A Randomized Phase 2 Study of Long-Acting TransCon GH vs Daily GH in Childhood GH Deficiency

Long-acting growth hormone in the treatment of growth hormone deficiency in children: a systematic literature review and network meta-analysis

The purpose of this study is to compare the relative efficacy and safety of long-acting growth hormone (LAGH) as a growth hormone replacement therapy in prepubertal children with growth hormone deficiency (GHD). We searched the PubMed, Embase, CNKI, and Wanfang databases from inception to July 2023 and identified eleven relevant studies. PEG-LAGH showed better effect on height velocity (mean difference [MD]: - 0.031, 95% credibility interval [CrI]: - 0.278, 0.215) than somatrogon (MD: 0.105, 95% CrI: - 0.419, 0.636), somapacitan (MD: 0.802, 95% CrI: - 0.451, 2.068) and lonapegsomatropin (MD: 1.335, 95% CrI: - 0.3, 2.989) when compared with daily growth hormone (DGH). Furthermore, in terms of height standard deviation score, PEG-LAGH demonstrated better improvement (MD: - 0.15, 95% CrI: - 1.1, 0.66) than somatrogon (MD: - 0.055, 95% CrI: - 1.3, 0.51) and somapacitan (MD: 0.22, 95% CrI: - 0.91, 1.3). PEG-LAGH (risk ratio [RR]: 1.00, 95% CrI: 0.82, 1.2) reduced the risk of adverse events compared with other LAGH (somatrogon, RR: 1.1, 95% CrI: 0.98, 1.2; somapacitan, RR: 1.1, 95% CrI: 0.96, 1.4; lonapegsomatropin, RR, 1.1, 95% CrI: 0.91, 1.3) and was comparable with DGH. This is the first study to indirectly compare the LAGH thorough a network meta-analysis and provide evidence of the optimal efficacy of various LAGH specifically PEG-LAGH and acceptable safety profile in prepubertal children with GHD.

Growth hormone receptor agonists and antagonists: From protein expression and purification to long-acting formulations

Recombinant human growth hormone (rhGH) and GH receptor antagonists (GHAs) are used clinically to treat a range of disorders associated with GH deficiency or hypersecretion, respectively. However, these biotherapeutics can be difficult and expensive to manufacture with multiple challenges from recombinant protein generation through to the development of long-acting formulations required to improve the circulating half-life of the drug. In this review, we summarize methodologies and approaches used for making and purifying recombinant GH and GHA proteins, and strategies to improve pharmacokinetic and pharmacodynamic properties, including PEGylation and fusion proteins. Therapeutics that are in clinical use or are currently under development are also discussed.

Comparing Dose-dependent Outcomes of Weekly and Daily Growth Hormone Therapy in Children with Growth Hormone Deficiency: A Systematic Review and Meta-analysis.. [DOI: 10.21203/rs.3.rs-3123741/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Growth hormone deficiency (GHD) is a condition impacting children and adults, leading to low height and other health issues. The primary treatment is daily injections of recombinant human growth hormone (rhGH), though they can be inconvenient and costly. These injections may also negatively impact treatment adherence and outcomes. This study aims to compare the efficacy and safety of once-weekly growth hormone treatment vs daily growth hormone therapy in children with growth hormone insufficiency. Methods To examine the efficacy and safety of once-weekly and once-daily growth hormone treatment for children with growth hormone insufficiency, this meta-analysis followed PRISMA and Cochrane standards. RCTs and prospective cohort studies with children aged 0–18 diagnosed with GHD were considered eligible. We used the risk of bias 2 and the certainty of evidence using the Cochrane tools. Two authors independently assessed papers for eligibility and extracted data after conducting a thorough search of electronic resources. Height velocity, height standard deviation score, insulin-like growth factor 1 levels, and the incidence of adverse events were the primary outcomes. The Revman software version 5.4 was used for data synthesis, and heterogeneity was determined by I-squares greater than 60%. Results This meta-analysis and comprehensive review includes 14 randomized clinical trials and one study was cohort, including 1,322 children with growth hormone insufficiency. Weekly growth hormone treatment at dosages ranging from 0.11 to 0.25 mg enhanced a variety of growth outcomes, including increased height velocity dose (SMD = 0.37, 95% CI, 0.23–0.51; P < 0.001), height standard deviation scores chronological age (SMD= -0.10, 95% CI, -0.13–0.07; P < 0.001), and insulin-like growth factor 1 standard deviation score (SMD = 0.41, 95% CI, 0.40–0.42; P < 0.001). The dosage range of 0.26 to 0.50 mg also improved insulin-like growth factor binding protein-3 significantly (SMD= -0.63, 95% CI, -0.90 – -0.37; P < 0.001). Nevertheless, there were no significant differences in the occurrence of adverse events through the dosage levels (OR = 0.71, 95% CI 0.36 to 1.40; P = 0.32). Conclusions In children with growth hormone deficit, weekly growth hormone treatment, particularly in the 0.11 to 0.25 mg dose range, can function as a viable alternative to daily growth hormone therapy.

