Linear growth of children with X-linked hypophosphatemia treated with burosumab: a real-life observational study.

To assess the long-term efficacy of burosumab for pediatric patients with X-linked hypophosphatemia, focusing on linear growth. This multi-center retrospective study included 35 pediatric patients who began treatment with burosumab between January 2018 and January 2021. We collected clinical data, anthropometric measurements, laboratory results, and Rickets Severity Score (RSS), from 2 years prior to treatment initiation and up to 4 years after. Burosumab was initiated at a mean age of 7.5 ± 4.4 years (range 0.6-15.9), with a mean initial dose of 0.8 ± 0.3 mg/kg, which was subsequently increased to 1.1 ± 0.4 mg/kg. The patients were followed for 2.9 ± 1.4 years (range 1-4) after initiating burosumab. Serum phosphorus levels increased from 2.7 ± 0.8 mg/dl at burosumab initiation to 3.4 ± 0.6 mg/dl after 3 months and remained stable (p < 0.001). Total reabsorption of phosphorus increased from 82.0 ± 6.8 to 90.1 ± 5.3% after 12 months of treatment (p = 0.041). The RSS improved from 1.7 ± 1.0 at burosumab initiation to 0.5 ± 0.6 and 0.3 ± 0.6 after 12 and 24 months, respectively (p < 0.001). Both height z-score and weight z-score improved from burosumab initiation to the end of the study: from - 2.07 ± 1.05 to - 1.72 ± 1.04 (p < 0.001) and from - 0.51 ± 1.12 to - 0.11 ± 1.29 (p < 0.001), respectively. Eight children received growth hormone combined with burosumab treatment. Height z-score improved among those who received growth hormone (from - 2.33 ± 1.12 to - 1.94 ± 1.24, p = 0.042) and among those who did not (from - 2.01 ± 1.01 to - 1.66 ± 1.01, p = 0.001). CONCLUSION:  Burosumab treatment in a real-life setting improved phosphate homeostasis and rickets severity and enhanced linear growth. WHAT IS KNOWN: • Compared to conventional therapy, burosumab treatment has been shown to increase serum phosphate levels and reduce the severity of rickets. • The effect of burosumab on growth is still being study. WHAT IS NEW: • Height z-score improved between the start of burosumab treatment and the end of the study (-2.07 ± 1.05 vs. -1.72 ± 1.04, p < 0.001). • Eight children received burosumab combined with growth hormone treatment without side effects during the concomitant treatments.

An open-label extension of a phase 2 dose-finding study of once-weekly somatrogon vs. once-daily Genotropin in children with short stature due to growth hormone deficiency: results following 5 years of treatment.

OBJECTIVES: Somatrogon is a long-acting recombinant human growth hormone (GH) employed as a once-weekly treatment for children with GH deficiency (GHD). A 12-month, phase 2 study of once-weekly somatrogon vs. once-daily GH (Genotropin®) was initiated, after which participants could enroll into an open-label extension (OLE) evaluating the safety and efficacy of long-term somatrogon treatment. METHODS: There were five study periods, Periods I and II were 6 months each while Periods III, IV, and V were 12 months each. In the main study (Periods I and II), 53 prepubertal children with GHD were randomized to once-weekly somatrogon (0.25, 0.48, or 0.66 mg/kg/week) or once-daily Genotropin (0.034 mg/kg/day); 48 continued into the OLE, consisting of Period III (original somatrogon dose; Genotropin recipients randomized to one of three somatrogon doses), Period IV (somatrogon 0.66 mg/kg/week), and Period V (prefilled somatrogon pen [0.66 mg/kg/week]). RESULTS: At the end of Period III, the mean ± SD annual height velocity (HV) for 0.25, 0.48, and 0.66 mg/kg/week somatrogon groups was 7.73 ± 1.89, 7.54 ± 1.28, and 8.81 ± 1.12 cm/year, respectively; HV was sustained during Periods IV/V. Height SD scores (SDS) showed progressive improvement throughout the OLE, regardless of initial cohort assignment, approaching the normal range (-0.69 ± SD 0.87) at the end of Period V Year 1. Mild or moderate treatment-emergent adverse events were reported in 81.3% of participants, most unrelated to study drug. CONCLUSIONS: Up to 5 years of once-weekly somatrogon was well tolerated and resulted in sustained improvement in height SDS and delta height SDS in prepubertal short children with GHD.

Long-Acting C-Terminal Peptide-Modified hGH (MOD-4023): Results of a Safety and Dose-Finding Study in GHD Children.

