet have diagnoses with potential for androgenization at puberty.

METHODS

We performed a retrospective review of the past 10 years of DSD patients treated by a multidisciplinary program. Inclusion criteria were 46,XY DSD, female sex of rearing, risk of androgenization at puberty, and plan for hormonal suppression at puberty. Patients on hormonal suppression had at least 6 months of follow-up from initiation. We excluded those with complete gonadal dysgenesis or complete androgen insensitivity.

RESULTS

Four patients met inclusion criteria. Initial evaluation by DSD team was at a mean age of 6.6 years (3 weeks-16 years). All patients were evaluated in a coordinated multidisciplinary clinic. The diagnoses are listed in Table 1. Mean follow-up was 5.7 years (1.2-10.9 years). One patient presented as an infant, and is being monitored until Tanner stage 2 and/or serum hormonal evidence to initiate hormonal suppression. Three patients have been receiving hormonal suppression for 1.4 years (1.1-1.9 years) without side effects or complication. Three patients were initiated with estrogen replacement to promote desired breast development. At last follow-up, all patients had retained their gonads, all have female gender identity with no reported gender dysphoria, and no progression of androgenization.

CONCLUSIONS

In our initial experience, gonadal preservation with hormonal suppression is a tool in multidisciplinary management of select DSD patients with female gender identity with conditions associated with androgenization at puberty. Patients' growth, bone health, and overall psychosocial well-being will need to be monitored closely.

Study on the Mechanism of Sarsasapogenin in Treating Precocious Puberty by Regulating the HPG Axis

The present study aims to investigate the effects and mechanisms of sarsasapogenin resistance to precocious puberty. Female Sprague Dawley rats were divided into a normal (N) group, model (M) group, leuprolide (L) group, and sarsasapogenin (Sar) group. Rats at 5 days of age were given a single subcutaneous injection of 300 micrograms of danazol to establish the precocious puberty model. After 10 days of modeling, drug intervention was started. The development of the uterus and ovary was observed by hematoxylin and eosin (HE) staining. The levels of the serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol (E2) were determined by radioimmunoassay. Also, the expressions of the hypothalamic gonadotropin releasing hormone (GnRH), Kiss-1, G protein-coupled receptor 54 (GPR54), and pituitary gonadotropin releasing hormone receptor (GnRH-R) were detected by RT-PCR. The results showed that compared with the model group, sarsasapogenin could significantly delay the opening time of vaginal, decreased uterine and ovarian coefficients, and reduced uterine wall thickness. Moreover, it can significantly downregulate the levels of serum hormones and reduce the expression of GnRH, GnRH-R, and kiss-1. In summary, our results indicate that sarsasapogenin can regulate the HPG axis through the kiss-1/GPR54 system for therapeutic precocious puberty.

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.

Histrelin Implantation and Growth Outcomes in Children With Congenital Adrenal Hyperplasia: An Institutional Experience

Background

Children with congenital adrenal hyperplasia (CAH) because of 21 hydroxylase deficiency (21OHD) are at risk for early or precocious puberty and a short adult height compared to population means and midparental height. The effect of histrelin in suppressing puberty and improving growth in these children has not been reported.

Methods

Retrospective cohort analysis of all patients (age ≤ 20) at our institution who underwent histrelin implantation between 2008 and 2017. Treated patients with CAH (classic and nonclassic forms of 21OHD) were identified and their growth data analyzed.

Results

Fifteen children with CAH were treated with histrelin for a median of 3 years (range 2–5; age at first implantation 7.7 ± 1.5 years). Bone age (BA) to chronologic age (CA) decreased from 1.57 ± 0.4 to 1.25 ± 0.25 (P < .01), while predicted adult height (PAH) increased by 7.1 ± 6.6 cm (P < .01). A subgroup of 10 children reached adult height. Similar changes in BA/CA and PAH were observed with therapy (P = .02). Adult height z improved compared to pretreatment PAH z (–1.42 ± 0.9 vs. –1.96 ± 1.1 respectively, P < .01), but remained lower than midparental height z (P = .01).

