The not-so-good old days: working with pituitary growth hormone in North America, 1956 to 1985

Approach to the Patient: Safety of Growth Hormone Replacement in Children and Adolescents

The use of recombinant human growth hormone (rhGH) in children and adolescents has expanded since its initial approval to treat patients with severe GH deficiency (GHD) in 1985. rhGH is now approved to treat several conditions associated with poor growth and short stature. Recent studies have raised concerns that treatment during childhood may affect morbidity and mortality in adulthood, with specific controversies over cancer risk and cerebrovascular events. We will review 3 common referrals to a pediatric endocrinology clinic, followed by a summary of short- and long-term effects of rhGH beyond height outcomes. Methods to mitigate risk will be reviewed. Finally, this information will be applied to each clinical case, highlighting differences in counseling and clinical outcomes. rhGH therapy has been used for more than 3 decades. Data are largely reassuring, yet we still have much to learn about pharmaceutical approaches to growth in children and the lifelong effect of treatment.

Mice with gene alterations in the GH and IGF family

Much of our understanding of GH's action stems from animal models and the generation and characterization of genetically altered or modified mice. Manipulation of genes in the GH/IGF1 family in animals started in 1982 when the first GH transgenic mice were produced. Since then, multiple laboratories have altered mouse DNA to globally disrupt Gh, Ghr, and other genes upstream or downstream of GH or its receptor. The ability to stay current with the various genetically manipulated mouse lines within the realm of GH/IGF1 research has been daunting. As such, this review attempts to consolidate and summarize the literature related to the initial characterization of many of the known gene-manipulated mice relating to the actions of GH, PRL and IGF1. We have organized the mouse lines by modifications made to constituents of the GH/IGF1 family either upstream or downstream of GHR or to the GHR itself. Available data on the effect of altered gene expression on growth, GH/IGF1 levels, body composition, reproduction, diabetes, metabolism, cancer, and aging are summarized. For the ease of finding this information, key words are highlighted in bold throughout the main text for each mouse line and this information is summarized in Tables 1, 2, 3 and 4. Most importantly, the collective data derived from and reported for these mice have enhanced our understanding of GH action.

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.

Childhood growth hormone deficiency, a diagnosis in evolution: The intersection of growth hormone history and ethics

In 1958 the first recorded case of a patient treated with human growth hormone for growth hormone deficiency was published. Since that time, the source and availability of human growth hormone have changed. With the increased availability of growth hormone, there has been an uptrend in the level below which childhood growth hormone deficiency is diagnosed based on provocative GH stimulation testing. This increase is despite better specificity of growth hormone assays in addition to a lack of supportive evidence regarding appropriate normal values. With these trends the diagnosis of childhood growth hormone deficiency is evolving, and clinicians should be aware that this may have potential ethical implications.

Growth hormone - past, present and future

Growth hormone (GH) research and its clinical application for the treatment of growth disorders span more than a century. During the first half of the 20th century, clinical observations and anatomical and biochemical studies formed the basis of the understanding of the structure of GH and its various metabolic effects in animals. The following period (1958-1985), during which pituitary-derived human GH was used, generated a wealth of information on the regulation and physiological role of GH - in conjunction with insulin-like growth factors (IGFs) - and its use in children with GH deficiency (GHD). The following era (1985 to present) of molecular genetics, recombinant technology and the generation of genetically modified biological systems has expanded our understanding of the regulation and role of the GH-IGF axis. Today, recombinant human GH is used for the treatment of GHD and various conditions of non-GHD short stature and catabolic states; however, safety concerns still accompany this therapeutic approach. In the future, new therapeutics based on various components of the GH-IGF axis might be developed to further improve the treatment of such disorders. In this Review, we describe the history of GH research and clinical use with a particular focus on disorders in childhood.

[Biologics in Rhinology - Forthcoming Personalized Concepts: the Future Starts Today]

Sinunasale Erkrankungen zählen mit zu den häufigsten chronischen Erkrankungen und führen zu einer erheblichen Störung der Lebensqualität, ein komorbides Asthma ist häufig. Trotz leitliniengerechter Therapie ist anzunehmen, dass mind. 20% der Patienten ihre Erkrankungssymptome nicht adäquat kontrollieren können. Neben den etablierten chirurgischen und konservativen Therapieoptionen finden sich nun vielversprechende Therapieansätze, die bspw. mittels therapeutischer Antikörper mechanistisch gezielt in die Pathophysiologie der Erkrankungen eingreifen können. Die Auswahl der geeigneten Patienten durch geeignete Biomarker und die richtige Therapie zum richtigen Stadium der Erkrankung anbieten zu können, ist das Ziel stratifizierter Medizin und eine wichtige Perspektive für die HNO.Chronic diseases of the nose and the paranasal sinuses are most common, frequently associated with bronchial asthma, and result in substantial reduction of quality of life. Despite optimal treatment according to guidelines, approx. 20 % of the patients will report inadequate control of symptoms. Apart from well established surgical and conservative approaches in therapy new therapeutic antibodies are available that aim specifically pathophysiological targets. The optimal allocation of effective therapy for patients using appropriate biomarkers at the most suitable timepoint is the hallmark of stratified medicine and an important perspective in ENT.

