The Diversity of Biosimilar Design and Development: Implications for Policies and Stakeholders

Follicle-stimulating hormone sweetness: How carbohydrate structures impact on the biological function of the hormone

Follicle-stimulating hormone (FSH), or follitropin, exists in multiple molecular forms due largely to its protein-carbohydrate composition and the complexity of the glycans attached to the protein core. The heterogeneity of gonadotropins exists in two forms, macroheterogeneity, which results from the absence of one or two oligosaccharide chains in the ß-subunit, and microheterogeneity which results from variation in the structures and complexity of the glycans attached to the hormone. In the clinical arena, FSH compounds are widely used by fertility specialists to promote ovarian follicle growth and maturation to a preovulatory follicle containing a fertilization-competent oocyte. Several genetically engineered recombinant human FSH preparations have been added to the arsenal of follitropin preparations in several countries for the treatment of infertility, particularly in women attending assisted reproduction clinics. Although the primary structure of these recombinant proteins is identical to that of naturally occurring FSH, the cell context and variations in the production and purification processes may impact the glycosidic profile of the recombinant FSH macro- and micro-heterogeneity, which may potentially influence the pharmacokinetics and pharmacodynamics of the compound. This review concentrates on the structure-function correlates of follitropin, with emphasis on the physiological and biological importance of the carbohydrates attached to its protein core, including its pharmacokinetics and biological activity. Emphasis is placed on pituitary FSH, and the available data on the various recombinant FSH preparations employed in therapeutics are also discussed, considering that this gonadotropin represents the cornerstone for the treatment of infertility in modern assisted reproduction.

Efficacy and safety of two rituximab biosimilars for treating immune thrombocytopenia: a reference-product matched study

The emergence of rituximab biosimilars offers the prospect of significant savings to the healthcare system. However, these drugs have never been evaluated for treating immune thrombocytopenia (ITP). This was an observational, matched study. We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from the historic ITP-ritux registry. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. Response status was defined according to international criteria. We included 107 patients; 55 receiving Rixathon™ and 52 Truxima™. Three months after the first infusion of rituximab biosimilars, the overall response rate was 47/74 (63.5%) versus 76/142 (53.5%) for the matched controls receiving the reference product (p = .13). The 3-month overall response rate was 76.5% for Rixathon™ versus 51.5% for the matched control group (p = .01) and 21/40 (52.5%) for Truxima™ versus 41/74 (55.4%) for the matched controls (p = .81). For non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. Rituximab biosimilars seemed safe and effective for ITP treatment.

Comparative effectiveness of gonadotropins used for ovarian stimulation during assisted reproductive technologies (ART) in France: A real-world observational study from the French nationwide claims database (SNDS)

This comparative non-interventional study using data from the French National Health Database (Système National des Données de Santé) investigated real-world (cumulative) live birth outcomes following ovarian stimulation, leading to oocyte pickup with either originator recombinant human follicle-stimulating hormone (r-hFSH) products (alfa or beta), r-hFSH alfa biosimilars, or urinaries including mainly HP-hMG (menotropins), and marginally u-hFSH-HP (urofollitropin). Using data from 245,534 stimulations (153,600 women), biosimilars resulted in a 19% lower live birth (adjusted odds ratio (OR) 0.81, 95% confidence interval (CI) 0.76-0.86) and a 14% lower cumulative live birth (adjusted hazard ratio (HR) 0.86, 95% CI 0.82-0.89); and urinaries resulted in a 7% lower live birth (adjusted OR 0.93, 95% CI 0.90-0.96) and an 11% lower cumulative live birth (adjusted HR 0.89, 95% CI 0.87-0.91) versus originator r-hFSH alfa. Results were consistent across strata (age and ART strategy), sensitivity analysis using propensity score matching, and with r-hFSH alfa and beta as the reference group.

Follicle-Stimulating Hormone Biological Products: Does Potency Predict Clinical Efficacy?

