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Short stature remains the most common reason for referral to a pediatric Endocrinologist and its management remains a challenge. One of the main controversies is the diagnosis of idiopathic short stature and the role of new technologies for genetic investigation of children with inadequate growth. Complexities in management of children with short stature includes selection of who should receive interventions such as recombinant human growth hormone, and how should this agent dose be adjusted during treatment. Should anthropometrical data be the primary determinant or should biochemical and genetic data be used to improve growth response and safety? Furthermore, what is considered a suboptimal response to growth hormone therapy and how should this be managed? Treatment of children with short stature remains a "hot" topic and more data is needed in several areas. These issues are reviewed in this paper.

Growth hormone (GH) is used to treat short stature and growth failure associated with growth disorders. Birth size and GH status variably modulate response to GH therapy. The aim of this study was to determine the effect of birth size on response to GH therapy, and to determine the impact of GH status in patients born small for gestational age (SGA) on response to GH therapy. Data from the prospective, non-interventional American Norditropin® Studies: Web-Enabled Research (ANSWER) Program were analyzed for several growth outcomes in response to GH therapy over 3 years. GH-naïve children from the ANSWER Program were included in this analysis: SGA with peak GH ≥10 ng/mL (20 mIU/l), SGA with peak GH <10 ng/mL (20 mIU/l), isolated growth hormone deficiency (IGHD) born SGA, IGHD not born SGA, and idiopathic short stature. For patients with IGHD, those who did not meet criteria for SGA at birth showed greater improvements in height SDS and BMI SDS than patients with IGHD who met criteria for SGA at birth. For patients born SGA, response to GH therapy varied with GH status. Therefore, unlike previous guidelines, we recommend that GH status be established in patients born SGA to optimize GH therapy.

Recombinant human growth hormone (rhGH) has been in clinical use for more than 30 years. With the expiration of patent exclusivity for the first wave of rhGH products and other biopharmaceuticals, the opportunity emerged for the development of biosimilar medicines. A biosimilar is defined by the European Medicines Agency (EMA) as a biological medicine that is similar to another biological medicine that has already been authorized for use. The EMA led the way (well ahead of the Food and Drug Administration in the US) in developing the biosimilar concept, and the type of science-based regulatory framework required to ensure high-quality, safe, and effective biosimilar medicines; the provisions for approval of biosimilars have been in place in Europe since 2005. Under these provisions, Omnitrope^® was approved by the EMA in 2006 as the world's first biosimilar medicine; 2016 therefore marks the 10th anniversary of its approval in Europe. A substantial data set, based on clinical development studies and 10 years of postapproval use, has now accumulated for biosimilar rhGH; this data set shows that the product is an effective treatment option for children who require rhGH treatment, and has a safety profile that is consistent with the rhGH class. The decade since the EMA approved biosimilar rhGH has seen the successful approval and clinical use of 20 biosimilar medicines, confirming the integrity of the scientific basis for the biosimilar concept, as well as the quality of regulatory decision-making.

After the introduction of recombinant human growth hormone (rhGH) in 1985, a myriad of children and adults have benefited from its growth-promoting and metabolic effects. Nowadays, current therapeutic regimens rely on daily subcutaneous GH injections that could be burdensome and inconvenient to pediatric patients. As expected with any long-term parenteral pharmacological treatment, these daily regimens may promote nonadherence, poor compliance, treatment abandonment and/or suboptimal clinical outcomes. In order to improve patient and caregiver acceptance of proposed regimens, simplified dosing schedules could potentially aid in reducing poor compliance and maximize the therapeutic end results. Long-acting GH formulations have been designed and perfected over the last two decades, and currently there are several formulations in advanced stages of research as a reasonable attempt to improve patient's adherence to GH treatment. A long-acting GH preparation allowing for reduced injection frequency is likely to improve treatment adherence and to decrease the distress and inconvenience associated with daily injections. This review presents an update about the status of current and recent efforts that have enabled the formulation of sustained-release, long-acting rhGH as it has been longed for many years in the pediatric endocrinology field.

OBJECTIVE:The Growth Hormone (GH) Research Society (GRS) convened a workshop to address important issues regarding trial design, efficacy, and safety of long-acting growth hormone preparations (LAGH). PARTICIPANTS/METHODS:A closed meeting of 55 international scientists with expertise in GH, including pediatric and adult endocrinologists, basic scientists, regulatory scientists, and participants from the pharmaceutical industry. EVIDENCE/METHODS:Current literature was reviewed for gaps in knowledge. Expert opinion was used to suggest studies required to address potential safety and efficacy issues. CONSENSUS PROCESS/METHODS:Following plenary presentations summarizing the literature, breakout groups discussed questions framed by the planning committee. Attendees reconvened after each breakout session to share group reports. A writing team compiled the breakout session reports into a draft document that was discussed and revised in an open forum on the concluding day. This was edited further and then circulated to attendees from academic institutions for review after the meeting. Participants from pharmaceutical companies did not participate in the planning, writing, or in the discussions and text revision on the final day of the workshop. Scientists from industry and regulatory agencies reviewed the manuscript to identify any factual errors. CONCLUSIONS:LAGH compounds may represent an advance over daily GH injections because of increased convenience and differing phamacodynamic properties, providing the potential for improved adherence and outcomes. Better methods to assess adherence must be developed and validated. Long-term surveillance registries that include assessment of efficacy, cost-benefit, disease burden, quality of life, and safety are essential for understanding the impact of sustained exposure to LAGH preparations.

