Switching to Omnitrope(®) from Other Recombinant Human Growth Hormone Therapies: A Retrospective Study in an Integrated Healthcare System

Ten years with biosimilar rhGH in clinical practice in Sweden - experience from the prospective PATRO children and adult studies

BACKGROUND

In 2007, Omnitrope® was the first biosimilar recombinant human growth hormone (rhGH) to be approved in Sweden for treatment in adults and children. Over 10 years' safety and effectiveness data for biosimilar rhGH can now be presented.

METHODS

PATRO Children and PATRO Adults are multicenter, longitudinal, observational, post-marketing surveillance studies. Eligible patients include children 0-18 years and adults receiving biosimilar rhGH treatment. Adverse events (AEs) are monitored for safety evaluation. Growth variables in children and metabolic data in adults are recorded for effectiveness evaluation.

RESULTS

As of January 2019, data from 136 children (48% male) were reported from Swedish centers. Mean age in rhGH treatment-naïve patients at study entry (n = 114) was 7.5 years, with mean 3.6 years treatment duration. No severe AEs of diabetes, impaired glucose tolerance, or malignancy were reported. The most frequently reported AE was nasopharyngitis (n = 16 patients). No clinically relevant anti-hGH or neutralizing antibodies were observed. The mean change from baseline in height standard deviation score (SDS) in naïve prepubertal GH deficiency patients was + 0.79 at 1 year, + 1.27 at 2 years, and + 1.55 at 3 years. Data from 293 adults (44% rhGH-naïve, 51% male) were included. Fatigue was the most frequently reported AE (n = 26 patients). The incidence of new neoplasms or existing neoplasm progression was 23.8 patients per 1000 patient-years. Type 2 diabetes mellitus was reported in four patients. At baseline in rhGH-naïve adults, mean (SD) body mass index (BMI) was 29.1 (5.6) kg/m2 and mean (SD) insulin-like growth factor (IGF)-I SDS was - 3.0 (1.4). Mean daily dose increased from 0.1 mg at baseline to 0.3 mg after 4 years. IGF-I SDS normalized during the first year of treatment. Mean BMI and glucose were unchanged over 4 years, while low-/high-density lipoprotein cholesterol ratio decreased.

CONCLUSIONS

For the first time, Swedish data from the PATRO Children and Adults studies are presented. The 10-year data suggest that biosimilar rhGH is well tolerated across pediatric and adult indications. Safety and effectiveness were similar to previous reports for other rhGH preparations. These results need to be confirmed in larger cohorts, highlighting the importance of long-term post-marketing studies.

Efficacy and Safety of Biosimilar Growth Hormone in Indian Children

OBJECTIVE

To study efficacy and safety of use of biosimilar growth hormone (GH) in Indian children with growth disorders.

MATERIALS AND METHODS

We studied 322 children (May 2012-2017) with growth disorders including growth hormone deficiency (GHD), multiple pituitary hormone deficiency (MPHD, idiopathic short stature (ISS), small for gestational age (SGA), and Turner syndrome (TS). Children were treated either with innovator molecule (Norditropin) or biosimilar GH (Headon) with standard dosage protocol for 1 year. Height and weight was measured using standard protocol. Height and BMI for age Z-scores (HAZ, BMIZ), height velocity (HV), and HV Z-score (HVZ) were computed from available data.

RESULTS

Mean age of the studied children (n = 322) was 9.6 ± 4.1 years, 32% children had GHD, 39% had ISS, 11% had MPHD, 12% had SGA, and 6% children had TS. There were no serious adverse events; three patients recorded eight instances of headaches, two had rash at injection site, and one each had hives and facial edema. Reactions were mild and were treated symptomatically. At the end of the 1 year of GH therapy, change in HAZ was similar in children from both the innovator and biosimilar GH groups. Similarly, the HV and HVZ were also similar in children from both groups and all the studied growth disorders.

CONCLUSION

Biosimilar GH was effective and safe for treatment in children with growth disorders where GH use is indicated. However, in the view of scarcity of such data a longitudinal study with large sample size is warranted.