Conclusion

In this retrospective cohort study of children with CAH due to 21OHD and early or precocious puberty, histrelin implantation resulted in a decrease in BA progression compared to CA and an improvement in PAH. In the subgroup who completed growth, adult height remained significantly lower than midparental. These results need to be confirmed with prospective controlled studies.

Update on Precocious Puberty in Girls

Precocious puberty (PP) in girls refers to secondary sexual development occurring earlier than the lower end of normal for the onset of puberty. It might be the presenting feature of a serious underlying condition or signify a common variation of normal for which no treatment is necessary. Depending on the source and type of sex steroids involved, clinical findings may indicate exposure to estrogens, androgens, or both. Likewise, the onset of the PP might be gradual or abrupt and the rate of progression is variable. Recent years have witnessed exciting advancements in the understanding of the molecular genetic basis for some forms of PP in girls as well as in the development of additional treatment options. In this review an update on the most commonly encountered causes of PP in girls including their clinical presentation, pathophysiology, diagnosis, and management are provided. Recommendations regarding when to refer, and areas in particular need of additional research are also delineated.

Histrelin implantation in the pediatric population: A 10-year institutional experience

PURPOSE

To perform the largest review of the safety and clinical management practices of histrelin implantation in children.

METHODS

A retrospective cohort study was performed including all patients (age ≤ 20) that underwent histrelin implant insertion, replacement, or removal by a single surgeon at a large pediatric tertiary care center (2008-2017). Data analyzed included patient demographics, procedure details, and complications.

RESULTS

A total of 377 patients, with a mean age of 9.3 ± 2.4 years, underwent 866 unique procedures (352 insertions, 329 replacements, and 185 removals) for a diagnosis of either central precocious puberty (343 patients, 821 cases) or gender identity disorder (34 patients, 45 cases). There were 271 (72%) female patients, 72 (19%) male patients, and 34 (9%) children in gender transition. Procedures were performed in three settings: 415 (47.9%) in the outpatient clinic, 401 (46.3%) in a sedation unit, and 50 (5.8%) in the operating room. The preferred setting shifted over time to more clinic-based procedures (9.4% vs. 62.9% in the first five vs. second five years, respectively). Complications were rare (1% of cases).

CONCLUSION

Histrelin implantation in the pediatric population is safe, with minimal morbidity. Implantation and removal in the clinic setting are appropriate for the majority of patients.

LEVEL OF EVIDENCE

Treatment study; Level IV.

Central precocious puberty, functional and tumor-related

Precocious puberty is defined as the appearance of secondary sex characteristics before 8 years of age in girls and before 9 years of age in boys. Central precocious puberty (CPP) is diagnosed when activation of the hypothalamic-pituitary axis is identified. It is a rare disease with a clear female predominance. A background of international adoption increases its risk, with other environmental factors such as endocrine disruptors also being associated with CPP. The causes of CPP are heterogeneous, with alterations of the CNS being of special interest. Physical injuries of the CNS are more frequent in boys, while idiopathic etiology is more prevalent among girls. However, in the last decade the number of idiopathic cases has diminished thanks to the discovery of mutations in different genes, including KISS1, KISS1R, MKRN3, and DLK1 that cause CPP. For the diagnosis of CPP, hormone studies are needed in addition to the clinical data regarding signs of pubertal onset. For this purpose, the GnRH test continues to be the gold standard. Imaging analyses, such as bone age and brain MRI, are also very useful. Furthermore, genetic testing must be incorporated in the diagnosis of CPP, especially in familial cases. Early puberty has been related to various consequences in the medium and long term such as behavioral problems, breast cancer, obesity, and metabolic comorbidities. However, there are few studies that have exclusively analyzed patients with CPP. GnRH analogs are the most frequent treatment election with the main objective being to improve adult height. Currently, there are new formulations that are being investigated.