Context: Daily injections are required for growth hormone (GH) replacement therapy, which may cause low compliance as a result of inconvenience and distress in patients. Objective: C-terminal peptide-modified human GH (MOD-4023) is developed for once-a-week dosing regimen in GH-deficient (GHD) adults and children. The present trial was a safety and dose-finding study for weekly MOD-4023 in GHD children. Design: A multicenter, open-label, randomized, controlled phase 2 study in children with GHD, evaluating the safety, tolerability, pharmacokinetics/pharmacodynamics, and efficacy of three different weekly MOD-4023 doses, compared with daily recombinant human GH (r-hGH). Setting: The trial was conducted in 14 endocrinology centers in Europe. Patients: Fifty-three prepubertal children with GHD completed 12 months of treatment with either MOD-4023 (N = 42) or r-hGH (N = 11). Interventions: C-terminal peptide-modified hGH (MOD-4023) was administered weekly at a dose of either 0.25, 0.48, or 0.66 mg/kg/wk and compared with daily hGH at a dose of 0.24 mg/kg/wk. Results: MOD-4023 showed an estimated half-life approximately fivefold to 10-fold longer when compared with daily r-hGH. Insulin-like growth factor (IGF)-I and IGF-binding peptide 3 showed a dose-dependent increase during MOD-4023 treatment. IGF-I standard deviation score for MOD-4023 did not exceed +2. All MOD-4023 cohorts demonstrated adequate catch-up growth. The 0.66 mg/kg/wk dose demonstrated efficacy closest to daily r-hGH. No serious adverse events were observed during MOD-4023 treatment, and its tolerability was consistent with known properties of r-hGH. Conclusions: This study confirms the long-acting properties of MOD-4023 and shows a promising safety and tolerability profile. This provides support for initiation of a phase 3 study in GHD children using a single weekly injection of MOD-4023.

Mortality and cancer incidence among patients treated with recombinant growth hormone during childhood in Israel.

CONTEXT: The inconclusive evidence regarding long-term safety of recombinant human growth hormone (rhGH) therapy underlines the need for long-term large-scale cohorts. OBJECTIVE: To assess long-term mortality and cancer incidence among patients treated with rhGH during childhood in Israel. DESIGN: A population-based cohort study. SETTING: Data were retrieved from a national register established in 1988. Mortality data from the national population register were available through 31 December 2014. Data on cancer incidence from the national cancer registry were available through 31 December 2012. PARTICIPANTS: All patients ≤19 years approved for rhGH treatment during 1988-2009 were included. Patients were assigned to three risk categories, according to the underlying condition leading to growth disorder. MAIN OUTCOME MEASURES: All-cause mortality and cancer incidence rates were calculated, based on person-years at risk. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were calculated, using the Israeli general population as a reference. RESULTS: Included were 1687 patients assigned to the low-risk category and 440 patients assigned to the intermediate-risk category. In the low-risk category, all-cause mortality and cancer incidence were not significantly different than expected (SMR 0·81, 95% CI 0·22-2·08 and SIR 0·76, 95% CI 0·09-2·73). In the intermediate-risk category, all-cause mortality and cancer incidence were significantly higher than expected (SMR 4·05, 95% CI 1·62-8·34 and SIR 4·52, 95% CI 1·22-11·57). CONCLUSIONS: No increased risk of mortality or cancer incidence was found in low-risk patients treated with rhGH during childhood. Patients with prior risk factors were at higher risk of both mortality and cancer.

Monitoring gonadotropin-releasing hormone analogue (GnRHa) treatment in girls with central precocious puberty: a comparison of four methods.

AIM: The objective of this study was to validate basal, post-gonadotropin-releasing hormone analogue (post-GnRHa) and first-voided urinary LH (ULH) as alternatives to an LHRH stimulation test in monitoring treatment efficacy in central precocious puberty (CPP). METHODS: Seventeen girls with CPP were followed over 22.5±9.1 months during GnRHa (triptorelin) treatment. ULH and post-GnRHa LH levels were obtained every 4 months before and 24 h after GnRHa administration, respectively, along with clinical and bone age (BA) evaluation. LHRH stimulation tests were performed annually. RESULTS: A total of 36 LHRH stimulation tests demonstrated adequate suppression with a peak LH of 0.57±0.33 IU/L. The corresponding basal LH was 0.27±0.16 IU/L. Ninety post-GnRHa LH measurements were similar to LHRH-stimulated LH levels (0.56±0.31 IU/L), whereas 8% of ULH levels were above prepubertal threshold. Fourteen episodes of growth acceleration and ten episodes of BA advancement resolved without treatment modification. CONCLUSION: Suppressed basal and post-GnRHa LH levels indicate adequate suppression of puberty. Clinical breakthroughs during treatment are transient and resolved spontaneously.

