Similar safety and efficacy in previously treated adults with growth hormone deficiency randomized to once-weekly somapacitan or daily growth hormone

Efficacy, safety, and patient satisfaction of norditropin and sogroya in patients with growth hormone deficiency: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Growth hormone deficiency occurs when the pituitary gland does not produce enough growth hormone. Norditropin®, a recombinant human growth hormone, and Sogroya®, an albumin-binding growth hormone derivative, are prescribed for patients with growth hormone deficiency. This systematic review assesses the efficacy, safety, and patient satisfaction associated with Norditropin and Sogroya.

METHODS

We systematically searched PubMed, Web of Science, and Scopus databases to identify eligible comparative studies. All studies published until June 2023 were included in our analysis. Our outcomes for children included height velocity and height velocity standard deviation score. In contrast, adult outcomes included adverse events, insulin-like growth factor 1-standard deviation score (IGF-1 SDS), and the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9). Results are reported as odds ratio (OR) and mean difference (MD) with a 95% confidence interval (95% CI).

RESULTS

Ten studies involving 1058 participants (665 children and 393 adults) were included in the meta-analysis. In children, Norditropin at doses of 0.034 and 0.067 mg/kg/day was compared to Sogroya at doses of 0.04, 0.08, 0.16, and 0.24 mg/kg/week. The results showed that 0.034 mg/kg/day Norditropin had a favorable impact on height velocity (MD -2.01, 95% CI -3.7 to -2.12, p < 0.00001) and height velocity standard deviation score (Mean Difference -3.61, 95% CI -5.06 to -2.16, p < 0.00001) when compared to Sogroya 0.04 mg/kg/day. Other doses showed comparable results. In adults, the only significant side effect noted was rash, which favored Sogroya (OR 0.1, 95% CI 0.04-0.27, p < 0.00001). Additionally, IGF-1 SDS was significantly higher in the Sogroya group than in the Norditropin group (MD 0.25, 95% CI 0.02-0.48, p = 0.03). Furthermore, the overall score of the TSQM-9 questionnaire, which includes three domains: convenience, effectiveness, and satisfaction, was significantly higher in the Sogroya group compared to the Norditropin group (OR 6.36, 95% CI 3.92-8.8, p < 0.00001).

CONCLUSION

Norditropin and Sogroya showed comparable efficacy and safety profiles, except for the prevalence of rash in the Norditropin group, and Sogroya has higher satisfaction among adults. More high-quality studies with more patients are required to confirm these results.

Utilizing Somapacitan, a Long-acting Growth Hormone Formulation, for the Treatment of Adult Growth Hormone Deficiency: A Guide for Clinicians

OBJECTIVE

Somapacitan is the first approved and currently the only long-acting growth hormone (GH) formulation in the United States for treatment of adults with growth hormone deficiency (GHD). The aim of this review was to provide a practical approach for clinicians on how to utilize somapacitan in the treatment of adults with GHD.

METHODS

Literature search was performed on PubMed using key words, including adult GHD, long-acting growth hormone, somapacitan, treatment, and management. The discussion of treatment aspects utilizing somapacitan was based on evidence from previous clinical studies and personal experience.

RESULTS

Clinical trial data demonstrated that somapacitan, a once-weekly reversible albumin-binding GH derivative, decreased truncal fat, improved visceral fat and lean body mass, increased insulin-like growth factor-I standard deviation score and exerted neutral effects on glucose metabolism. Overall, somapacitan was well-tolerated, adverse event rates were comparable with daily GH, antisomapacitan or anti-GH antibodies were not detected, and treatment satisfaction was in favor of somapacitan vs daily GH.

CONCLUSION

Somapacitan is an efficacious, safe, convenient and well-tolerated once-weekly long-acting GH formulation that reduces the treatment burden of once-daily GH injections for adults with GHD. This article provides a review of the pharmacology of somapacitan and offers practical recommendations based on previous clinical trial data on how to initiate, dose titration, monitoring and dose adjustments whilst on therapy in adults with GHD. Timing of measurement of serum insulin-like growth factor-I levels, information on administration, recommendations on missed doses, and clinical recommendations on dosing in certain sub-population of patients are also discussed.