Biosimilarity and Interchangeability: Principles and Evidence: A Systematic Review

BACKGROUND

The efficacy, safety and immunogenicity risk of switching between an originator biologic and a biosimilar or from one biosimilar to another are of potential concern.

OBJECTIVES

The aim was to conduct a systematic literature review of the outcomes of switching between biologics and their biosimilars and identify any evidence gaps.

METHODS

A systematic literature search was conducted in PubMed, EMBASE and Cochrane Library from inception to June 2017. Relevant societal meetings were also checked. Peer-reviewed studies reporting efficacy and/or safety data on switching between originator and biosimilar products or from one biosimilar to another were selected. Studies with fewer than 20 switched patients were excluded. Data were extracted on interventions, study population, reason for treatment switching, efficacy outcomes, safety and anti-drug antibodies.

RESULTS

The systematic literature search identified 63 primary publications covering 57 switching studies. The reason for switching was reported as non-medical in 50 studies (23 clinical, 27 observational). Seven studies (all observational) did not report whether the reasons for switching were medical or non-medical. In 38 of the 57 studies, fewer than 100 patients were switched. Follow-up after switching went beyond 1 year in eight of the 57 studies. Of the 57 studies, 33 included statistical analysis of disease activity or patient outcomes; the majority of these studies found no statistically significant differences between groups for main efficacy parameters (based on P < 0.05 or predefined acceptance ranges), although some studies observed changes for some parameters. Most studies reported similar safety profiles between groups.

CONCLUSIONS

There are important evidence gaps around the safety of switching between biologics and their biosimilars. Sufficiently powered and appropriately statistically analysed clinical trials and pharmacovigilance studies, with long-term follow-ups and multiple switches, are needed to support decision-making around biosimilar switching.

[Ten years experience with the first approved biosimilar recombinant human growth hormone drug in normal clinical practice]

INTRODUCTION

Recombinant human growth hormone (rhGH) is the first biosimilar drug approved by the European Medicines Agency in 2006, using the biosimilar registration process. It was authorised for the treatment of growth hormone deficiency, and growth disorders associated with Turner's syndrome, chronic renal failure, Prader-Willi syndrome, and growth disorders in children/adolescents born small for gestational age, and replacement therapy in adults with pronounced growth hormone deficiency.

MATERIALS AND METHODS

This review is focused on the scientific evidence published about this drug in the last ten years, including the clinical trials on which the approval of the regulatory authority is based, and the most relevant studies evaluating the clinical impact of the drug in clinical practice.

RESULTS

The equivalence between biosimilar and original product has been confirmed in the clinical trials published by Romer et al. and López-Siguero et al. Furthermore, studies carried out in real-life conditions confirm its long-term efficacy and safety, as well as the absence of clinical impact by switching treatment from the original to the biosimilar product.

CONCLUSION

The number of patients receiving this medication has continuously increased since its approval. Its equivalence with the original product has been verified. Preliminary data from the post-authorisation PATRO study confirm the efficacy and safety of the biosimilar product in comparison with data from clinical trials. However, final results must be evaluated at the end of the study, which will provide additional information about the long-term efficacy and safety of the biosimilar drug.

Ten years of biosimilar recombinant human growth hormone in Europe

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.

Ten years' clinical experience with biosimilar human growth hormone: a review of efficacy data

In 2006, the European Medicines Agency (EMA) approved Omnitrope^® as a biosimilar recombinant human growth hormone (rhGH), on the basis of comparable quality, safety, and efficacy to the reference medicine (Genotropin^®, Pfizer). Data continue to be collected on the long-term efficacy of biosimilar rhGH from several on-going postapproval studies. Particular topics of interest include efficacy in indications granted on the basis of extrapolation, and whether efficacy of growth hormone treatment is affected when patients are changed to biosimilar rhGH from other rhGH products. Data from clinical development studies and 10 years of postapproval experience affirm the clinical efficacy and effectiveness of biosimilar rhGH across all approved indications. In addition, the decade of experience with biosimilar rhGH since it was approved in Europe confirms the scientific validity of the biosimilar pathway and the approval process. Concerns about clinical effect in extrapolated indications, and also about the impact of changing from other rhGH preparations, have been alleviated. Biosimilar rhGH is an effective treatment option for children who require therapy with rhGH.

