Availability and quality of illegitimate somatropin products obtained from the Internet.

Background Growth hormones are widely available on the Internet for those who want to enhance their physical performance and improve body satisfaction. Illegitimate websites market somatropin injections without medical prescription and encourage misuse. Customers potentially put their health at risk when purchasing parenteral medications online. Objective The objective of our study was to evaluate the online market of no-prescription somatropin products and to analyse and document Internet pharmacy characteristics, distribution and pharmaceutical quality. Setting Websites indexed in Google promoting somatropin for sale direct to patients. Method Websites promoting the sale of growth hormone products were identified and analysed from June to August 2014. Internet vendor sites were evaluated to identify possible patient and medication safety concerns. Website characteristics, delivery time, storage conditions, packaging and attached product information were assessed. Investigation of the somatropin content was achieved using capillary electrophoresis with UV detection and electrospray ionization mass spectrometry. Main outcome measure Accessibility and quality of somatropin injections. Results Seventeen individual Internet vendor websites distributed somatropin products directly to patients, majority (94%) did not require a valid medical prescription before dispensing the products. Majority (70%) of Internet pharmacies displayed no medical information and none (0%) of the vendors displayed any regulatory body logo. All online samples had significantly (p < 0.001) lower somatropin concentration than labelled. Conclusion Our results clearly illustrate that prescription only biologic drugs are widely available online and can be easily accessed by anyone. Unprofessional distribution and handling is likely to cause degradation and possible patient safety concerns.

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.

[What doctors need to know about biosimilar medicinal products?]. / Sto bi lijecnici trebali znati o bioloski slicnim lijekovima?

Biological drug is a drug containing one or more active substances produced or secreted from a biological source. Some of them may be previously present in the human body, and examples include proteins such as insulin, growth hormone or erythropoetin. Biosimilar drug is a medical product that is a copy of the original approved drug whose patent has expired. Strict rules apply to similar biological medicines: 1) it is unable to support extrapolation of data on safety and efficacy between individual indications, except in the case of appropriate, science-based evidence; 2) biosimilar drugs must meet the requirements associated with testing the immunogenicity and safety monitoring afterthe introduction of the drug in clinical practice, including the risk management program; 3) each biosimilar drug has to be labeled under its own name in order to allow clear traceability of all medications; and 4) the principle of automatic substitution cannot apply to biosimilar drugs because they are not interchangeable.

Gaps in the traceability chain of human growth hormone measurements.

BACKGROUND: Human growth hormone (hGH) is measured for the diagnosis of secretion disorders. These measurements fall under the EU Directive 98/79/EC on in vitro diagnostic medical devices requiring traceability of commercial calibrator values to higher-order reference materials or procedures (Off J Eur Communities 1998 Dec 7;L 331:1-37). External quality assessment schemes show large discrepancies between results from different methods, even though most methods provide results traceable to the recommended International Standard (IS 98/574). The aim of this study was to investigate possible causes for these discrepancies. METHODS: We investigated the commutability and recovery of hGH in reconstituted IS 98/574. We tested different reconstitution protocols and used 4 different serum matrices for spiking. These IS preparations were measured together with serum samples. We quantified hGH by 5 different methods in 4 different laboratories. RESULTS: Results from the different methods correlated well for the serum samples. Mean discrepancies between results from different methods were ≤20%. None of the IS preparations was commutable for all the method comparisons. The recovery of hGH in preparations of IS 98/574 depended on the reconstitution protocol (>10-fold differences) and background matrix (relative differences ≤17% for different serum matrices). CONCLUSIONS: The use of different protocols for reconstitution and spiking of hGH reference preparations affects quantification by immunoassays, potentially leading to a bias between commercial methods, despite the use of calibrators with values claimed to be traceable to the same higher-order reference material.

Fully traceable absolute protein quantification of somatropin that allows independent comparison of somatropin standards.