Follicle-stimulating hormone (FSH), together with luteinizing hormone (LH) and human chorionic gonadotropin (hCG), plays a fundamental role in human reproduction. The discovery of FSH and other gonadotropins was a defining moment in our understanding of reproduction and led to the development of many treatments for infertility. In this regard, exogenous FSH has been used to treat infertility in women for decades. Today, several recombinant and highly purified urinary forms of FSH are used in medically assisted reproduction (MAR). However, differences in the macro- and micro-heterogeneity of FSH result in a variety of FSH glycoforms, with glycoform composition determining the bioactivity (or potency), pharmacokinetic/pharmacodynamic (PK/PD) profiles, and clinical efficacy of the different forms of FSH. This review illustrates how the structural heterogeneity of FSH glycoforms affects the biological activity of human FSH products, and why potency does not predict effects in humans in terms of PK, PD, and clinical response.

Comparative Assessment of the Structural Features of Originator Recombinant Human Follitropin Alfa Versus Recombinant Human Follitropin Alfa Biosimilar Preparations Approved in Non-European Regions

Although the full primary structures of the alfa and beta subunits of reference r-hFSH-alfa and its biosimilars are identical, cell context-dependent differences in the expressing cell lines and manufacturing process can lead to variations in glycosylation profiles. In the present study, we compared the structural features of reference r-hFSH-alfa with those of five biosimilar preparations approved in different global regions outside Europe (Primapur^®, Jin Sai Heng^®, Follitrope^®, Folisurge^®, and Corneumon^®) with respect to glycosylation, macro- and microheterogeneity, and other post-translational modifications and higher order structure. The mean proportion of N-glycosylation-site occupancy was highest in reference r-hFSH-alfa, decreasing sequentially in Primapur, Jin Sai Heng, Corneumon, Follisurge and Follitrope, respectively. The level of antennarity showed slightly higher complexity in Corneumon, Primapur and Follitrope versus reference r-hFSH-alfa, whereas Jin Sai Heng and Folisurge were aligned with reference r-hFSH-alfa across all N-glycosylation sites. Sialylation level was higher in Corneumon and Follitrope, but small differences were detected in other biosimilar preparations compared with reference r-hFSH-alfa. Jin Sai Heng showed higher levels of N-glyconeuramic acid than the other preparations. Minor differences in oxidation levels were seen among the different products. Therefore, in summary, we identified var ious differences in N-glycosylation occupancy, antennarity, sialylation and oxidation between reference r-hFSH-alfa and the biosimilar preparations analyzed.

The Challenges of Switching Therapies in an Evolving Multiple Biosimilars Landscape: A Narrative Review of Current Evidence

With the increasing availability of biosimilars, the practice of switching therapies for non-medical reasons between an originator biologic and an analogous biosimilar has become more common. The evidence to support this practice mostly comes from single-switch randomized controlled trials (RCTs) and real-world (RW) evidence studies. However, as more biosimilars of the same originator enter the market, multiple switching events between originators and biosimilars is becoming a reality, despite limited evidence to support the efficacy and safety of such practice. Some countries have established guidelines, policies, or laws related to interchangeability and/or automatic substitution, whereas others have left these practices unregulated or controlled by other components of the healthcare system. Collectively, guidelines on single non-medical switching are often vague, with even less focus given to multiple non-medical switching, leaving this practice mostly unregulated. This narrative review will first discuss the current regulatory perspectives on non-medical switching and challenges associated with switching therapies, particularly with the availability of multiple biosimilars. We will then review the current evidence from RCTs and RW studies in the light of three different multiple-switch scenarios currently taking place in clinical practice: switching between an originator and a single biosimilar, switching between biosimilars of the same originator, and the clinical practice of switching back to the originator (i.e., switchbacks) after a failure of the initial non-medical switch to the analogous biosimilar.