Investigating the Bioavailability and Insulin-like Growth Factor-I Release of Two Different Strengths of Somapacitan: A Randomised, Double-Blind Crossover Trial

STUDY DESIGN AND OBJECTIVE

Randomised, double-blind, crossover trial to confirm bioequivalence of somapacitan, a long-acting growth hormone (GH), in 5 mg/1.5 mL and 10 mg/1.5 mL strengths in equimolar doses.

METHODS

Healthy participants were randomised (1:1:1) to subcutaneous somapacitan treatment in one dosing period with 5 mg/1.5 mL and two periods with 10 mg/1.5 mL. Eligibility criteria included age 18-45 years and body mass index 18.5-24.9 kg/m2. Exclusion criteria included history of GH deficiency, previous GH treatment, weight > 100.0 kg and participation in any clinical trial of an investigational medicinal product within 45 days or five times the half-life of the previous investigational product before screening. Area under the curve from time 0 until last quantifiable observation (AUC0-t), maximum serum concentration (Cmax), time to Cmax and terminal half-life of somapacitan and safety were assessed.

RESULTS

In total, 33 participants were randomised. For AUC0-t, estimated treatment ratio (ETR) (5 mg/1.5 mL versus 10 mg/1.5 mL) was 0.95 (90% confidence interval [CI] 0.89-1.01). Point estimate and 90% CIs were within the acceptance range (0.80-1.25). For Cmax, ETR was 0.77 (90% CI 0.68-0.89). Point estimate and 90% CIs were outside the acceptance range (0.80-1.25). Mean insulin-like growth factor-I (IGF-I) and IGF-I standard deviation score concentration-time curves for each strength were almost identical. No new safety issues were identified.

CONCLUSIONS

Bioequivalence criterion for somapacitan 5 mg/1.5 mL and 10 mg/1.5 mL was met for AUC0-t but not for Cmax. The two strengths had equivalent IGF-I responses.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03905850 (3 April 2019).

Hypopituitarism

Partial or complete deficiency of anterior or posterior pituitary hormone production leads to central hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency, or arginine vasopressin deficiency depending on the hormones affected. Hypopituitarism is rare and likely to be underdiagnosed, with an unknown but rising incidence and prevalence. The most common cause is compressive growth or ablation of a pituitary or hypothalamic mass. Less common causes include genetic mutations, hypophysitis (especially in the context of cancer immunotherapy), infiltrative and infectious disease, and traumatic brain injury. Clinical features vary with timing of onset, cause, and number of pituitary axes disrupted. Diagnosis requires measurement of basal circulating hormone concentrations and confirmatory hormone stimulation testing as needed. Treatment is aimed at replacement of deficient hormones. Increased mortality might persist despite treatment, particularly in younger patients, females, and those with arginine vasopressin deficiency. Patients with complex diagnoses, pregnant patients, and adolescent pituitary-deficient patients transitioning to adulthood should ideally be managed at a pituitary tumour centre of excellence.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Developments in the Management of Growth Hormone Deficiency: Clinical Utility of Somapacitan

Growth hormone (GH) replacement therapy for growth hormone deficiency (GHD) in children and adults has for over 25 years, until recently, been administered as daily injections. This daily treatment regimen often incurs a burden to patients and caregivers, leading to high rates of non-adherence and, consequently, decreased treatment efficacy outcomes. To address this shortcoming, long-acting growth hormones (LAGHs) have been developed with the aim of reducing the burden of daily injections, thereby potentially improving treatment adherence and outcomes. Somapacitan (Sogroya®) (Novo Nordisk, Bagsværd, Denmark) is a LAGH currently approved for the treatment of adult and childhood GHD (AGHD and CGHD, respectively) in several countries. Other LAGHs, such as somatrogon (Ngenla®) (Pfizer, New York, United States) and lonapegsomatropin/TransCon GH (Skytrofa®) (Ascendis Pharma, Copenhagen, Denmark), are also currently approved and available for the treatment of CGHD in several countries. In this review, we will consider the method of protraction, pharmacokinetics (PK) and pharmacodynamics (PD), efficacy, and safety results of somapacitan in adult and pediatric trials and how these characteristics differ from those of the other aforementioned LAGHs. Additionally, the administration of somapacitan and timing of measurement of serum insulin-like growth factor-I (IGF-I) levels are summarized. Information on administration, advice on missed doses, and clinical guidelines are discussed, as well as identifying which patients are suitable for somapacitan therapy, and how to monitor and adjust dosing whilst on therapy.

