Dose-dependent catch-up growth after 2 years of growth hormone treatment in intrauterine growth-retarded children. Belgian and French Pediatric Clinics and Sanofi-Choay (France)

Favorable Growth Hormone Treatment Response in a Young Boy with Achondroplasia

Background:

Achondroplasia is a skeletal dysplasia, the most common cause of rhizomelic dwarfism.

Case presentation:

This is a ten year old boy who was first diagnosed prenatally. He had a mutation c1138G>A in the gene FGFR3 in a heterozygotic constellation. His IGF1 and IGFBP3 levels were normal. Two stimulation tests for growth hormone were performed with values within the reference range. His psychomotor development was adequate for his age except for speech difficulty. He started with recombinant hGH (r-hGH) at the age of 3.4 years in a dose of 0.06 mg/kg. His mean Height SDS (HtSDS) was -2.2.

Results:

The growth increased to 10 cm/year in the first year of therapy (HtSDS -1.1). It decreased during the second year to 4 cm (HtSDS -1.7) and again increased during the third year to 8 cm/year (HtSDS–1.3). In the next years the growth was constant (6.5, 2.3, 3.5 cm / year). He is still growing in the 3^rd percentile of the growth curve (HtSDS – 1.2) under GH treatment. The body disproportion remained the same.

Conclusion:

The growth response on GH treatment was satisfactory in the first 4 years of treatment, and the boy still continued to grow. The young age at the start of treatment was also of importance. Our other patients with achondroplasia who started treatment older had a poor response to growth hormone.

Is the decision on the use of biosimilar growth hormone based on high quality scientific evidence? - a systematic review

BACKGROUND

The authors carried out a systematic and critical review of the scientific literature regarding the possible development of neutralising antibodies developed in patients treated with growth hormone biosimilars (defined as a drug expected to be similar to the originator or original pharmaceutical -European Medicines Agency) as compared to the reference drug. As a consequence, we discovered two major issues, namely, the poor quality of the comparative clinical trials and the poor quality of the antibody assays used during the trials.

METHODS

The literature review was performed according to the principle of the Cochrane Collaboration and SBU. The electronic literature search included the databases PubMed, EMBASE and The Cochrane Library up to December 2012. Two independent reviewers assessed abstracts and full-text articles.

RESULTS

The search identified 1,553 abstracts related to the subject. Only six articles contained data on biosimilar growth hormone or antibody results obtained with appropriate methods. None of the studies fulfilled the criteria for high quality randomised controlled trials. Qualitative rather than quantitative assays were used for monitoring antibody formation.

CONCLUSIONS

It is our firm opinion , that since biosimilars are not identical, emphasis must be placed on the quality of the comparative clinical trials performed and the quality of the analytical studies in order to guarantee patient safety. Clinical trials should follow established quality rules for controlled comparative randomised clinical trials. A whole set of new guidelines is required.

Should recombinant human growth hormone therapy be used in short small for gestational age children?

Short small for gestational age (SGA) children represent 20% of all children with short stature and therefore constitute a significant portion of the caseload in a growth clinic. The recent approval of recombinant human growth hormone (GH) for the treatment of short stature in SGA children by the European Union's Committee on Proprietary Medicinal Products offers a new licensed therapeutic option. This article examines the role of GH therapy in short SGA children with particular reference to selection of patients, effectiveness, safety, and its potential metabolic implications.

Growth hormone treatment in children: review of safety and efficacy

Since the advent of growth hormone (GH), the pediatric applications of GH therapy have expanded. Children with a wide variety of growth disorders have received GH treatment. The therapeutic effects and safety profile of GH in a number of pediatric conditions are reviewed, including GH deficiency (GHD), Turner syndrome, chronic renal failure, children born small for gestational age, Prader-Willi syndrome, juvenile chronic arthritis, and cystic fibrosis. GH therapy has been clearly shown to improve height velocity during childhood in a variety of pediatric conditions in which growth is compromised. There is now data that confirms GH treatment also improves final height in a number of diagnostic subgroups. Early initiation and individualization of GH treatment has the potential to normalize childhood growth in children with idiopathic GHD and enable them to achieve their genetic target height in a cost-effective manner. In children in whom GHD is not the main factor compromising growth, supra-physiological doses of GH have been shown to increase height velocity during childhood and final height. The development of predictive models for these conditions may allow further improvements in height outcome while maintaining an acceptable safety profile. Survivors of childhood malignancy, particularly those who have had craniospinal irradiation, represent a particularly challenging group. They appear to be less responsive to GH than children with idiopathic GHD and have a tendency to enter puberty at an earlier age. Both of these factors have a negative impact on their final height. Strategies that combine GH treatment with suppression of puberty using a gonadotropin releasing hormone analog may result in improved height outcomes. When children with GHD are treated with standard doses of GH there is a strong safety record. Adverse events during GH therapy are uncommon and often not drug related. Continued surveillance into adult life is crucial however, particularly in children receiving supra-physiological doses of GH or whose underlying condition increases their risk of adverse effects.

Linear catch-up growth

Chronic diseases and malnutrition cause growth failure in childhood and adolescence. Correction of the cause of a growth deficiency is usually followed by catch-up growth. Capacity to catch-up is not only variable in different phases of growth, it is also different in different diseases and among different individuals suffering from the same disease. Catch-up growth is of three types. In type 1 catch-up growth, height deficit is swiftly eliminated after the growth restriction ceases. In type 2, after growth restriction ceases growth continues for longer than usual and growth arrest is compensated. Type 3 is a mixture of type 1 and type 2. Repeated episodes of growth inhibitory conditions result in lower catch-up rates in the subsequent periods. Although the exact mechanism regulating catch-up growth still remains a mystery, monitoring catch-up growth remains an important measure of the efficacy of the therapy and therefore of immense clinical importance.