Clinical and Regulatory Considerations for the Use of Bevacizumab Biosimilars in Metastatic Colorectal Cancer

Biosimilars - biological medicines highly similar to a licensed reference product (RP) - can mitigate the risk of drug shortages by providing treatment alternatives and, with their lower costs, increase patient access to medication and reduce health care expenditure. However, limited knowledge of biosimilar approval processes and lack of confidence in their quality and efficacy can limit their uptake. Importantly, biosimilars are approved based on tightly controlled regulatory pathways to demonstrate that the physical, chemical, and biological properties of the proposed biosimilar are highly similar to the RP, with no clinically meaningful differences. Initially, a battery of highly sensitive in vitro studies are performed, comparing critical quality attributes between the proposed biosimilar and RP. Subsequently, in vivo pharmacodynamic studies compare the activity and physiologic effects of the biosimilar and RP. Finally, clinical studies are conducted, including a pharmacokinetic equivalence study and a confirmatory comparative clinical trial. The latter is performed in the most sensitive patient population for which the RP is licensed, to provide the greatest possibility of identifying any clinically meaningful differences between the proposed biosimilar and RP. When equivalent safety and efficacy have been demonstrated in one setting, the totality of evidence, together with scientific justification that there are no anticipated differences between the RP and proposed biosimilar in mechanism of action, pharmacokinetics, immunogenicity or toxicity, allows extrapolation into indications where clinical studies were not performed with the proposed biosimilar. Here, we review the approval process for biosimilars, focusing on the licensing of bevacizumab biosimilars and their extrapolation to metastatic colorectal cancer.

Electron microscopy-based semi-automated characterization of aggregation in monoclonal antibody products

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Size-based quantification of small heterogeneous proteins using electron microscopy.

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Electron microscopy as an orthogonal tool for characterizing protein aggregates.

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Quick assessment of small heterogeneous proteins via softEM, a GUI-based algorithm.

Aggregation is a critical parameter for protein-based therapeutics, due to its impact on the immunogenicity of the product. The traditional approach towards characterization of such products is to use a collection of orthogonal tools. However, the fact that none of these tools is able to completely classify the distribution and physical characteristics of aggregates, implies that there exists a need for additional analytical methods. We report one such method for characterization of heterogeneous population of proteins using transmission electron microscopy. The method involves semi-automated, size-based clustering of different protein species from micrographs. This method can be utilized for quantitative characterization of heterogeneous populations of antibody/protein aggregates from TEM images of proteins, and may also be applicable towards other instances of protein aggregation.

Glycan Residues Balance Analysis - GReBA: A novel model for the N-linked glycosylation of IgG produced by CHO cells

The structure of N-linked glycosylation is a very important quality attribute for therapeutic monoclonal antibodies. Different carbon sources in cell culture media, such as mannose and galactose, have been reported to have different influences on the glycosylation patterns. Accurate prediction and control of the glycosylation profile are important for the process development of mammalian cell cultures. In this study, a mathematical model, that we named Glycan Residues Balance Analysis (GReBA), was developed based on the concept of Elementary Flux Mode (EFM), and used to predict the glycosylation profile for steady state cell cultures. Experiments were carried out in pseudo-perfusion cultivation of antibody producing Chinese Hamster Ovary (CHO) cells with various concentrations and combinations of glucose, mannose and galactose. Cultivation of CHO cells with mannose or the combinations of mannose and galactose resulted in decreased lactate and ammonium production, and more matured glycosylation patterns compared to the cultures with glucose. Furthermore, the growth rate and IgG productivity were similar in all the conditions. When the cells were cultured with galactose alone, lactate was fed as well to be used as complementary carbon source, leading to cell growth rate and IgG productivity comparable to feeding the other sugars. The data of the glycoprofiles were used for training the model, and then to simulate the glycosylation changes with varying the concentrations of mannose and galactose. In this study we showed that the GReBA model had a good predictive capacity of the N-linked glycosylation. The GReBA can be used as a guidance for development of glycoprotein cultivation processes.

Practical Guidance on Biosimilars, With a Focus on Latin America: What Do Rheumatologists Need to Know?

BACKGROUND/HISTORICAL PERSPECTIVE

Availability of biologic disease-modifying antirheumatic drugs (bDMARDs) has improved clinical outcomes in rheumatoid arthritis, but it also increased the cost of treatment. Biosimilars, the regulated copies of biologic products, have a potential to reduce health care costs and expand access to treatment. However, because of a complex development process, biosimilars can be considered only those noninnovator biologics with satisfactory supporting evidence (ranging from structural to clinical), as outlined in the recommendations by the World Health Organization (WHO). In Latin America, a heterogeneous regulatory landscape and nonconsistent approval practices for biosimilars create decision-making challenges for practicing rheumatologists.