Efficacy, safety, quality of life, adherence and cost-effectiveness of long-acting growth hormone replacement therapy compared to daily growth hormone in children with growth hormone deficiency: a systematic review and meta-analysis

We evaluated the efficacy, safety, adherence, quality of life (QoL) and cost-effectiveness of long-acting growth hormone (LAGH) vs daily growth hormone (GH) preparations in the treatment of growth hormone deficiency (GHD) in children. Systematic searches were performed in PubMed, Embase and Web of Science up to July 2022 on randomized and non-randomized studies involving children with GHD receiving LAGH as compared to daily GH. Meta-analyses for efficacy and safety were performed comparing different LAGH/daily GH formulations. From the initial 1,393 records, we included 16 studies for efficacy and safety, 8 studies for adherence and 2 studies for QoL. No studies reporting cost-effectiveness were found. Pooled mean differences of mean annualized height velocity (cm/year) showed no difference between LAGH and daily GH: Eutropin Plus® vs Eutropin® [-0.14 (-0.43, 0.15)], Eutropin Plus® vs Genotropin® [-0.74 (-1.83, 0.34)], Jintrolong® vs Jintropin AQ® [0.05 (-0.54, 0.65)], Somatrogon vs Genotropin® [-1.40 (-2.91, 0.10)], TransCon vs Genotropin® [0.93 (0.26, 1.61)]. Also, other efficacy and safety outcomes, QoL and adherence were comparable for LAGH and daily GH. Our results showed that, although most of the included studies had some concerns for risk of bias, regarding efficacy and safety all the LAGH formulations were similar to daily GH. Future high quality studies are needed to confirm these data. Adherence and QoL should be addressed from real-world data studies for both the mid and long term and in a larger population. Cost-effectiveness studies are needed to measure the economic impact of LAGH from the healthcare payer's perspective.

Weekly Growth Hormone (Lonapegsomatropin) Causes Severe Transient Hyperglycemia in a Child with Obesity

INTRODUCTION

A 12-year-and-9-month-old non-Hispanic black male with a history of growth hormone deficiency, pituitary hypoplasia, prediabetes, obesity, hypertension, and hyperlipidemia was initiated on weekly growth hormone (lonapegsomatropin-tcgd) and then transiently developed symptomatic hyperglycemia to 500 mg/dL. We aimed to describe this medication's effect.

CASE PRESENTATION

He was born full term and appropriate for gestational age. He was referred to endocrinology at 3.5 years of age for short stature with a height SDS of -2.48. IGF-1 51.1 ng/mL and IGFBP-3 1.2 ng/mL were low. GH stimulation test noted baseline and peak GH of 0.1 ng/mL. MRI brain showed hypoplastic adenohypophysis, aplastic pituitary stalk, and ectopic neurohypophysis. There had been difficulty with adherence to daily GH over the following 9 years. BMI trajectory rose above 180% of the 95th percentile. By age 12, A1c was 6.6%. Metformin was started and increased to 1,000 mg twice daily. Subsequent A1c was 6.0%. Due to poor compliance with daily GH, at 12 years and 9 months, he was initiated on 22 mg (0.25 mg/kg/week) of weekly lonapegsomatropin-tcgd to improve compliance. The day after his first injection, he developed non-bloody, non-bilious emesis. He denied headaches and endorsed polyuria. Due to concern for increased intracranial pressure, he was sent to the emergency department; however, ophthalmologic exam was negative. Initial serum glucose was 500 mg/dL, then 336 mg/dL after 1-L normal saline. Hemoglobin A1c was 5.7%, urine glucose 3+ mg/dL, and urine ketones 2+ mg/dL. Venous pH of 7.379 and bicarbonate of 20.6 mmol/L ruled out diabetic ketoacidosis. Metformin was held during the hospitalization. Hyperglycemia rapidly improved with transient insulin administration. He received one dose of glargine 20 units. He was initiated on lispro carb ratio of 1:8 and correction factor 1:15 for target glucose 150 mg/dL. By day four, glucoses were below 100 mg/dL; lispro was discontinued, and he was discharged home. Weekly GH was discontinued with plans to resume daily GH therapy in several months.

CONCLUSION

Lonapegsomatropin-tcgd offers the convenience of weekly rather than daily GH treatment; however, this patient developed a rapid increase in insulin resistance and hyperglycemia requiring insulin. The discrepancy between the glucose of 500 mg/dL and A1c of 5.7%, along with the rapid resolution of hyperglycemia, is further consistent with a medication side effect. Close glucose monitoring of patients initiated on weekly growth hormone is crucial, particularly in those with a history of prediabetes.