Overview on biotherapeutic proteins: impact on bioanalysis

This article provides an overview of the information and factors relevant to designing bioanalytical strategies in support of in vivo nonclinical and clinical studies of protein therapeutics. The summarized information includes representative types of the therapeutic proteins, their key structural characteristics, the relationship between post-translational modifications and function, issues during purification and formulation, PK of therapeutic proteins and immunogenicity. The effect of each of those on bioanalysis strategy has been pointed out. The impacts of structural variant and ‘free’/‘bound’ forms on PK assessment have been discussed.

Growth hormone, enhancement and the pharmaceuticalisation of short stature

This paper takes the biological drug human Growth Hormone (hGH) as a case study to investigate processes of pharmaceuticalisation and medicalisation in configuring childhood short stature as a site for pharmaceutical intervention. Human growth hormone is considered to have legitimate applications in treating childhood growth hormone deficiency and short stature associated with other recognised conditions. It is also regarded by bioethicists and others as a form of human biomedical enhancement when applied to children with idiopathic or 'normal' short stature. The purpose of this study is not to evaluate whether treatment of idiopathic short stature is enhancement or not, but to evaluate how some applications of hGH in treating short stature have come to be accepted and stabilised as legitimate 'therapies' while others remain contested as 'enhancements'. A comparative, historical approach is employed, drawing on approaches from medical sociology and Science and Technology Studies (STS) to set out a socio-technical history of hGH in the US and UK. Through this history the relative influence and interplay of drivers of pharmaceuticalisation, including industry marketing and networks of drug distribution, and processes of medicalisation will be employed to address this question and simultaneously query the value of enhancement as a sociological concept.

Comparison between the growth response to growth hormone (GH) therapy in children with partial GH insensitivity or mild GH deficiency

OBJECTIVES

GH therapy is still controversial, except in severe GH deficiency (SGHD). The objective of this study was to compare the response to growth hormone (GH) therapy in children with partial GH insensitivity (PGHIS) and mild GH deficiency (MGHD) with those with SGHD.

SUBJECTS AND METHODS

Fifteen PGHIS, 11 MGHD, and 19 SGHD subjects, followed up for more than one year in the Brazilian public care service, were evaluated regarding anthropometric and laboratory data at the beginning of treatment, after one year (1st year) on treatment, and at the last assessment (up to ten years in SGHD, up to four years in MGHD, and up to eight years in PGHIS).

RESULTS

Initial height standard deviation score (SDS) in SGHD was lower than in MGHD and PGHIS. Although the increase in 1 st year height SDS in comparison to initial height SDS was not different among the groups, height-SDS after the first year of treatment remained lower in SGHD than in MGHD. There was no difference in height-SDS at the last assessment of the children among the three groups. GH therapy, in the entire period of observation, caused a trend towards lower increase in height SDS in PGHIS than SGHD but similar increases were observed in MGHD and SGHD.

CONCLUSION

GH therapy increases height in PGHIS and produces similar height effects in MGHD and SGHD.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.

History of growth hormone therapy

Although the importance of the pituitary gland for growth was recognized in late 19(th) century, Growth hormone (GH) therapy was made available for severely GH-deficient children and adolescents only in late 1950s. Use of GH for other conditions was limited because of the limited supply of human pituitary-derived hormone. With unlimited availability of recombinant human GH (rhGH), the scenario of GH treatment has been changed enormously. Currently there is ever increasing list of indications of GH treatment in children, adolescents, and adults.

Emerging options in growth hormone therapy: an update

Growth hormone (GH) was first used to treat a patient in 1958. For the next 25 years it was available only from cadaver sources, which was of concern because of safety considerations and short supply. In 1985, GH produced by recombinant DNA techniques became available, expanding its possible uses. Since that time there have been three indications approved by the US Food and Drug Administration (FDA) for GH-deficiency states and nine indications approved for non-GH-deficiency states. In 2003 the FDA approved GH for use in idiopathic short stature (ISS), which may indirectly cover other diagnoses that have short stature as a feature. However, coverage for GH therapy is usually more reliably obtainable for a specific indication, rather than the ISS indication. Possible future uses for GH therapy could include the treatment of syndromes such as Russell-Silver syndrome or chondrodystrophy. Other non-short-stature indications could include wound healing and burns. Other uses that have been poorly studied include aging and physical performance, in spite of the interest already shown by elite athletes in using GH. The safety profile of GH developed over the past 25 years has shown it to be a very safe hormone with few adverse events associated with it. The challenge for the future is to follow these patients into adulthood to determine whether GH therapy poses any long-term risks.