SUMMARY OF LITERATURE

Most Latin American countries either have adopted or are in the process of adopting guidelines for the approval of biosimilars. However, among several marketed bDMARDs in the region, currently there are only 2 products that could be considered true biosimilars, based on the WHO criteria. The rest can be considered only intended copies, whose safety and efficacy are not fully established. One such product had to be withdrawn from the market because of safety concerns.

CONCLUSIONS AND FUTURE DIRECTIONS

Practicing rheumatologists in Latin America need to understand the regulatory situation for biosimilars in their countries. When considering bDMARDs that are not innovator products, clinicians should use only those that have been approved according to the WHO recommendations. For clarification, local health authorities or professional associations should be contacted.

Biosimilars: Considerations for Payers

Evaluating biosimilars requires payers to go beyond cost considerations: safety and efficacy, reliability of supply and logistics, and the impact of state laws on substitution and interchangeability must all be deliberated.

Direct quality control of glycoengineered erythropoietin variants

Recombinant production of glycoprotein therapeutics like erythropoietin (EPO) in mammalian CHO cells rely on the heterogeneous N-glycosylation capacity of the cell. Recently, approaches for engineering the glycosylation capacities of mammalian cells for custom designed glycoforms have been developed. With these opportunities there is an increasing need for fast, sensitive, and global analysis of the glycoproteoform landscape produced to evaluate homogeneity and consistency. Here we use high-resolution native mass spectrometry to measure the glycoproteoform profile of 24 glycoengineered variants of EPO. Based on the unique mass and intensity profiles of each variant, we classify them according to similarities in glycosylation profiles. The classification distinguishes EPO variants with varying levels of glycan branchingand sialylation, which are crucial parameters in biotherapeutic efficacy. We propose that our methods could be of great benefit in the characterization of other glycosylated biopharmaceuticals, ranging from the initial clonal selection to batch-to-batch controls, and the assessment of similarity between biosimilar/biobetter products.

Erythropoiesis and chronic kidney disease-related anemia: From physiology to new therapeutic advancements

Erythropoiesis is triggered by hypoxia and is strictly regulated by hormones, growth factors, cytokines, and vitamins to ensure an adequate oxygen delivery to all body cells. Abnormalities in one or more of these factors may induce different kinds of anemia requiring different treatments. A key player in red blood cell production is erythropoietin. It is a glycoprotein hormone, mainly produced by the kidneys, that promotes erythroid progenitor cell survival and differentiation in the bone marrow and regulates iron metabolism. A deficit in erythropoietin synthesis is the main cause of the normochromic normocytic anemia frequently observed in patients with progressive chronic kidney disease. The present review summarizes the most recent findings about each step of the erythropoietic process, going from the renal oxygen sensing system to the cascade of events induced by erythropoietin through its own receptor in the bone marrow. The paper also describes the new class of drugs designed to stabilize the hypoxia-inducible factor by inhibiting prolyl hydroxylase, with a discussion about their metabolism, disposition, efficacy, and safety. According to many trials, these drugs seem able to simulate tissue hypoxia and then stimulate erythropoiesis in patients affected by renal impairment. In conclusion, the in-depth investigation of all events involved in erythropoiesis is crucial to understand anemia pathophysiology and to identify new therapeutic strategies, in an attempt to overcome the potential side effects of the commonly used erythropoiesis-stimulating agents.