Weekly Somapacitan is Effective and Well Tolerated in Children With GH Deficiency: The Randomized Phase 3 REAL4 Trial

CONTEXT

Somapacitan, a once-weekly reversible albumin-binding GH derivative, is evaluated in children with GH deficiency (GHD).

OBJECTIVE

To demonstrate efficacy and safety of somapacitan vs daily GH.

METHODS

REAL4 is a randomised, multinational, open-labeled, active-controlled parallel group phase 3 trial, comprising a 52-week main trial and 3-year extension (NCT03811535).

SETTING

Eighty-six sites across 20 countries.

PATIENTS

200 treatment-naïve patients were randomized and exposed.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (Norditropin; 0.034 mg/kg/d), administered subcutaneously.

MAIN OUTCOME MEASURES

The primary endpoint was annualized height velocity (HV; cm/y) at week 52. Additional assessments included HV SD score (SDS), height SDS, bone age, IGF-I SDS, patient-reported outcomes, and safety measures.

RESULTS

Estimated mean HV at week 52 was 11.2 and 11.7 cm/y for somapacitan and daily GH, respectively. Noninferiority was confirmed. Changes in HV SDS, height SDS, bone age, and IGF-I SDS from baseline to week 52 were similar between treatment groups. At week 52, mean IGF-I SDS values were similar between treatment groups and within normal range (-2 to +2). Safety of somapacitan was consistent with the well-known daily GH profile. Low proportions of injection-site reactions were reported for somapacitan (5.3%) and daily GH (5.9%). Both treatments similarly reduced disease burden from baseline to week 52, whereas a greater treatment burden reduction was observed for somapacitan.

CONCLUSIONS

Similar efficacy for somapacitan compared to daily GH was demonstrated over 52 weeks of treatment with comparable safety and mean IGF-I SDS levels in treatment-naïve children with GHD.

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

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

Safety and Efficacy of Lonapegsomatropin in Children With Growth Hormone Deficiency: enliGHten Trial 2-Year Results

PURPOSE

The objectives of the ongoing, Phase 3, open-label extension trial enliGHten are to assess the long-term safety and efficacy of weekly administered long-acting growth hormone lonapegsomatropin in children with growth hormone deficiency.

METHODS

Eligible subjects completing a prior Phase 3 lonapegsomatropin parent trial (heiGHt or fliGHt) were invited to participate. All subjects were treated with lonapegsomatropin. Subjects in the United States switched to the TransCon hGH Auto-Injector when available. Endpoints were long-term safety, annualized height velocity, pharmacodynamics [insulin-like growth factor-1 SD score (SDS) values], and patient- and caregiver-reported assessments of convenience and tolerability.

RESULTS

Lonapegsomatropin treatment during enliGHten was associated with continued improvements in height SDS through week 104 in treatment-naïve subjects from the heiGHt trial (-2.89 to -1.37 for the lonapegsomatropin group; -3.0 to -1.52 for the daily somatropin group). Height SDS also continued to improve among switch subjects from the fliGHt trial (-1.42 at fliGHt baseline to -0.69 at week 78). After 104 weeks, the average bone age/chronological age ratio for each treatment group was 0.8 (0.1), showing only minimal advancement of bone age relative to chronological age with continued lonapegsomatropin treatment among heiGHt subjects. Fewer local tolerability reactions were reported with the TransCon hGH Auto-Injector compared with syringe/needle.

CONCLUSIONS

Treatment with lonapegsomatropin continued to be safe and well-tolerated, with no new safety signals identified. Children treated with once-weekly lonapegsomatropin showed continued improvement of height SDS through the second year of therapy without excess advancement of bone age.

Polymer-drug conjugates: Design principles, emerging synthetic strategies and clinical overview

Adagen, an enzyme replacement treatment for adenosine deaminase deficiency, was the first protein-polymer conjugate to be approved in early 1990s. Post this regulatory approval, numerous polymeric drugs and polymeric nanoparticles have entered the market as advanced or next-generation polymer-based therapeutics, while many others have currently been tested clinically. The polymer conjugation to therapeutic moiety offers several advantages, like enhanced solubilization of drug, controlled release, reduced immunogenicity, and prolonged circulation. The present review intends to highlight considerations in the design of therapeutically effective polymer-drug conjugates (PDCs), including the choice of linker chemistry. The potential synthetic strategies to formulate PDCs have been discussed along with recent advancements in the different types of PDCs, i.e., polymer-small molecular weight drug conjugates, polymer-protein conjugates, and stimuli-responsive PDCs, which are under clinical/preclinical investigation. Current impediments and regulatory hurdles hindering the clinical translation of PDC into effective therapeutic regimens for the amelioration of disease conditions have been addressed.