Safety of long-term use of daily and long-acting growth hormone in growth hormone-deficient adults on cancer risk

Daily injections of recombinant human growth hormone (rhGH) have been used in clinical practice for almost four decades as a replacement therapy in adult patients with GH deficiency (GHD). Long-term adherence to daily injections of rhGH is a clinical concern that may result in reduced therapeutic efficacy, and long-acting GH (LAGH) formulations have been developed in an attempt of overcoming this problem. Long-term safety issues of rhGH are the other side of the coin that has been carefully monitored over the years, particularly related to the proliferative actions of GH that could increase the risk of tumor recurrence or induce the development of new benign and malignant tumors. In this review, we present what is currently known about the cancer risk in GHD adults treated with daily rhGH injections and we discuss the major concerns and responses needed from future surveillance studies regarding the safety of LAGH preparations.

Impact of long-acting growth hormone replacement therapy in adult growth hormone deficiency: Comparison between adolescent, adult, and elderly patients

The predominant features of the adult growth hormone deficiency (GHD) syndrome may vary between patients of different age and age of onset of GHD. Evidence from clinical trials and long-term observational studies has informed our ability to understand the unique considerations regarding risks and benefits of daily growth hormone replacement therapy (GHRT) and specific dosing and monitoring strategies for these patient subgroups. High rates of nonadherence with daily GHRT presents a challenge to achieving optimal treatment outcomes and long-acting growth hormone (LAGH) formulations have been developed with the promise of improving treatment adherence resulting in improved therapeutic outcomes. While existing data from short-term studies have demonstrated noninferiority of efficacy and safety of LAGH compared to daily GHRT, long-term studies are needed to assess the full spectrum of outcomes of interest and long-term safety considerations specific to patients in adolescence, adulthood and the elderly GHD population. Since each LAGH formulation has a unique pharmacodynamic and pharmacokinetic profile optimal dosing and monitoring strategies will need to be developed to allow for the provision of individualized patient treatment.

Comparing treatment with daily and long-acting growth hormone formulations in adults with growth hormone deficiency: Challenging issues, benefits, and risks

Daily administration of growth hormone (GH) treatment has been in clinical use for treatment for GH deficiency (GHD) in adults for more than 30 years. Numerous studies have demonstrated evidence that GH treatment improves body composition, cardiovascular risk factors and quality of life with few side effects. Less frequent GH injections are hypothesized to improve adherence and several long-acting GH (LAGH) formulations have been developed and a few have been approved and marketed. Different pharmacological modifications have been applied and the pharmacokinetics and pharmacodynamics of LAGH are different to each other and to those of daily injections and require different dosing and monitoring specific for each LAGH. Studies have shown improved adherence with LAGH, and short-term efficacy and side effects are comparable between daily GH injections and LAGHs. Long-term treatment with daily GH injections is effective and safe, while long-term studies for LAGHs are awaited. In this review challenges, benefits, and risks of treatment with daily and long-acting GH preparations will be compared.

Effective GH Replacement With Somapacitan in Children With GHD: REAL4 2-year Results and After Switch From Daily GH

CONTEXT

Somapacitan is a long-acting GH derivative for treatment of GH deficiency (GHD).

OBJECTIVE

Evaluate the efficacy and tolerability of somapacitan in children with GHD after 2 years of treatment and after the switch from daily GH.

DESIGN

A randomized, multinational, open-labelled, controlled parallel group phase 3 trial, comprising a 52-week main phase and 3-year safety extension (NCT03811535).

SETTING

Eighty-five sites across 20 countries.