Managing idiopathic short stature: role of somatropin (rDNA origin) for injection

Idiopathic short stature (ISS) is a term that describes short stature in children who do not have growth hormone (GH) deficiency and in whom the etiology of the short stature is not identified. Between 1985 and 2000, more than 40 studies were published regarding GH therapy for ISS. Only 12 of these had data to adult height, of which only 4 were controlled studies. A subsequent placebo-controlled study that followed subjects to adult height indicated that there was a gain of 3.7–7.5 cm in height with GH treatment. In 2003, the US Federal Drug Administration (FDA) approved GH for treatment of short stature. Even before FDA approval, patients with ISS made up about 20% of patients in GH databases, which is largely unchanged since FDA approval. There remains some controversy as to whether GH should be used to treat ISS. This controversy centers on the fact that there has been no definitive demonstration that short stature results in a disadvantage or problems with psychological adjustment, and thus, no demonstration that GH therapy results in improvement in quality of life.

Somatotropin in the treatment of growth hormone deficiency and Turner syndrome in pediatric patients: a review

Growth hormone (GH), also known as somatotropin, is a peptide hormone that is synthesized and secreted by the somatotrophs of the anterior pituitary gland. The main action of GH is to stimulate linear growth in children; however, it also fosters a healthy body composition by increasing muscle and reducing fat mass, maintains normal blood glucose levels, and promotes a favorable lipid profile. This article provides an overview of the normal pathophysiology of GH production and action. We discuss the history of GH therapy and the development of the current formulation of recombinant human GH given as daily subcutaneous injections. This paper reviews two of the longest standing FDA-approved indications for GH treatment, GH deficiency and Turner syndrome. We will highlight the pathogenesis of these disorders, including presentations, presumed mechanism(s) for the associated short stature, and diagnostic criteria, with a review of stimulation test benefits and pitfalls. This review also includes current recommendations for GH therapy to help maximize final height in these children, as well as data demonstrating the efficacy and safety of GH treatment in these populations.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.

New preparations comprising recombinant human growth hormone: deliberations on the issue of biosimilars

Manufactured recombinant human GH (rhGH) has been available for more than 25 years. In the meantime, the GH produced by various manufacturers has been approved for application in replacement therapy in children and adults with GH deficiency or a number of disorders involving small stature in children. Until recently approval for each individual diagnosis was only granted after extensive studies on the long-term efficacy (e.g. adult height reached) and safety of the various products. Meanwhile, the European approving agency, the European Medicines Evaluation Agency (EMEA), has relinquished this restrictive stance. Thus, new rhGH preparations can count on gaining approval for existing indications even without conducting standard clinical studies of their efficacy and safety for each of these indications. The EMEA's reconsideration is apparently based on the rationale that recombinant GH can, in effect, be considered equivalent to the tried and tested preparations in wide use, provided certain specifications are met. The term 'biosimilars' was coined to denote the similarities between the products rather than their parity, as is the case with generics for instance. The higher complexity of biopharmaceuticals relates not only to the substances themselves but also to the manufacturing process. It is generally believed that modifications to a manufacturing process - which are a prerequisite for a patent - may cause modifications of the active substance which then may lead to different long-term effects. Thus, the term 'biosimilar' does not indicate that complex biopharmaceuticals deriving from the same substance are entirely identical, nor does the approval of a 'biosimilar' ensure this. The factual information provided here is offered towards clarification of some uncertainties and as a contribution towards resolving open questions relating to the topic of biosimilars. The final choice of product to be prescribed must be made by the informed, independent physician.

Brief review and commentary: diagnosis of pediatric pituitary disorders

Pediatric pituitary diagnosis is complicated by the unique developmental characteristics, secretory patterns and regulation of each pituitary hormone system. Although dynamic test procedures have been described, validation of each procedure is limited and universally agreed diagnostic criteria are not available. Clinical acumen, experience and judgment continue to be primary elements of pituitary diagnosis.

Birth size and neonatal levels of major components of the IGF system: implications for later risk of cancer

Pre- and perinatal conditions and processes may affect the risk for some forms of cancer in later life, while the insulin-like growth factor (IGF) system may play a role in both early somatic growth and later carcinogenesis. Birth weight and length, and the variation of major components of the IGF system immediately after birth, were analyzed in relation to selected physiological and pathological variables. The study comprised 331 healthy full-term newborns from whom blood samples were taken during routine phlebotomy no later than the fifth day of life. Measurements of IGF-I, IGF-II and IGF-binding protein-3 concentrations were performed. Birth length and weight were measured and information on socio-economic and medical variables was recorded. The concentrations of all three proteins were lower when blood bilirubin levels were high, possibly as a result of compromised liver function and/or as a component of an activated acute phase reaction. Birth weight was significantly higher by about 46 g among children whose IGF-I was higher by one SD, while the associations of birth weight and length with other components of the IGF system were in the predicted directions, albeit only in trend. We conclude that in early life, growth is related to the IGF system, mostly IGF-I. The latter is lower in children with jaundice, possibly because of hepatic dysfunction and/or as part of an acute phase reaction. We speculate that elevations of IGF-I in early life might explain the increased risk of cancer in individuals born with a higher birth weight.