Long-acting recombinant human growth hormone in the treatment of pediatric growth hormone deficiency, how far have we got?

The widespread availability of recombinant human growth hormone (GH) since 1985 has made it possible to extend growth hormone therapy indications for children with different etiologies of short stature. It is now accepted that GH is effective in increasing height velocity in children with GH deficiency (GHD) and well tolerated in both the short and long terms. Nevertheless, one major factor in the inter-individual variability of the growth response to GH in GHD children is adherence to daily injections. In an attempt to improve patient adherence, there has been a strong effort from industry to create a long-acting form of growth hormone to ease the burden of its use. It is theorized that by decreasing injection frequency, Long-Acting GH (LAGH) would improve adherence and therefore outcomes. These agents can be divided broadly into depot formulations, PEGylated formulations, prodrug formulations, noncovalent albumin-binding GH and GH fusion proteins. In 2021, two LAGH formulations are on the market in China and South Korea, and several promising agents are under clinical investigation at various stages of development throughout the world. A number of safety issues related to LAGH have been identified and need to be further investigated. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

TransCon human growth hormone for children with growth hormone deficiency: a technology evaluation

INTRODUCTION

Standard-of-care treatment for growth hormone deficiency consists of daily subcutaneous injections of recombinant human growth hormone, also known as somatropin. Although somatropin treatment is well established, the burden of daily injections can lead to poor adherence and quality of life. In this regard, a TransCon human growth hormone (lonapegsomatropin-tcgd) technology was developed to optimize the therapeutic effect of daily somatropin for the treatment of children with growth hormone deficiency.

AREAS COVERED

The authors reviewed the effects of lonapegsomatropin-tcgd in children with growth hormone deficiency.

EXPERT OPINION

Lonapegsomatropin-tcgd was found to be non-inferior to and superior to daily somatropin for annualized height velocity. In addition, the safety was comparable between them. As a result, the convenient dosing of lonapegsomatropin-tcgd has the potential to improve patient adherence, leading to increased efficacy and quality of life. Medication adherence, quality of life, long-term safety, and cost-effectiveness studies comparing lonapegsomatropin-tcgd and daily somatropin are required to confirm these possible benefits.

Average IGF-1 Prediction for Once-Weekly Lonapegsomatropin in Children With Growth Hormone Deficiency

CONTEXT

Serum insulin-like growth factor 1 (IGF-1) levels are relatively constant in somatropin-treated children with growth hormone deficiency (GHD), and guide dose adjustments for clinical efficacy and long-term safety. IGF-1 levels following treatment with long-acting growth hormones such as lonapegsomatropin (lonapegsomatropin-tcgd, TransCon hGH), a once-weekly somatropin prodrug, exhibit a characteristic profile over the dosing interval.

OBJECTIVE

This study aimed to develop a method to predict average IGF-1 in lonapegsomatropin-treated GHD children to interpret IGF-1 data based on a single sample obtained any time at steady state.

METHODS

A population nonlinear mixed-effect pharmacodynamic model for IGF-1 was developed based on 2 randomized, open-label trials of TransCon hGh in GHD children and used to develop a linear mixed model with Taylor series to fit simulated IGF-1 profiles of lonapegsomatropin-treated children.

A TOTAL OF

49 896 IGF-1 sample data simulated from 105 lonapegsomatropin-treated GHD children were utilized for the final prediction model. The dosage range of TransCon hGh was 0.14 to 0.30 hGH mg/kg/week, and weekly average IGF-1 was calculated using IGF-1 profiles simulated from the nonlinear pharmacodynamic model. Predicted average IGF-1 was obtained by linear mixed model with Taylor series.

RESULTS

The nonlinear mixed-effect model provided satisfactory model fit. The linear mixed model with Taylor series fit simulated IGF-1 data well, with a relatively straightforward prediction formula. IGF-1 values sampled at ~4.5 days post-dose coincided with weekly average IGF-1 at steady state.

CONCLUSION

A formula to predict average IGF-1 from a single sample of IGF-1 at steady state was established to aid clinicians in interpreting IGF-1 levels in GHD children administered lonapegsomatropin.

Lonapegsomatropin: Pediatric First Approval

Lonapegsomatropin (lonapegsomatropin-tcgd; SKYTROFA^®), a long-acting prodrug of somatropin (human growth hormone), is in development by Ascendis Pharma as a treatment for growth hormone deficiency in pediatric and adult patients. Lonapegsomatropin received its first approval in August 2021 in the USA for the treatment of pediatric patients at least 1 year of age (and weighing ≥ 11.5 kg) with growth failure due to inadequate secretion of endogenous growth hormone. Lonapegsomatropin is administered as a once-weekly subcutaneous injection; the sustained release of somatropin from lonapegsomatropin eliminates the need for daily somatropin injections. This article summarizes the milestones in the development of lonapegsomatropin leading to this first pediatric approval for the treatment of growth hormone deficiency.