Advanced implantable drug delivery technologies: transforming the clinical landscape of therapeutics for chronic diseases

Chronic diseases account for the majority of all deaths worldwide, and their prevalence is expected to escalate in the next 10 years. Because chronic disorders require long-term therapy, the healthcare system must address the needs of an increasing number of patients. The use of new drug administration routes, specifically implantable drug delivery devices, has the potential to reduce treatment-monitoring clinical visits and follow-ups with healthcare providers. Also, implantable drug delivery devices can be designed to maintain drug concentrations in the therapeutic window to achieve controlled, continuous release of therapeutics over extended periods, eliminating the risk of patient non-compliance to oral treatment. A higher local drug concentration can be achieved if the device is implanted in the affected tissue, reducing systemic adverse side effects and decreasing the challenges and discomfort of parenteral treatment. Although implantable drug delivery devices have existed for some time, interest in their therapeutic potential is growing, with a global market expected to reach over $12 billion USD by 2018. This review discusses implantable drug delivery technologies in an advanced stage of development or in clinical use and focuses on the state-of-the-art of reservoir-based implants including pumps, electromechanical systems, and polymers, sites of implantation and side effects, and deployment in developing countries.

Treatment of Central Precocious Puberty

Long-acting analogs of GnRH (GnRHas) have been the gold-standard treatment of central precocious puberty (CPP) worldwide and have an enviable track record of safety and efficacy. Recent years have witnessed much growth in the availability of longer-acting and sustained-release forms of GnRHas. Although all available agents appear promising, limited long-term follow-up and/or comparative data are available. In this review, important issues pertaining to the treatment of children with CPP are discussed. In addition to an assessment of the newer extended-release GnRHa formulations, a delineation of factors essential in determining which children should be treated is offered. Outstanding uncertainties in clinical management are highlighted and areas in need of future research identified. Literature searches for this review were performed in PubMed and OVID, with a focus on English-language publications using the terms "central precocious puberty" and "treatment."

Update on central precocious puberty: from etiologies to outcomes

INTRODUCTION

Precocious puberty (PP) is one of the most common reasons for referral to pediatric endocrinologists. Gonadotropin-releasing hormone analogs (GnRHas) are the gold standard for the treatment of central precocious puberty (CPP) and have an impressive record of safety and efficacy. However, ongoing refinements in diagnosis and management continue to lead to important advancements in clinical care.

AREAS COVERED

The aim of this review is to cover current considerations and controversies regarding the diagnosis of CPP, as well as new findings in regards to etiology and treatment modalities.

EXPERT COMMENTARY

There is emerging evidence of monogenic etiologies of CPP and significant progress in the expansion of newer formulations of GnRHas. Despite these exciting developments, areas of uncertainty in the diagnosis and treatment of CPP remain. While long-term outcomes of patients treated for CPP are encouraging, only short-term follow-up is available with respect to the newer extended release GnRHa preparations, and how they compare with historically used formulations is unknown. A particular shortage of information exists pertaining to CPP in boys and regarding the psychological implications of PP in girls, and more research is needed. Continued investigation will yield new insights into the underlying genetics and optimal treatment strategies for CPP.

Pediatric endocrinology: an overview of the last decade

Over the past decade, considerable progress has been made in the field of pediatric endocrinology. However, there is still a long way to go regarding the exploration of novel avenues, such as epigenetics, the changing views on the pathophysiology and derived therapy of specific disorders, and the prevention of prevalent diseases. The next decade will hopefully bring the consolidation of most of those achievements and the development of new pathways for further progress.

A mathematical model for predicting the adult height of girls with idiopathic central precocious puberty: A European validation

Background

A previous single-center study established a mathematical model for predicting the adult height (AH) in girls with idiopathic central precocious puberty (CPP).

Objective

To perform internal and external validations by comparing the actual AH to the calculated AH established by this model and to update it.