PATIENTS

A total of 200 treatment-naïve prepubertal patients were randomized and exposed; 194 completed the 2-year period.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (0.034 mg/kg/d) during the first year, after which all patients received somapacitan 0.16 mg/kg/wk.

MAIN OUTCOME MEASURES

Height velocity (HV; cm/year) at week 104. Additional assessments included HV SD score (SDS), height SDS, IGF-I SDS, and observer-reported outcomes.

RESULTS

HV was sustained in both groups between 52 and 104 weeks. At week 104, mean (SD) for HV between weeks 52 and 104 was 8.4 (1.5) cm/year after continuous somapacitan treatment and 8.7 (1.8) cm/year after 1 year of somapacitan treatment following switch from daily GH. Secondary height-related endpoints also supported sustained growth. Mean IGF-I SDS during year 2 was similar between groups and within normal range (-2 to +2). Somapacitan was well tolerated, with no safety or tolerability issues identified. GH patient preference questionnaire results show that most patients and their caregivers (90%) who switched treatment at year 2 preferred once-weekly somapacitan over daily GH treatment.

CONCLUSIONS

Somapacitan in children with GHD showed sustained efficacy and tolerability for 2 years, and after switching from daily GH. Patients/caregivers switching from daily GH expressed a preference for somapacitan.

CLINICAL TRIAL REGISTRATION

NCT03811535.

Investigation of the metabolic and endocrinological differences between daily and weekly growth hormone replacement therapy, somapacitan, in patients with adult growth hormone deficiency: A real-world pilot study

In this real-world pilot study, we evaluated the metabolic and endocrinological effects in patients with adult growth hormone deficiency (AGHD) who switched from daily growth hormone (GH) replacement therapy to weekly GH replacement therapy using somapacitan. Eleven patients with AGHD, whose medical treatment aside from GH replacement therapy did not change, were enrolled. We investigated the metabolic and endocrinological parameters between at switching and 6 months after switching from daily GH formulation to somapacitan. The results showed that body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), fasting plasma glucose (FPG), and liver functions were significantly improved 6 months after switching compared to those at switching (each P < .05). Besides, the improvement in HOMA-IR was significantly associated with the period of daily GH replacement therapy before switching (P = .048), while age, sex, improvement in BMI or liver functions, presence of any hormonal deficiency, and the existence of any hormonal replacement therapy significantly associated (P > .05). In addition, switching to GH replacement therapy did not affect endocrinological parameters. In conclusion, this study might indicate that weekly GH replacement therapy with somapacitan could have more beneficial points than daily GH replacement therapy. Considering the cohort of this study was small, future studies with larger cohorts should be necessary to confirm the results of this study.

Weekly somapacitan had no adverse effects on glucose metabolism in adults with growth hormone deficiency

PURPOSE

The long-term effects of long-acting growth hormone (LAGH) analogues on glucose metabolism in adult growth hormone deficiency (AGHD) are not known. We investigated the impact of LAGH somapacitan, administered once-weekly, on glucose metabolism in patients with AGHD.

METHODS

In post hoc-defined analyses, we compared the effects of somapacitan with daily growth hormone (GH) and placebo on fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β) in patients with AGHD across a unique data set from three phase 3 randomized controlled trials (REAL 1, REAL 2 and REAL Japan).

RESULTS

No new cases of diabetes mellitus were reported with somapacitan. Among GH-naïve patients (n = 120 somapacitan, n = 119 daily GH), higher changes from baseline in FPG, HOMA-IR and fasting insulin levels were observed with daily GH versus somapacitan at 34 weeks, but not at 86 weeks. HbA1c and HOMA-β did not differ between groups at either timepoint. Among treatment-naïve patients, sex, age, fasting insulin, glucose tolerance status and body mass index did not influence changes in glucose metabolism. In previously treated patients (REAL 1 extension: n = 51 somapacitan, n = 52 daily GH; REAL 2: n = 61 and n = 31, respectively; REAL Japan: n = 46 and n = 16, respectively), the difference in changes from baseline were not statistically significant between somapacitan and daily GH for any glucose metabolism parameters.