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

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

Effect of Weekly Long-Acting Growth Hormone Replacement Therapy Compared to Daily Growth Hormone on Children With Short Stature: A Meta-Analysis

Background

We performed a meta-analysis to evaluate the efficacy and safety of weekly long-acting growth hormone replacement therapy compared to daily growth hormone in children with short stature.

Methods

A systematic literature search up to April 2021 was performed and 11 studies included 1,232 children with short stature treated with growth hormone replacement therapy at the start of the study; 737 of them were using weekly long-acting growth hormone replacement therapy and 495 were using daily growth hormone. They were reporting relationships between the efficacy and safety of long-acting growth hormone replacement therapy and daily growth hormone in children with short stature. We calculated the odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) to assess the efficacy and safety of weekly long-acting growth hormone replacement therapy compared to daily growth hormone in children with short stature using the dichotomous or continuous method with a random or fixed-effect model.

Results

Long-acting growth hormone replacement therapy had significantly lower height standard deviation scores chronological age (MD, -0.10; 95% CI, -0.13 to -0.08, p <0.001), and insulin-like growth factor binding protein-3 (MD, -0.69; 95% CI, -1.09 to -0.30, p <0.001) compared to daily growth hormone in children with short stature.However, growth hormone replacement therapy had no significantly difference in height velocity (MD, -0.09; 95% CI, -0.69-0.5, p = 0.76), height standard deviation scores bone age (MD, -0.04; 95% CI, -0.10-0.02, p = 0.16), insulin-like growth factor 1 standard deviation scores (MD, 0.26; 95% CI, -0.26-0.79, p = 0.33), and incidence of adverse events (OR, 1.16; 95% CI, 0.90-1.50, p = 0.25) compared to daily growth hormone in children with short stature.

Conclusions

Long-acting growth hormone replacement therapy had significantly lower height standard deviation scores chronological age, and insulin-like growth factor binding protein-3 compared to daily growth hormone in children with short stature. However, growth hormone replacement therapy had no significant difference in height velocity, height standard deviation scores bone age, insulin-like growth factor 1 standard deviation scores, and incidence of adverse events compared to daily growth hormone in children with short stature. Further studies are required to validate these findings.

Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial

CONTEXT

For children with growth hormone deficiency (GHD), treatment burden with daily somatropin injections [human growth hormone (hGH)] is high, which may lead to poor adherence and suboptimal overall treatment outcomes. Lonapegsomatropin (TransCon hGH) is an investigational long-acting, once-weekly prodrug for the treatment of GHD.

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of once-weekly lonapegsomatropin vs daily somatropin.

DESIGN

The heiGHt trial was a randomized, open-label, active-controlled, 52-week Phase 3 trial (NCT02781727).

SETTING

This trial took place at 73 sites across 15 countries.

PATIENTS

This trial enrolled and dosed 161 treatment-naïve, prepubertal patients with GHD.

INTERVENTIONS

Patients were randomized 2:1 to receive lonapegsomatropin 0.24 mg hGH/kg/week or an equivalent weekly dose of somatropin delivered daily.

MAIN OUTCOME MEASURE

The primary end point was annualized height velocity (AHV) at week 52. Secondary efficacy end points included change from baseline in height SD scores (SDS).

RESULTS

Least squares (LS) mean (SE) AHV at 52 weeks was 11.2 (0.2) cm/year for lonapegsomatropin vs 10.3 (0.3) cm/year for daily somatropin (P = 0.009), with lonapegsomatropin demonstrating both noninferiority and superiority over daily somatropin. LS mean (SE) height SDS increased from baseline to week 52 by 1.10 (0.04) vs 0.96 (0.05) in the weekly lonapegsomatropin vs daily somatropin groups (P = 0.01). Bone age/chronological age ratio, adverse events, tolerability, and immunogenicity were similar between groups.

CONCLUSIONS

The trial met its primary objective of noninferiority in AHV and further showed superiority of lonapegsomatropin compared to daily somatropin, with similar safety, in treatment-naïve children with GHD.

A review of existing strategies for designing long-acting parenteral formulations: Focus on underlying mechanisms, and future perspectives

The need for long-term treatments of chronic diseases has motivated the widespread development of long-acting parenteral formulations (LAPFs) with the aim of improving drug pharmacokinetics and therapeutic efficacy. LAPFs have been proven to extend the half-life of therapeutics, as well as to improve patient adherence; consequently, this enhances the outcome of therapy positively. Over past decades, considerable progress has been made in designing effective LAPFs in both preclinical and clinical settings. Here we review the latest advances of LAPFs in preclinical and clinical stages, focusing on the strategies and underlying mechanisms for achieving long acting. Existing strategies are classified into manipulation of in vivo clearance and manipulation of drug release from delivery systems, respectively. And the current challenges and prospects of each strategy are discussed. In addition, we also briefly discuss the design principles of LAPFs and provide future perspectives of the rational design of more effective LAPFs for their further clinical translation.