Methods

The original formula, calculated AH (cm) = 2.21 (height at initial evaluation, SD) + 2.32 (target height, SD) - 1.83 (luteinizing hormone/follicle-stimulating hormone peaks ratio) + 159.68, was established in a sample of 134 girls (group 4) and was applied to additional girls with CPP seen in the same center (group 1, n = 35), in Germany (group 2, n = 43) and in the Netherlands (group 3, n = 72). This formula has been updated based on these extended data, and both versions are available at the following location: http://www.kamick.org/lemaire/med/girls-cpp15.html.

Results

Despite the differences among the 4 groups in terms of their characteristics at the initial evaluation and the percentages of patients treated with the gonadotropin-releasing hormone analogue, they have similar calculated and actual AHs. The actual AHs are 162.2±7.0, 163.0±7.6, 162.4±7.7 and 162.1±5.6 cm in groups 1 to 4, respectively. They are highly correlated with the AHs calculated by the formula established in the original group (group 4), with R at 0.84, 0.67 and 0.69 in groups 1 to 3, respectively. When the actual AHs and the AHs predicted by the Bayley and Pinneau method are compared, the R is 0.76, 0.51 and 0.64 in groups 1 to 3, respectively.

The absolute differences between actual AHs and the calculated AHs are greater than 1 SD (5.6 cm) in 15%, 35% and 28% of the patients in groups 1 to 3, respectively.

Conclusion

This study validates and updates the previously established formula for predicting AH in girls with CPP. This updated formula can help clinicians to make treatment decisions.

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.

Central precocious puberty: revisiting the diagnosis and therapeutic management

Clinical and laboratory diagnosis and treatment of central precocious puberty (CPP) remain challenging due to lack of standardization. The aim of this revision was to address the diagnostic and therapeutic features of CPP in Brazil based on relevant international literature and availability of the existing therapies in the country. The diagnosis of CPP is based mainly on clinical and biochemical parameters, and a period of follow-up is desirable to define the "progressive" form of sexual precocity. This occurs due to the broad spectrum of pubertal development, including isolated premature thelarche, constitutional growth and puberty acceleration, progressive and nonprogressive CPP, and early puberty. Measurement of basal and stimulated LH levels remains challenging, considering that the levels are not always in the pubertal range at baseline, short-acting GnRH is not readily available in Brazil, and the cutoff values differ according to the laboratory assay. When CPP is suspected but basal LH values are at prepubertal range, a stimulation test with short-acting or long-acting monthly GnRH is a diagnostic option. In Brazil, the treatment of choice for progressive CPP and early puberty is a long-acting GnRH analog (GnRHa) administered once a month or every 3 months. In Brazil, formulations of GnRHa (leuprorelin and triptorelin) are available and commonly administered, including 1-month depot leuprorelin 3.75 mg and 7.5 mg, 1-month depot triptorelin 3.75 mg, and 3-month depot leuprorelin 11.25 mg. Monthly or 3-month depot GnRHa are effective and safe to treat CPP. Arch Endocrinol Metab. 2016;60(2):163-72.

Causes, diagnosis, and treatment of central precocious puberty

Central precocious puberty results from the premature activation of the hypothalamic-pituitary-gonadal axis. It mimics physiological pubertal development, although at an inappropriate chronological age (before 8 years in girls and 9 years in boys). It can be attributable to cerebral congenital malformations or acquired insults, but the cause in most cases in girls remains unknown. MKRN3 gene defects have been identified in familial disease, with important basic and clinical results. Indeed, genetic analysis of this gene should be included in the routine clinical investigation of familial and idiopathic cases of central precocious puberty. Gonadotropin-releasing hormone agonists are the gold-standard treatment. The assessment and management of this disease remain challenging for paediatric endocrinologists. In this Series paper, we describe current challenges involving the precise diagnosis and adequate treatment of this disorder.