CONCLUSIONS

Somapacitan, compared with daily GH, did not adversely affect glucose metabolism up to 86 weeks in a large cohort of treatment-naïve or previously treated patients with AGHD. Trial registrations (date of registration): NCT02229851 (2 September 2014), NCT02382939 (3 March 2015), NCT03075644 (7 March 2017).

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.

Dose-exposure-IGF-I response of once-weekly somapacitan in adults with GH deficiency

OBJECTIVE

Growth hormone (GH) replacement therapy in patients with adult growth hormone deficiency (AGHD) is individually titrated due to variable dose-responses among patients. The aim of this study was to provide clinical guidance on dosing and titration of the novel long-acting GH derivative somapacitan based on analyses of somapacitan dose-insulin-like growth factor I (IGF-I) responses in AGHD patients.

DESIGN

Analyses of dosing information, 4364 somapacitan concentration samples and 4880 IGF-I samples from 330 AGHD patients treated with somapacitan in three phase 3 trials.

METHODS

Pharmacokinetic/pharmacodynamic modelling was used to evaluate starting dose groups by age and oral oestrogen therapy, characterise the dose-IGF-I response in the overall AGHD population and patient subgroups, predict the IGF-I response to dose changes and simulate missed dosing.

RESULTS

The analyses supported the clinical recommendations of higher starting doses for younger patients and women on oral oestrogen replacement therapy. For patients switching from daily GH treatment, the mean maintenance dose ratio between somapacitan (mg/week) and somatropin (mg/day) was predicted to be 8.2 (observed interquartile range of 6.7-9.1). Simulations of IGF-I SDS profiles confirmed the appropriate time for IGF-I sampling to be 3-4 days after somapacitan dosing and supported somapacitan administration with up to 3 days delay in case of missed dosing. Subgroup analyses characterised the dose-exposure-IGF-I response in patient subgroups and indicated that dose requirements are mainly influenced by sex and oral oestrogen treatment.

CONCLUSIONS

This study extends the knowledge of the somapacitan dose-IGF-I response and provides information on clinical dosing of once-weekly somapacitan in patients with AGHD.

Effective GH Replacement With Once-weekly Somapacitan vs Daily GH in Children with GHD: 3-year Results From REAL 3

CONTEXT

Current GH therapy requires daily injections, which can be burdensome. Somapacitan is a long-acting GH derivative in development for treatment of GH deficiency (GHD).

OBJECTIVE

Evaluate the efficacy, safety, and tolerability of once-weekly somapacitan after 3 years of treatment.

DESIGN

A multicenter, randomized, controlled, phase 2 study comparing somapacitan and once-daily GH for 156 weeks (NCT02616562).

SETTING

Twenty-nine sites in 11 countries.

PATIENTS

Fifty-nine children with GHD randomized (1:1:1:1) and exposed to treatment. Fifty-three children completed the 3-year period.

INTERVENTIONS

Patients received somapacitan (0.04 [n = 14], 0.08 [n = 15], or 0.16 [n = 14] mg/kg/wk) or daily GH (n = 14) (0.034 mg/kg/d, equivalent to 0.238 mg/kg/wk) subcutaneously during the first year, after which all patients on somapacitan received 0.16 mg/kg/wk.

MAIN OUTCOME MEASURES

Height velocity (HV) at year 3; changes from baseline in height SD score (HSDS), HVSDS, and IGF-I SDS.

RESULTS

The estimated treatment difference (95% CI) in HV for somapacitan 0.16/0.16 mg/kg/wk vs daily GH at year 3 was 0.8 cm/y (-0.4 to 2.1). Change in HVSDS from baseline to year 3 was comparable between somapacitan 0.16/0.16 mg/kg/wk, the pooled somapacitan groups, and daily GH. A gradual increase in HSDS from baseline was observed for all groups. At year 3, mean HSDS was similar for the pooled somapacitan groups and daily GH. Change from baseline to year 3 in mean IGF-I SDS was similar across treatments.

CONCLUSIONS

Once-weekly somapacitan in children with GHD showed sustained efficacy over 3 years in all assessed height-based outcomes with similar safety and tolerability to daily GH. A plain language summary (1) is available for this study.