Human Growth and Growth Hormone: From Antiquity to the Recominant Age to the Future

Since antiquity Man has been fascinated by the variations in human (and animal) growth. Stories and art abound about giants and little people. Modern genetics have solved some of etiologies at both extremes of growth. Serious study began with the pathophysiology of acromegaly followed by early attempts at treatment culminating in modern endoscopic surgery and multiple pharmacologic agents. Virtually at the same time experiments with the removal of the pituitary from laboratory animals noted the slowing or stopping of linear growth and then over a few decades the extraction and purification of a protein within the anterior pituitary that restored, partially or in full, the animal's growth. Human growth hormone was purified decades after those from large animals and it was noted that it was species specific, that is, only primate growth hormone was metabolically active in primates. That was quite unlike the beef and pork insulins which revolutionized the care of children with diabetes mellitus. A number of studies included mild enzymatic digestion of beef growth hormone to determine if those "cores" had biologic activity in primates and man. Tantalizing data showed minimal but variable metabolic efficacy leading to the "active core" hypothesis, for these smaller peptides would be amenable to peptide synthesis in the time before recombinant DNA. Recombinant DNA changed the landscape remarkably promising nearly unlimited quantities of metabolically active hormone. Eight indications for therapeutic use have been approved by the Food and Drug Administration and a large number of clinical trials have been undertaken in multiple other conditions for which short stature in childhood is a sign. The future predicts other clinical indications for growth hormone therapy (and perhaps other components of the GH?IGF-1 axis), longer-acting analogues and perhaps a more physiologic method of administration as virtually all methods at present are far from physiologic.

Development of a Predictive Enrichment Marker for the Oral GH Secretagogue LUM-201 in Pediatric Growth Hormone Deficiency

Context

We hypothesize, based on the degree of residual hypothalamic-pituitary function, that some, but not all, children with growth hormone deficiency (GHD) may have beneficial growth responses to the orally administered growth hormone (GH) secretagogue LUM-201.

Objective

To determine if pretreatment testing can identify predictive enrichment markers (PEM) for subjects with adequate residual function who are responsive to LUM-201.

Methods

We performed an analysis of a completed, randomized, placebo-controlled trial of LUM-201, a GH secretagogue receptor agonist, in which all randomized subjects had pretreatment testing.

This international multicenter study conducted in pediatric endocrinology clinics included 68 naïve-to-treatment, prepubertal children with established diagnoses of GHD. Outcome measures included the sensitivity, specificity, and predictive accuracy of potential markers to predict 6-month growth responses to oral LUM-201 and daily rhGH.

Results

Two PEM were identified for use in defining PEM-positive status: (1) baseline insulin-like growth factor I (IGF-I) concentration >30 ng/mL and (2) peak GH response of ≥5 ng/mL upon administration of single-dose LUM-201. PEM-positive status enriches a population for better growth responses to LUM-201. PEM-negative status enriches a population for better growth responses to rhGH.

Conclusion

Combined, the peak GH response to single-dose LUM-201 and the baseline IGF-I concentration are effective PEMs for 6-month growth responses to LUM-201 and rhGH in prepubertal children with GHD.

Usefulness and Potential Pitfalls of Long-Acting Growth Hormone Analogs

Daily recombinant human GH (rhGH) is currently approved for use in children and adults with GH deficiency (GHD) in many countries with relatively few side-effects. Nevertheless, daily injections can be painful and distressing for some patients, often resulting in non-adherence and reduction of treatment outcomes. This has prompted the development of numerous long-acting GH (LAGH) analogs that allow for decreased injection frequency, ranging from weekly, bi-weekly to monthly. These LAGH analogs are attractive as they may theoretically offer increased patient acceptance, tolerability, and therapeutic flexibility. Conversely, there may also be pitfalls to these LAGH analogs, including an unphysiological GH profile and differing molecular structures that pose potential clinical issues in terms of dose initiation, therapeutic monitoring, incidence and duration of side-effects, and long-term safety. Furthermore, fluctuations of peak and trough serum GH and IGF-I levels and variations in therapeutic efficacy may depend on the technology used to prolong GH action. Previous studies of some LAGH analogs have demonstrated non-inferiority compared to daily rhGH in terms of increased growth velocity and improved body composition in children and adults with GHD, respectively, with no significant unanticipated adverse events. Currently, two LAGH analogs are marketed in Asia, one recently approved in the United States, another previously approved but not marketed in Europe, and several others proceeding through various stages of clinical development. Nevertheless, several practical questions still remain, including possible differences in dose initiation between naïve and switch-over patients, methodology of dose adjustment/s, timing of measuring serum IGF-I levels, safety, durability of efficacy and cost-effectiveness. Long-term surveillance of safety and efficacy of LAGH analogs are needed to answer these important questions.