MANAGEMENT OF ENDOCRINE DISEASE: Long-term outcomes of the treatment of central precocious puberty

GnRH analogues (GnRHa) are the treatment of choice for central precocious puberty (CPP), with the main objective to recover the height potential compromised by the premature fusion of growth cartilages. The aim of this review was to analyze long-term effects of GnRHa on height, body weight, reproductive function, and bone mineral density (BMD) in patients with CPP, as well as the potential predictors of outcome. Because randomized controlled trials on the effectiveness and long-term outcomes of treatment are not available, only qualified conclusions about the efficacy of interventions can be drawn. GnRHa treatment appears to improve adult height in girls with CPP, especially if diagnosed before the age of 6, whereas a real benefit in terms of adult height is still controversial in patients with the onset of puberty between 6 and 8 years of age. No height benefit was shown in patients treated after 8 years. Gonadal function is promptly restored in girls after cessation of treatment, and reproductive potential appears normal in young adulthood. Data are conflicting on the long-term risk of polycystic ovarian syndrome in both treated and untreated women. Fat mass is increased at the start of treatment but normalizes thereafter, and GnRHa itself does not seem to have any long-term effect on BMI. Similarly, analogue treatment does not appear to have a negative impact on BMD. Owing to the paucity of data available, no conclusions can be drawn on the repercussions of CPP and/or its treatment on the timing of menopause and on the health of the offspring.

60 YEARS OF NEUROENDOCRINOLOGY: MEMOIR: Harris' neuroendocrine revolution: of portal vessels and self-priming

Geoffrey Harris, while still a medical student at Cambridge, was the first researcher (1937) to provide experimental proof for the then tentative view that the anterior pituitary gland was controlled by the CNS. The elegant studies carried out by Harris in the 1940s and early 1950s, alone and in collaboration with John Green and Dora Jacobsohn, established that this control was mediated by a neurohumoral mechanism that involved the transport by hypophysial portal vessel blood of chemical substances from the hypothalamus to the anterior pituitary gland. The neurohumoral control of anterior pituitary secretion was proved by the isolation and characterisation of the 'chemical substances' (mainly neuropeptides) and the finding that these substances were released into hypophysial portal blood in a manner consistent with their physiological functions. The new discipline of neuroendocrinology - the way that the brain controls endocrine glands and vice versa - revolutionised the treatment of endocrine disorders such as growth and pubertal abnormalities, infertility and hormone-dependent tumours, and it underpins our understanding of the sexual differentiation of the brain and key aspects of behaviour and mental disorder. Neuroendocrine principles are illustrated in this Thematic Review by way of Harris' major interest: hypothalamic-pituitary-gonadal control. Attention is focussed on the measurement of GnRH in hypophysial portal blood and the role played by the self-priming effect of GnRH in promoting the onset of puberty and enabling the oestrogen-induced surge or pulses of GnRH to trigger the ovulatory gonadotrophin surge in humans and other spontaneously ovulating mammals.

Central Precocious Puberty: Update on Diagnosis and Treatment

Central precocious puberty (CPP) is characterized by the same biochemical and physical features as normally timed puberty but occurs at an abnormally early age. Most cases of CPP are seen in girls, in whom it is usually idiopathic. In contrast, ~50% of boys with CPP have an identifiable cause. The diagnosis of CPP relies on clinical, biochemical, and radiographic features. Untreated, CPP has the potential to result in early epiphyseal fusion and a significant compromise in adult height. Thus, the main goal of therapy is preservation of height potential. The gold-standard treatment for CPP is gonadotropin-releasing hormone (GnRH) analogs (GnRHa). Numerous preparations with a range of delivery systems and durations of action are commercially available. While the outcomes of patients treated for CPP have generally been favorable, more research about the psychological aspects, optimal monitoring, and long-term effects of all forms of GnRHa treatment is needed. Several potential therapeutic alternatives to GnRHa exist and await additional investigation.