BACKGROUND: Measurement traceability in clinical chemistry is required to standardize clinical results irrespective of the measurement procedure and laboratory. The traceability of many protein substances is maintained by reference to the first standard produced, which may no longer exist, with values assigned by consensus. Independent methods that provide traceability to the Système d'Unité International for all relevant properties of a protein standard could remove reliance on the original standard preparations. METHODS: We developed a method based on the traceable quantification of tryptic peptides released from the protein by isotope dilution mass spectrometry to compare 2 standard preparations of somatropin (recombinant human growth hormone), WHO 98/574 and Ph.Eur.CRS S0947000. Relative quantification using isotope-coded affinity tagging, isobaric tagging for relative and absolute quantification, and standard additions were also performed to validate the digestion method used and to determine whether any modifications were present. RESULTS: The total somatropin content in both materials was determined and an uncertainty estimation undertaken [WHO 2.19 +/- 0.21) mg/vial, European Pharmacopeia 2.06 +/- 0.21 mg/vial]. Each uncertainty in this paper is a fully estimated uncertainty, with 95% CI (k = 2). Isotope coded affinity tag and standard addition results fully validated the robustness of the digestion method used. In addition, iTRAQ (isobaric tagging for relative and absolute quantification analysis) identified 2 modifications, neither of which impacted the quantification. CONCLUSIONS: An independent method that does not rely on a preexisting protein standard has been developed and validated for the traceable value-assignment of total somatropin. The methods reported here address the amount of substance (mass fraction) of the standard materials but address neither biological activity nor other characteristics that may be important in assessing suitability for use as a calibrator.

Establishment of reference values for endocrine tests. Part VII: growth hormone deficiency.

BACKGROUND: Plasma insulin-like growth factor (IGF-I) concentration can be used as a rough indicator of the growth-hormone status. However, for the diagnosis of growth hormone deficiency, dynamic tests are required. The growth hormone (GH) response in the insulin tolerance test (ITT) is considered to be the gold standard in this respect. An alternative for the ITT is the GHRH/ GHRP-6 test, which has fewer side effects. In this study we established reference values for IGF-I levels and for the GH response in both dynamic tests. METHODS: We studied 296 subjects recruited from the general population, equally distributed according to sex and aged between 20 and 70 years. Serum IGF-I level was measured in all subjects and an insulin tolerance test (0.15 U/kg Actrapid iv) and GHRH/GHRP-6 test (1 microg GHRH/kg and 1 microg GHRP-6/kg) were performed in 49 subjects. RESULTS: In multivariate analyses both IGF-I and the GH response in the ITT were significantly influenced by age, whereas the GH response in the GHRH/GHRP-6 test was significantly affected by BMI. There was no sex difference in IGF-I and in the GHRH/GHRP-6 test, but in the ITT males had a higher GH peak. There was a significant correlation between the GH responses in both tests, and the GH response was significantly higher in the GHRH/GHRP-6 test than in the ITT. Age-adjusted reference values were established for each test. CONCLUSION: We have established age-adjusted reference values for serum IGF-I and for the GH response in the ITT and GHRH/GHRP-6 test.

Standardization of the IMMULITE systems growth hormone assay with the recombinant IS 98/574.

BACKGROUND: The diagnosis of disorders of growth hormone (GH) secretion is based on the measurement of GH before and after dynamic stimulation or suppression tests. Over the years, specific cut-off values have been proposed without taking account of the considerable variation in results obtained using different methods for analysing GH. Recent publications have recommended the standardization of GH assays using IS 98/574, which is calibrated in mass and units (U). The IMMULITE range of GH assays have been recalibrated using this standard. METHODS: We analysed 745 samples using the current and the restandardized GH assay kits. This series of samples contained 90 stimulation tests and seven suppression tests. RESULTS: The data comparing the current and restandardized assays show a similar relationship for both basal and stimulated GH values for all IMMULITE platforms. There is a negative bias by the restandardized assay above approximately 20 microg/L. A conversion can be derived from this study which would mean that patient GH results expressed in milliunits per litre of IMMULITE in-house derived standard will be approximately three-fold of that expressed in micrograms per litre of IS 98/574. CONCLUSION: Use of IS 98/574 offers standardized reporting in microgram per litre IS 98/574. This will permit compliance with the consensus recommendations and the development of a firm evidence base for defining decision-making GH values.

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.

Similar biological medicinal products containing recombinant human growth hormone: European regulation.