Challenges and opportunities in the delivery of cancer therapeutics: update on recent progress

Global cancer prevalence has continuously increased in the last decades despite substantial progress achieved for patient care. Cancer is no longer recognized as a singular disease but as a plurality of different ones, leading to the important choice of the drug administration route and promoting the development of novel drug-delivery systems (DDS). Due to their structural diversity, therapeutic cancer drugs present specific challenges in physicochemical properties that can adversely affect their efficacy and toxicity profile. These challenges are addressed by innovative DDS to improve bioavailability, pharmacokinetics and biodistribution profiles. Here, we define the drug delivery challenges related to oral, intravenous, subcutaneous or alternative routes of administration, and review innovative DDS, marketed or in development, that answer those challenges.

Clinically established biodegradable long acting injectables: An industry perspective

Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.

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

CONTEXT

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

METHODS

Recent literature and meeting proceedings regarding LAGH preparations are reviewed.

RESULTS

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

CONCLUSION

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

Management of Hypopituitarism

Hypopituitarism includes all clinical conditions that result in partial or complete failure of the anterior and posterior lobe of the pituitary gland’s ability to secrete hormones. The aim of management is usually to replace the target-hormone of hypothalamo-pituitary-endocrine gland axis with the exceptions of secondary hypogonadism when fertility is required, and growth hormone deficiency (GHD), and to safely minimise both symptoms and clinical signs. Adrenocorticotropic hormone deficiency replacement is best performed with the immediate-release oral glucocorticoid hydrocortisone (HC) in 2–3 divided doses. However, novel once-daily modified-release HC targets a more physiological exposure of glucocorticoids. GHD is treated currently with daily subcutaneous GH, but current research is focusing on the development of once-weekly administration of recombinant GH. Hypogonadism is targeted with testosterone replacement in men and on estrogen replacement therapy in women; when fertility is wanted, replacement targets secondary or tertiary levels of hormonal settings. Thyroid-stimulating hormone replacement therapy follows the rules of primary thyroid gland failure with L-thyroxine replacement. Central diabetes insipidus is nowadays replaced by desmopressin. Certain clinical scenarios may have to be promptly managed to avoid short-term or long-term sequelae such as pregnancy in patients with hypopituitarism, pituitary apoplexy, adrenal crisis, and pituitary metastases.

Adult growth hormone deficiency: clinical advances and approaches to improve adherence

Introduction: There have been significant clinical advances in the understanding of the diagnosis and benefits of long-term recombinant human growth hormone (rhGH) replacement in adults with GH deficiency (GHD) since its approval in 1996 by the United States Food and Drug Administration.Areas covered: We searched PubMed, Medline, CINAHL, EMBASE and PsychInfo databases between January 2000 and June 2019 for published studies evaluating adults with GHD. We reviewed the data of the oral macimorelin test compared to the GHRH plus arginine and the insulin tolerance tests that led to its approval by the United States FDA and European Medicines Agency for adult diagnostic testing. We summarize the clinical advances of long-term benefits of rhGH therapy and the potential effects of GH receptor polymorphisms on individual treatment responsiveness. We identify that non-adherence and discontinuation rates are high and recommend strategies to support patients to improve adherence. We also provide an overview of several long-acting GH (LAGH) preparations currently under development and their potential role in improving treatment adherence.Expert opinion: This article summarizes recent clinical advances in rhGH replacement therapy, the biological and molecular aspects that may influence rhGH action, and offers practical strategies to enhance adherence in adults with GHD.

Perspectives on long-acting growth hormone therapy in children and adults

Growth hormone therapy with daily injections of recombinant human growth hormone has been available since 1985, and is shown to be safe and effective treatment for short stature in children and for adult growth hormone deficiency. In an effort to produce a product that would improve patient adherence, there has been a strong effort from industry to create a long acting form of growth hormone to ease the burden of use. Technologies used to increase half-life include depot formulations, PEGylated formulations, pro-drug formulations, non-covalent albumin binding growth hormone and growth hormone fusion proteins. At present, two long acting formulations are on the market in China and South Korea, and several more promising agents are under clinical investigation at various stages of development throughout the world. Arch Endocrinol Metab. 2019;63(6):601-7.