CLINICAL TRIAL INFORMATION

This study has been registered at ClinicalTrials.gov, number NCT02616562 (REAL 3).

Efficacy and safety of long-acting growth hormone in adult growth hormone deficiency: A systematic review and meta-analysis

BACKGROUND & AIMS

No meta-analysis has analysed efficacy and safety of long-acting growth hormone (GH) therapy in adult GH deficiency. We undertook this meta-analysis to address this gap in knowledge METHODS: Electronic databases were searched for RCTs involving adult GH deficiency patients receiving weekly long-acting GH as compared to daily GH/placebo controls. Primary outcome was to evaluate changes in body-composition parameters. Secondary outcomes were to evaluate alterations in glycaemia and adverse-events.

RESULTS

Data from 5 studies involving 648 patients were analysed (4 studies having daily GH as active controls; 1 study having placebo as passive controls). Over 24-34 weeks clinical use, patients receiving long-acting GH had comparable change in lean mass [MD-0.28 kg (95%CI: 0.94 - 0.38); P = 0.41; I² = 29% (low heterogeneity)] and fat mass [MD-0.10 kg (95%CI: 1.97-1.78); P = 0.92; I² = 77%(considerable heterogeneity)] as compared to daily GH injections. Long-acting GH use was associated with significantly lower visceral adipose tissue [MD-1.75 cm²(95%CI: 2.14 to -1.35); P < 0.01; I² = 0% (low heterogeneity)] and higher gynoid fat-mass [MD 0.14 kg(95%CI:0.02-0.26); P = 0.03] compared to daily GH injections. Total adverse events [Risk ratio (RR) 1.65 (95% CI: 0.83-3.29); P = 0.15; I² = 68%] and severe adverse events [RR 0.60 (95% CI: 0.30-1.19); P = 0.14; I² = 0%] were not significantly different in long-acting GH group compared to controls. Occurrence of headache, arthralgia, nasopharyngitis, new onset diabetes, anti-GH antibodies were comparable among groups. Long-acting GH users had significantly higher treatment adherence compared to controls [OR 4.80 (95%CI:3.58-6.02); P < 0.01; I² = 0%].

CONCLUSION

Long-acting GH has comparable beneficial impact on body composition parameters in adult GH deficiency, is well tolerated without any increased adverse events.

Structure identification of circulating metabolites from somapacitan, a long-acting growth hormone derivative, and pharmacokinetics after single and multiple subcutaneous dosing in rats

Somapacitan is a growth hormone derivative approved for once-weekly treatment of growth hormone deficiency in adults and currently in clinical development for once-weekly dosing in children. The purpose of this study was to obtain non-clinical data from rats to support the safety evaluation of the most abundant metabolites of somapacitan in humans. The aims were to identify somapacitan metabolites and their relative proportions in rat plasma, identify the structure of abundant metabolites and measure the systemic metabolite exposure at the no-observed-adverse-effect level in the rat. After a single dose of radiolabelled somapacitan and analysis by high-performance liquid chromatography with radiochemical detection, seven somapacitan-related metabolites were detected in plasma from male rats, of which six were seen in plasma from female rats. The three most abundant metabolites (M1, M2 and M3) were structurally identified from liquid chromatography and mass spectrometry data, and a fourth metabolite (P1) was characterised from its specific retention time (lacking retention to the stationary phase) in plasma analysis with reversed-phase liquid chromatography and radiochemical detection. The metabolites were products from proteolysis of the peptide backbone in somapacitan. A deamidation product of the M1 metabolite (M1B) was also identified. Following multiple, twice-weekly dosing for 4 weeks, somapacitan was the principal plasma component up to 36 h after dosing. After 36 h, metabolites M1+M1B were the most abundant plasma components. Pharmacokinetic models were developed for somapacitan and metabolite P1 and used for steady-state assessment in the rat. Comparison of our data generated from rats with data from the parallel human study demonstrated that the most abundant metabolites were present in rats at higher levels than in humans. This study has provided non-clinical safety data that contribute to an overall safety assessment of somapacitan.