The concept of similar biological medicinal products ('biosimilar' medicinal products) allows pharmaceutical companies to develop products based on an abridged dossier once the marketing protection of the 'reference' biological medicinal product has expired. A biosimilar medicinal product can be granted a marketing authorization provided that its similarity to a reference product is established in terms of quality, safety and efficacy (step-wise comparability exercise). A decision to launch a biosimilar medicinal product on the market is taken if it has a similar efficacy and comparable or better (less) immunogenicity than the chosen reference biological medicinal product. However, this decision is based on limited data and the comparability program may detect substantial differences in immunogenicity profiles but is likely incapable of detecting rare events. This is why clinical experience, through clinical trials and extensive pharmacovigilance programs, remains the most reliable way to assess the immunogenicity and tolerance profile of recombinant therapeutic proteins. Substitution of one biological medicinal product by a biosimilar medicinal product is not currently recommended before long-term clinical efficacy and safety have been acquired in all relevant populations. Here we review recent regulatory guidelines provided by EMEA and comment on the marketing authorizations and risk management plans of two recently approved biosimilar somatropins.

Defining normalcy of the somatotropic axis: an attainable goal?

The diagnoses of acromegaly and dwarfism require biochemical confirmation of abnormal GH and IGF-1 concentrations. The same parameters are used for therapeutic decisions, i.e. initiation or termination of particular treatments. Therefore, reliable and epidemiologically and statistically proven criteria of normalcy for GH and IGF-1 are required for these tasks to be accomplished. Despite major progress in all these areas, the definition of what constitutes "normalcy" of the somatotropic axis is still lacking. Using an example of acromegaly, we discuss the contradictions and the uncertainties of the biochemical diagnosis of this disease.

IGF-I measurements in the monitoring of GH therapy.

Growth hormone replacement therapy has been used regularly in adult Growth hormone deficiency since the availability of recombinant GH in the 1980's. GH replacement improves quality of life, bone turnover markers, cardiovascular risk markers and adverse body composition. Originally, GH doses in replacement regimes were determined by weight and surface area and dose increases based on body composition outcomes analogous to pediatric practice. These regimens led to significant side effects related to excess GH, arthralgias, headaches and peripheral edema and IGF-I levels above the upper limit of the reference range. Newer treatment regimes therefore account for known factors affecting serum GH and IGF-I levels, i.e. age, gender, estrogen replacement and pre-treatment IGF-I levels. Monitoring is now via clinical symptomatology combined with serum total IGF-I levels, potentially this avoids excessive GH exposure and allows monitoring of compliance and dose titration. There is a lack of data relating IGF-I to biological endpoints, but analysis suggests that dose titration of IGF-I to the upper half of the age and gender related reference range is acceptable. The use of reliable IGF-I assays and extensive age and gender related reference ranges is necessary and centralized monitoring is preferable. Free IGF-I and bioavailable IGF-I measurements are available but their use in the monitoring of GH replacement remains to be determined.

Collaborative study for the establishment of replacement batches for somatropin CRS batch 1.

A project was run for the establishment of replacement batches of the European Pharmacopoeia (Ph. Eur.) Somatropin Chemical Reference Substance (CRS) batch 1. Twenty two laboratories from 16 countries took part in a collaborative study aimed at demonstrating the suitability of the candidate reference preparations to serve as working references in the tests for identification by peptide mapping and capillary electrophoresis (CE); related proteins, dimers and related substances of higher molecular mass; charged variants distribution; and/or for the assay of somatropin, as performed in accordance with the specifications of the current Ph. Eur. monographs 0950 Somatropin bulk solution, 0951 Somatropin and 0952 Somatropin for injection. Further to the completion of the study the Ph. Eur. Commission adopted one candidate in March 2006 as somatropin CRS batch 2 (with an assigned content of 1.69 mg somatropin monomer per vial) and the second one in June 2006 as somatropin/desamidosomatropin resolution mixture CRS batch 1 (prescribed use of the latter standard is restricted to the test for related proteins).

Sperm analysis in growth hormone-deficient adolescents previously treated with an aromatase inhibitor: comparison with normal controls.

We performed two semen analyses in each of a small cohort of 11 GH-deficient (GHD) adolescents (mean age 18.1 +/- 0.6 yrs), previously treated (mean 29 months prior) with either GH alone or GH and an aromatase inhibitor (anastrozole) for 12 months and compared their data with those of 10 healthy controls (mean age 18.7 +/- 1.8 yrs). Although some adolescents had lower sperm parameters as compared to adult reference values, mean sperm concentrations, motility, and morphology were comparable among the 3 groups, suggestive that this small group of GHD adolescents previously treated with anastrozole has descriptively similar sperm parameters as other GHD and GH-sufficient adolescent controls.