Efficacy and safety of long-acting growth hormone in children with short stature: a systematic review and meta-analysis

PURPOSE

Long-acting growth hormone (GH) has been developed to address the noncompliance and decreased efficacy associated with daily GH injections. We aimed to evaluate the efficacy and safety of long-acting GH replacement therapy in children with short stature.

METHODS

Randomized controlled trials (RCTs) that investigated the efficacy and safety of long-acting GH therapy in children with short stature in comparison with daily GH injections were searched in Medline, Embase, and the Cochrane Central Register of Controlled Trials. A random-effect model was used to pool data using mean difference and odds ratios (OR). (PROSPERO registration number: CRD42018111105).

RESULTS

Seven relevant studies were finally included. Meta-analysis found there was no significant difference between high-dose long-acting GH and daily GH in terms of height velocity (HV) (mean difference (MD) = -0.10, 95% CI, -0.79 to 0.60, P = 0.79). Moreover, no significant difference was observed in height standard deviation scores (Ht SDS) between high-dose long-acting GH and daily GH (MD = -0.07, 95% CI, -0.18 to 0.03, P = 0.17). Treatment with high-dose long-acting GH significantly increased IGF-1 SDS when compared with daily GH (MD = 0.31, 95% CI, 0.06-0.56, P = 0.02). In safety assessment, no significant difference was observed in the incidence of adverse events between high-dose long-acting GH and daily GH (OR 1.42, 95% CI, 0.65-3.11, P = 0.38).

CONCLUSIONS

There is no evidence to support differences in the effects of long-acting GH compared with those of daily GH. More RCTs that focus on the safety of high-dose long-acting GH treatment, especially the detection of adverse events caused by elevated levels of serum IGF-1, are needed in the future.

Long-Acting Growth Hormone Preparations in the Treatment of Children

Human growth hormone (hGH), which had been in use since 1958, was supplanted by recombinant human growth hormone (rhGH) in 1985 for those with growth hormone deficiency (GHD). Adherence to daily subcutaneous growth hormone is challenging for patients. Thus, several companies have pursued the creation of long acting rhGH. These agents can be divided broadly into depot formulations, PEGylated formulations, pro-drug formulations, non-covalent albumin binding GH and GH fusion proteins. Nutropin Depot is the only long acting rhGH ever approved by the U.S. Food and Drug Administration, and it was removed from the market in 2004. Of the approximately seventeen candidate drugs, only a handful remain under active clinical investigation or are commercially available.

GH and IGF-1 Replacement in Children

In this chapter, we want to give an overview on what we have learned from more than 30 years ago on the use of recombinant human growth hormone (rhGH) and later recombinant human IGF-1 which was introduced for the treatment of short children and what are the safety issues concerned with this treatment. However, rhGH is used not solely in conditions where short stature is the consequence of GH deficiency but also in various disorders without a proven GH deficiency. In clinical studies, growth responses to various forms of rhGH therapy were analyzed, adding to our concept about the physiology of growth. Most patients under rhGH treatment show a considerable short-term effect; however, the long-term gain of height in a child obtained by a year-long treatment until final height remains controversial in some of the growth disorders that have been treated with rhGH or IGF-1. Today the first studies on the long-term safety of rhGH treatment have been published and raising some questions whether this treatment is similarly safe for all the patient groups treated with rhGH. Although there is a long-standing safety record for these hormone replacement therapies, in the face of the considerable costs involved, the discussion about the risk to benefit ratio is continuing. Newer developments of rhGH treatment include long-term preparations, which have only to be injected once a week. Although some of these drugs already have proven their non-inferiority to conventional rhGH treatment, we have to await further results to see whether they show improvements in treatment adherence of the patients and prove their long-term safety.

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.

The current state of long-acting growth hormone preparations for growth hormone therapy

PURPOSE OF REVIEW

To discuss the rationale of developing long-acting growth hormone (LAGH) preparations, to describe the technologies designed to prolong GH action, and to address key issues regarding efficacy, safety, and monitoring while on treatment.

REVIEW FINDINGS

Recombinant human GH is currently approved for daily use and has been shown to restore longitudinal growth, and improve body composition with relatively few side-effects in children and adults with GH deficiency, respectively. However, daily injections can be inconvenient, painful and distressing for some patients, resulting in decreased adherence and efficacy. Over a dozen pharmaceutical companies have designed LAGH preparations that are at various stages of development using a number of different methods to prolong GH action.

SUMMARY

LAGH will represent an advancement over daily recombinant human GH injections because of fewer injections that may offer increased acceptance, tolerability, and therapeutic flexibility to patients that potentially can improve treatment outcomes. However, given the unphysiological profile of LAGH preparations, long-term surveillance of efficacy and safety are needed. This review summarizes recent developments of LAGH preparations, and highlights the importance of long-term surveillance registries to assess for efficacy and safety that will be essential for understanding the impact of prolonged exposure to these compounds.

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

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