The sweet spot for biologics: recent advances in characterization of biotherapeutic glycoproteins

INTRODUCTION

Glycosylation is recognized as a Critical Quality Attribute for therapeutic glycoproteins such as monoclonal antibodies, fusion proteins and therapeutic replacement enzymes. Hence, efficient and quantitative glycan analysis techniques have been increasingly important for their discovery, development and quality control. The aim of this review is to highlight relevant and recent advances in analytical technologies for characterization of biotherapeutic glycoproteins. Areas covered: The review gives an overview of the glycosylation trends of biotherapeutics approved in 2016 and 2017 by FDA. It describes current and novel analytical technologies for characterization of therapeutic glycoproteins and is explored in the context of released glycan, glycopeptide or intact glycoprotein analysis. Ultra performance liquid chromatography, mass spectrometry and capillary electrophoresis technologies are explored in this context. Expert commentary: There is a need for the biopharmaceutical industry to incorporate novel state of the art analytical technologies into existing and new therapeutic glycoprotein workflows for safer and more efficient biotherapeutics and for the improvement of future biotherapeutic design. Additionally, at present, there is no 'gold-standard' approach to address all the regulatory requirements and as such this will involve the use of orthogonal glycoanalytical technologies with a view to gain diagnostic information about the therapeutic glycoprotein.

International standards for monoclonal antibodies to support pre- and post-marketing product consistency: Evaluation of a candidate international standard for the bioactivities of rituximab

The intrinsic complexity and heterogeneity of therapeutic monoclonal antibodies is built into the biosimilarity paradigm where critical quality attributes are controlled in exhaustive comparability studies with the reference medicinal product. The long-term success of biosimilars will depend on reassuring healthcare professionals and patients of consistent product quality, safety and efficacy. With this aim, the World Health Organization has endorsed the need for public bioactivity standards for therapeutic monoclonal antibodies in support of current controls. We have developed a candidate international potency standard for rituximab that was evaluated in a multi-center collaborative study using participants' own qualified Fc-effector function and cell-based binding bioassays. Dose-response curve model parameters were shown to reflect similar behavior amongst rituximab preparations, albeit with some differences in potency. In the absence of a common reference standard, potency estimates were in poor agreement amongst laboratories, but the use of the candidate preparation significantly reduced this variability. Our results suggest that the candidate rituximab standard can support bioassay performance and improve data harmonization, which when implemented will promote consistency of rituximab products over their life-cycles. This data provides the first scientific evidence that a classical standardization exercise allowing traceability of bioassay data to an international standard is also applicable to rituximab. However, we submit that this new type of international standard needs to be used appropriately and its role not to be mistaken with that of the reference medicinal product.

Glycosylation and antiproliferative activity of hyperglycosylated IFN-α2 potentiate HEK293 cells as biofactories

Both CHO and HEK cells are interesting hosts for the production of biotherapeutics due to their ability to introduce post-translational modifications such as glycosylation. Even though oligosaccharide structures attached to proteins are conserved among eukaryotes, many differences have been found between therapeutic glycoproteins expressed in hamster and human derived cells. In this work, a hyperglycosylated IFN-α2b mutein (IFN4N) was produced in CHO and HEK cell lines and an extensive characterization of their properties was performed. IFN4N_CHO exhibited a higher average molecular mass and more acidic isoforms compared to IFN4N_HEK. In agreement with these results, a 2-times higher sialic acid content was found for IFN4N_CHO in comparison with the HEK-derived protein. This result was in agreement with monosaccharide quantification and glycan's analysis using WAX chromatography and HILIC coupled to mass spectrometry; all methods supported the existence of highly sialylated and also branched structures for IFN4N_CHO glycans, in contrast with smaller and truncated structures among IFN4N_HEK glycans. Unexpectedly, those remarkable differences in the glycosylation pattern had not a considerable impact on the clearance rate of both molecules in rats. In fact, although IFN4N_HEK reached maximum plasma concentration 3-times faster than IFN4N_CHO, their elimination profile did not differ significantly. Also, despite the in vitro antiviral specific biological activity of both proteins was the same, IFN4N_HEK was more efficient as an antiproliferative agent in different tumor-derived cell lines. Accordingly, IFN4N_HEK showed a higher in vivo antitumor activity in animal models. Our results show the importance of an appropriate host selection to set up a bioprocess and potentiate the use of HEK293 cells for the production of a new hyperglycosylated protein-based pharmaceutical.