Somatropin and its variants: structural characterization and methods of analysis.

Human Growth hormone (hGH, somatotrophin) is a 22 kDa, 191 amino-acid single chain protein produced by somatroph cells of the anterior pituitary gland. It is the major physiological regulator of growth, and deficiencies in growth hormone levels have long been recognized as the underlying cause of growth disorders (dwarfism). The ability of exogenous hGH to restore normal rates of growth in both human and animal models of growth retardation has long been recognized and the use of hGH in therapy goes back several decades. Initial preparations were prepared by extraction and purification from cadaveric pituitary tissue, and since 1984, hGH has been prepared by recombinant Deoxyribosenucleic acid (rDNA) technology. As is usually the case with "biologicals", characterization of the drug substance depended on a combination of physico-chemical and biological methods, and the hGH molecule became well characterized fairly early in its life as a drug. Indeed, by 1980 the major degradation forms and structural variants of the hGH molecule had been described and reviewed. Little satisfactory progress had been made in refining biological assays for hGH, and, although in vitro assays were described, potency-defining assays remained dependant on the whole body growth response in rats, and were both invasive and imprecise. In the early 1990's a series of collaborative studies on analysis of recombinant hGH (somatropin) established that available bioassays were much less selective that physico-chemical methods in detecting and quantifying structural degradation, and 1994 saw an international consensus to replace the bioassays with physico-chemical analytical methods for the routine batch release of somatropin. During the last decade in most markets somatropin has, unusually for a protein, been subject to batch release and control dependent entirely on physico-chemical analysis, without the routine use of any form of bioassay. During that time there has been a continuous development and refinement of methods, and the identification of a range of structural variants and degradation products of the molecule. The present review sets out to summarise the current knowledge on physico-chemical analytical methods for somatropin, and the structural variants that have been identified and characterized. A survey of available biological analytical methods is beyond the scope of this review, as is consideration of the earlier pituitary preparations and the recombinant 192 amino-acid methionyl form of the molecule (somatrem), although it is likely that many of the methods and variants described would be equally applicable to somatrem.

Capillary electrophoresis for the control of impurities of rDNA somatropin.

In the European Pharmacopoeia, the monographs on somatropin, somatropin bulk solution and somatropin for injection prescribe a number of tests including "related substances", "dimer and related substances of higher molecular weight" and "isoform distribution" which are intended to control the levels of impurities in the substance. The aim of this study was to verify the robustness of a new method by capillary electrophoresis and to compare its performance with that of the existing test for "isoform distribution" by isoelectric focusing. It was demonstrated that the capillary electrophoresis method was superior to the method of isoelectric focusing. The interest of the CZE method consists in the resolution of related impurities that might be process specific and/or generated by the expression system.

The Second International Standard for somatropin (recombinant DNA-derived human growth hormone): preparation and calibration in an international collaborative study.

A preparation of somatropin (recombinant DNA-derived human growth hormone) was prepared as lyophilised ampoules according to WHO procedures for international biological standards. The candidate preparation (98/574) was evaluated in an international collaborative study (16 laboratories, nine countries), with the following aims: (i) to determine the suitability of the preparation to serve as the International Standard for somatropin by studying its performance in the current range of physico-chemical and biological assay methods employed for somatropin; (ii) to assign a content in terms of the existing (first) International Standard for somatropin, using the currently recognised assay procedure (Size Exclusion High Performance Liquid Chromatography, SE HPLC); (iii) to confirm the specific biological activity of the candidate preparation; (iv) to confirm the stability of the candidate preparation. On the basis of the collaborative study WHO agreed that: the preparation in ampoules coded 98/574 is suitable to serve as the next WHO International Standard for somatropin; the preparation in ampoules coded 98/574 should be established as the second International Standard for somatropin, with a defined ampoule content of 1.95 mg total somatropin plus somatropin-related proteins per ampoule; the specific activity of the preparation should be defined as 3.0 IU/mg somatropin.