Guidance for the treatment of adult growth hormone deficiency with somapacitan, a long-acting growth hormone preparation

Adult growth hormone deficiency (AGHD) is a rare endocrine disorder characterized by an abnormal body composition, metabolic abnormalities associated with increased cardiovascular diseases, bone loss, and impaired quality of life. Daily subcutaneous injections with recombinant growth hormone (GH) can alleviate the abnormalities associated with AGHD. Several long-acting GH (LAGH) preparations are currently in development that aim to reduce treatment burden for patients receiving daily GH injections. Somapacitan (Sogroya^®; Novo Nordisk, Denmark) is the first LAGH preparation that has been approved for treatment of AGHD in the United States, Europe, and Japan. The recent approval of somapacitan and anticipated approval of other LAGH molecules presents new questions for physicians planning to treat AGHD with LAGH in the future. Differences in the technologies used to prolong the half-life of recombinant GH are expected to result in variations in pharmacokinetic and pharmacodynamic profiles between preparations. Therefore, it is essential that physicians understand and consider such variations when treating patients with these novel GH replacement therapies. Here, we present a set of treatment recommendations that have been created to guide physicians initiating therapy with somapacitan in patients with AGHD who are eligible for GH replacement. Furthermore, we will review the published data that underlie these recommendations to explain the rationale for the treatment and monitoring advice provided.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2020

While the COVID-19 pandemic also affected the work of regulatory authorities, the US Food and Drug Administration approved a total of 53 new drugs in 2020, one of the highest numbers in the past decades. Most newly approved drugs related to oncology (34%) and neurology (15%). We discuss these new drugs by level of innovation they provide, i.e., first to treat a condition, first using a novel mechanisms of action, and "others." Six drugs were first in indication, 15 first using a novel mechanism of action, and 32 other. This includes many drugs for the treatment of orphan indications and some for the treatment of tropical diseases previously neglected for commercial reasons. Small molecules continue to dominate new drug approvals, followed by antibodies. Of note, newly approved drugs also included small-interfering RNAs and antisense oligonucleotides. These data show that the trend for declines in drug discovery and development has clearly been broken.

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.

Similar safety and efficacy in previously treated adults with growth hormone deficiency randomized to once-weekly somapacitan or daily growth hormone

OBJECTIVE

Somapacitan is a long-acting, reversible albumin-binding growth hormone (GH) derivative in development. This study aimed to evaluate the safety and efficacy of once-weekly somapacitan versus daily GH over 52 weeks in Japanese patients with adult growth hormone deficiency (AGHD).

DESIGN

Phase 3, multicentre, randomized, parallel-group, open-label, active-controlled trial (NCT03075644).

PATIENTS

Previously GH-treated Japanese patients with AGHD were randomized 3:1 to somapacitan (n = 46) or daily GH (n = 16) for 20 weeks' dose titration and 32 weeks' fixed-dose treatment.

MEASUREMENTS

Primary endpoint was the incidence of adverse events (AEs). Secondary endpoints included change from baseline to week 52 in visceral, subcutaneous and total adipose tissue (VAT, SAT and TAT).

RESULTS

Mean (SD) prescribed doses after titration were 1.780 (1.058) mg/week for somapacitan and 0.197 (0.083) mg/day for daily GH. Rate of AEs per 100 patient-years was similar between arms (somapacitan, 312.7; daily GH, 309.8). Four AEs in the somapacitan arm were serious; none were considered treatment-related. Mean insulin-like growth factor-I standard deviation score (IGF-I SDS) was maintained from baseline in both arms. No significant differences were observed between arms for change from baseline to week 52 in VAT, SAT or TAT (estimated difference, somapacitan - daily GH [95% CI]: -1.74 [-18.13; 14.66], -11.53 [-35.54; 12.48] and - 12.85 [-47.31; 21.62] cm² , respectively).

CONCLUSIONS

Treatment in both groups was well tolerated, with no unexpected safety findings. Impact on adipose tissue was similar to somapacitan and daily GH in patients with AGHD. A short visual summary of our work is available at https://bit.ly/3946YNF.