CONTEXT/BACKGROUND:Iodide (I(-)), an essential constituent of the thyroid hormones, is actively accumulated in the thyroid by the Na(+)/I(-) symporter (NIS), a key plasma membrane protein encoded by the slc5a5 gene. Mutations in slc5a5 cause I(-) transport defects (ITDs), autosomal-recessive disorders in which I(-) accumulation is totally or partially impaired, leading to congenital hypothyroidism. The characterization of NIS mutants has yielded significant insights into the molecular mechanism of NIS. OBJECTIVE:This study aimed to determine the basis of a patient's ITD clinical phenotype, by sequencing her slc5a5 gene. DESIGN/METHODS:Genomic DNA was purified and the slc5a5 gene sequence determined. Functional in vitro studies were performed to characterize the V270E NIS mutant. PATIENT/METHODS:The index patient was diagnosed with hypothyroidism with minimal radioiodide uptake in a normally located, although enlarged, thyroid gland. RESULTS:We identified a new NIS mutation: V270E. The patient had the compound heterozygous NIS mutation R124H/V270E. R124H NIS has been characterized previously. We show that V270E markedly reduces I(-) uptake via a pronounced (but not total) impairment of the protein's plasma membrane targeting. Remarkably, V270E is intrinsically active. Therefore, a negative charge at position 270 interferes with NIS cell surface trafficking. The patient's minimal I(-) uptake enabled sufficient thyroid hormone biosynthesis to prevent cognitive impairment. CONCLUSIONS:A nonpolar residue at position 270, which all members of the SLC5A family have, is required for NIS plasma membrane targeting.

BACKGROUND:Sustained-release GH formulations may provide a strategy for improving treatment compliance and persistence in GH-deficient patients. OBJECTIVE:The aim of the study was to examine efficacy and safety of LB03002, a sustained-release GH formulation for once-weekly administration. DESIGN/METHODS:We conducted a phase III, 12-month, multinational, randomized, open-label, comparator-controlled trial with a 12-month uncontrolled extension. PATIENTS/METHODS:Prepubertal GH treatment-naive GH-deficient children (mean age, 7.8 y) participated in the study. INTERVENTION/METHODS:We administered once-weekly LB03002 (n=91) or daily GH (n=87) for 1 year, followed by once-weekly LB03002 for all patients for another year (LB03002 throughout, n=87; switched to LB03002, n=80). OUTCOME MEASURES/METHODS:Height, height velocity (HV), IGF-1, GH antibodies, and adverse events were determined throughout. Primary analysis was noninferiority of LB03002 vs daily GH at 1 year by analysis of covariance. RESULTS:Mean±SD HV during year 1 was 11.63±2.60 cm/y with LB03002, and 11.97±3.09 cm/y with daily GH, with increases from baseline of 8.94±2.91 and 9.04±3.19 cm/y, respectively. The least square mean HV difference for LB03002 - daily GH was -0.43 cm/y (99% confidence interval, -1.45 to 0.60 cm/y). Mean HV also remained above baseline in year 2 (8.33±1.92 cm/y in the LB03002 throughout group, and 7.28±2.34 cm/y in the switched to LB03002 group). Injection site reactions occurred more frequently in LB03002-treated patients but were considered mild to moderate in >90% of cases. CONCLUSIONS:Growth response with once-weekly LB03002 in GH-deficient children is comparable to that with daily GH, achieving expected growth rates for 24 months. Once-weekly LB03002 is a strong candidate for long-term GH replacement in GH-deficient children.

BACKGROUND:Silver-Russell syndrome (SRS) is an imprinting defect disease. This is the first study of Chinese children with SRS caused by chromosome 11p15 imprinting defects. METHODS:Twenty-five SRS cases, diagnosed in Beijing Children's Hospital from 2006 to 2012, were studied retrospectively to detect chromosome 11p15 imprinting defects. RESULTS:Over 80% of the children had (i) small for gestational age and postnatal growth retardation (mean height standard deviation score [HT SDS] was -3.56), (ii) mean body mass index (BMI) SDS was -2.10, and (iii) skeletal malformation. Chromosome 11p15 imprinting defects were examined in 16 of the 25 patients. Six had hypomethylation in chromosome 11p15 imprinting control region 1 (ICR1) of the paternal allele; one had hypomethylation in chromosome 11p15 ICR1 and hypermethylation in imprinting control region 2 (ICR2). Another patient had a duplicated maternal chromosome 11p15 fragment. Six patients had been treated with for 3-24 months. Growth rates ranged from 4 to 10.8 cm/year. CONCLUSIONS:This study demonstrated that Chinese children with SRS had more growth retardation than bone retardation, severely low levels of BMI, triangular faces, and limb asymmetry. Chromosome 11p15 imprinting defects contributed to 50% of these cases, and ICR1 hypomethylation was associated with asymmetry.