Ten years of clinical experience with biosimilar human growth hormone: a review of safety data

Safety concerns for recombinant human growth hormone (rhGH) treatments include impact on cancer risk, impact on glucose homeostasis, and the formation of antibodies to endogenous/exogenous GH. Omnitrope^® (biosimilar rhGH) was approved by the European Medicines Agency in 2006, with approval granted on the basis of comparable quality, safety, and efficacy to the reference medicine (Genotropin^®). Additional concerns that may exist in relation to biosimilar rhGH include safety in indications granted on the basis of extrapolation and the impact of changing to biosimilar rhGH from other rhGH treatments. A substantial data set is available to fully understand the safety profile of biosimilar rhGH, which includes data from its clinical development studies and 10 years of post-approval experience. As of June 2016, 106,941,419 patient days (292,790 patient-years) experience has been gathered for biosimilar rhGH. Based on the available data, there have been no unexpected or unique adverse events related to biosimilar rhGH treatment. There is no increased risk of cancer, adverse glucose homeostasis, or immunogenic response with biosimilar rhGH compared with the reference medicine and other rhGH products. The immunogenicity of biosimilar rhGH is also similar to that of the reference and other rhGH products. Physicians should be reassured that rhGH products have a good safety record when used for approved indications and at recommended doses, and that the safety profile of biosimilar rhGH is in keeping with that of other rhGH products.

Interchangeability of Biosimilars: A European Perspective

Many of the best-selling 'blockbuster' biological medicinal products are, or will soon be, facing competition from similar biological medicinal products (biosimilars) in the EU. Biosimilarity is based on the comparability concept, which has been used successfully for several decades to ensure close similarity of a biological product before and after a manufacturing change. Over the last 10 years, experience with biosimilars has shown that even complex biotechnology-derived proteins can be copied successfully. Most best-selling biologicals are used for chronic treatment. This has triggered intensive discussion on the interchangeability of a biosimilar with its reference product, with the main concern being immunogenicity. We explore the theoretical basis of the presumed risks of switching between a biosimilar and its reference product and the available data on switches. Our conclusion is that a switch between comparable versions of the same active substance approved in accordance with EU legislation is not expected to trigger or enhance immunogenicity. On the basis of current knowledge, it is unlikely and very difficult to substantiate that two products, comparable on a population level, would have different safety or efficacy in individual patients upon a switch. Our conclusion is that biosimilars licensed in the EU are interchangeable.

Interchangeability among reference insulin analogues and their biosimilars: regulatory framework, study design and clinical implications

Biosimilars are regulated differently from small-molecule generic, chemically derived medicines. The complexity of biological products means that small changes in manufacturing or formulation may result in changes in efficacy and safety of the final product. In the face of this complexity, the regulatory landscape for biosimilars continues to evolve, and global harmonization regarding requirements is currently lacking. It is essential that clinicians and patients are reassured that biosimilars are equally safe and effective as their reference product, and this is particularly important when interchangeability, defined as 'changing one medicine for another one which is expected to achieve the same clinical effect in a given clinical setting in any one patient', is considered. Although the automatic substitution (i.e. substitution without input from the prescribing healthcare provider) of biosimilars for reference products is currently not permitted by the majority of countries, this may change in the future. In order to demonstrate interchangeability between reference products and a biosimilar, more stringent and specific studies of the safety and efficacy of biosimilars are likely to be needed; however, guidance on the design of and the need for any such studies is currently limited. The present article provides an overview of the current regulatory framework around the demonstration of interchangeability with biosimilars, with a specific focus on biosimilar insulin analogues, and details experiences with other biosimilar products. In addition, designs for studies to evaluate interchangeability with a biosimilar insulin analogue product are proposed and a discussion about the implications of interchangeability in clinical practice is included.