The diagnostic value of first-voided urinary LH compared with GNRH-stimulated gonadotropins in differentiating slowly progressive from rapidly progressive precocious puberty in girls.

OBJECTIVE: Characterization of pubertal progression is required to prevent unnecessary intervention in unsustained or slowly progressive (SP) precocious puberty (PP), while delivering hormonal suppression in rapidly progressive (RP) PP. We aimed to assess the diagnostic value of first-voided urinary LH (ULH) compared with GNRH-stimulated gonadotropins in differentiating these forms of PP. METHODS: A total of 62 girls with PP underwent both GNRH stimulation and ULH assay. Fifteen girls with peak LH ≥ 10 IU/L started treatment immediately, whereas the other 47 girls were evaluated after 6 months for pubertal advancement, height acceleration, and bone-age maturation. Based on these criteria, the participants were assigned to five subgroups: pubertal regression, no progression or progression by one, two or three criteria. The first three subgroups were defined as SP-PP (n=29), while the other two subgroups were defined as RP-PP (n=18). An additional 23 prepubertal girls were evaluated for ULH. RESULTS: ULH but not serum gonadotropins could distinguish girls with two and three criteria from less progressive subgroups. By comparison with SP-PP (i.e. regression group and groups 0 and 1), those with RP-PP (group 2+3) had lower peak FSH (9.28±2.51 vs 12.57±4.30; P=0.007) and higher peak LH:FSH ratio (0.42±0.30 vs 0.22±0.12; P=0.022) and ULH (1.63±0.65 vs 1.05±0.26 IU/l; P<0.001). Based on receiver operating characteristics analysis, a ULH cutoff of 1.16 IU/l had a better sensitivity (83%) and positive and negative predictive values (65 and 88% respectively) than the other two parameters, with a specificity of 72%. CONCLUSIONS: ULH assay is a noninvasive, reliable method that can assist in the distinction between SP- and RP-PP.

Training reduces catabolic and inflammatory response to a single practice in female volleyball players.

We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Thirteen female, national team level, Israeli volleyball players (age 16.0 ± 1.4 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60 minutes of volleyball practice, before and after 7 weeks of training during the initial phase of the season. Training involved tactic and technical drills (20% of time), power and speed drills (25% of time), interval sessions (25% of time), endurance-type training (15% of time), and resistance training (15% of time). To achieve greater training responses, the study was performed during the early phase (first 7 weeks) of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor-I (IGF-I) and IGF-binding protein-3, the catabolic hormone cortisol, the proinflammatory marker interleukin-6 (IL-6), and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of vertical jump, anaerobic properties (peak and mean power by the Wingate Anaerobic Test), and predicted VO2max (by the 20-m shuttle run). Volleyball practice, both before and after the training intervention, was associated with a significant increase of serum lactate, GH, and IL-6. Training resulted in a significantly reduced cortisol response ([INCREMENT]cortisol: 4.2 ± 13.7 vs. -4.4 ± 12.3 ng · ml, before and after training, respectively; p < 0.02), and IL-6 response ([INCREMENT]IL-6: 1.3 ± 1.0 vs. 0.3 ± 0.4 pg · ml, before and after training, respectively; p < 0.01) to the same relative intensity volleyball practice. The results suggest that along with the improvement of power and anaerobic and aerobic characteristics, training reduces the catabolic and inflammatory response to exercise.

Training increases anabolic response and reduces inflammatory response to a single practice in elite male adolescent volleyball players.

We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Fourteen male, elite, national team-level, Israeli volleyball players (age, 16.3±1.1 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60-min volleyball practice, before and after 7 weeks of training during the initial phases of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, and testosterone; the catabolic hormone cortisol; the pro-inflammatory markers interleukin (IL) 6, and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of both anaerobic and aerobic properties. Before the training intervention, the typical volleyball practice was associated with a significant increase of GH and testosterone and also with a significant increase of IL-6. Training resulted in a significantly greater GH response (ΔGH, 2.5±2.4 vs. 4.7±3.0 ng/mL, before and after training, respectively; p<0.02) and reduced IL-6 response (ΔIL-6, 2.0±1.6 vs. 0.6±0.7 pg/mL, before and after training, respectively; p<0.01) to the same relative intensity volleyball practice. The results suggest that, along with the improvement of anaerobic and aerobic characteristics, training leads to a greater anabolic and reduced inflammatory response to exercise.