Rituximab biosimilars

Current state and comparison of the clinical development of bevacizumab, rituximab and trastuzumab biosimilars

Monoclonal antibodies are highly complex, large and biologic products with a substantial impact on the clinical management of a variety of diseases including cancer. The expiry of patents for essential monoclonal antibodies in cancer care such as bevacizumab, rituximab and trastuzumab, has prompted the global development of biosimilars to balance the biologics market. However, an understanding of the different approach of biosimilar development compared with its reference medicinal product, especially in the context of clinical trial design and end point selection may help oncologists integrating biosimilars into clinical practice. Herein, we reviewed the clinical development of biosimilars in oncology comparing the available clinical data of proposed biosimilars of bevacizumab, rituximab and trastuzumab.

Hydrogen deuterium exchange mass spectrometry identifies the dominant paratope in CD20 antigen binding to the NCD1.2 monoclonal antibody

A comparative canine–human therapeutics model is being developed in B-cell lymphoma through the generation of a hybridoma cell that produces a murine monoclonal antibody specific for canine CD20. The hybridoma cell produces two light chains, light chain-3, and light chain-7. However, the contribution of either light chain to the authentic full-length hybridoma derived IgG is undefined. Mass spectrometry was used to identify only one of the two light chains, light chain-7, as predominating in the full-length IgG. Gene synthesis created a recombinant murine–canine chimeric monoclonal antibody expressing light chain-7 that reconstituted the IgG binding to CD20. Using light chain-7 as a reference sequence, hydrogen deuterium exchange mass spectrometry was used to identify the dominant CDR region implicated in CD20 antigen binding. Early in the deuteration reaction, the CD20 antigen suppressed deuteration at CDR3 (V_H). In later time points, deuterium suppression occurred at CDR2 (V_H) and CDR2 (V_L), with the maintenance of the CDR3 (V_H) interaction. These data suggest that CDR3 (V_H) functions as the dominant antigen docking motif and that antibody aggregation is induced at later time points after antigen binding. These approaches define a methodology for fine mapping of CDR contacts using nested enzymatic reactions and hydrogen deuterium exchange mass spectrometry. These data support the further development of an engineered, synthetic canine–murine monoclonal antibody, focused on CDR3 (V_H), for use as a canine lymphoma therapeutic that mimics the human–murine chimeric anti-CD20 antibody Rituximab.

Efficacy, Safety and Pharmacokinetics of Up to Two Courses of the Rituximab Biosimilar CT-P10 Versus Innovator Rituximab in Patients with Rheumatoid Arthritis: Results up to Week 72 of a Phase I Randomized Controlled Trial

Background

CT-P10 is a biosimilar of innovator rituximab (RTX), a biological therapy used to treat patients with rheumatoid arthritis (RA) who have responded inadequately to anti-tumor necrosis factor agents.

Objective

Our objective was to compare the clinical profile of CT-P10 versus RTX in patients with RA who received up to two courses of treatment and were followed for up to 72 weeks.

Methods

In this multicenter double-blind phase I study, patients were randomized 2:1 to receive CT-P10 1000 mg or RTX 1000 mg at weeks 0 and 2. Based on disease activity, patients could receive a second course of treatment between weeks 24 and 48. Efficacy endpoints, including mean change from baseline in Disease Activity Score using 28 joints (DAS28), safety, immunogenicity, pharmacokinetics, and pharmacodynamics were evaluated.

Results

In total, 154 patients were randomized to CT-P10 or RTX (n = 103 and 51, respectively); 137 (n = 92 and 45) completed the first course of treatment, of whom 83 (n = 60 and 23) were re-treated. Improvements from baseline in all efficacy endpoints were highly similar between the CT-P10 and RTX groups over both treatment courses. At week 24 after the second course, mean change from week 0 of the first course in DAS28 erythrocyte sedimentation rate was −2.47 and −2.04 for CT-P10 and RTX, respectively, (p = 0.1866) and in DAS28 C-reactive protein was −2.32 and −2.00, respectively (p = 0.3268). The proportion of patients positive for antidrug antibodies at week 24 after the second treatment course was 20.0% and 21.7% in the CT-P10 and RTX groups, respectively. The safety profile of CT-P10 was comparable to that of RTX, and pharmacokinetic and pharmacodynamic properties were similar.

Conclusions

In patients with RA, efficacy, safety, and other clinical data were comparable between CT-P10 and RTX after up to two courses of treatment over 72 weeks.

(ClinicalTrials.gov identifier NCT01534884).

Electronic supplementary material

The online version of this article (doi:10.1007/s40259-017-0232-7) contains supplementary material, which is available to authorized users.

The Concept of Biosimilars: From Characterization to Evolution-A Narrative Review

Biologic agents are currently the fastest emerging segment of drug expenditure. Unlike chemically synthesized small-molecule drugs, biologics are more complex, medicinal products produced by a living organism. They have become part of the standard of care in the treatment of a large variety of diseases, such as growth disorders, autoimmune diseases, cancer, cardiovascular illnesses, hemophilia, and rare genetic conditions, to name a few. Biosimilars, which are copies of biologics that are highly similar, were introduced in the market with an aim to offer efficacy that is not clinically different from the originator or reference product, at lower prices. We aim to clarify the concept of biosimilar, from definitions, history, market entry, challenges faced, and future evolution. For that purpose, we performed a literature search on the sites of the medicines regulatory agencies and PubMed from 1990 to 2014 with the keywords "biosimilars," "market," and "regulatory." In 2006, the first biosimilar, somatropin [rDNA origin], was marketed and led the way for biosimilar drug manufacturing. As a result, manufacturers have entered a diversified competition, facing challenges in manufacturing these complex agents, such as immunogenicity and efficiency. Biosimilars are set to evolve differently in various markets, namely the U.S., Japan, the European Union, and the "pharmerging" economies.

IMPLICATIONS FOR PRACTICE

This article highlights the importance of biosimilars, as a cost-cutting strategy, in the delivery of state-of-the-art health care in developing countries, at a fraction of what a reference biological agent would cost.

B-cell-targeted therapies in relapsing forms of MS

In recent years, there has been a significant increase in the therapeutic options available for the management of relapsing forms of MS. Therapies primarily targeting B cells, including therapeutic anti-CD20 monoclonal antibodies, have been evaluated in phase I, phase II, and phase III clinical trials. Results of these trials have shown their efficacy and relatively tolerable adverse effect profiles, suggesting a favorable benefit-to-risk ratio. In this review, we discuss the pathogenic role of B cells in MS and the rationale behind the utilization of B-cell depletion as a therapeutic cellular option. We also discuss the data of clinical trials for anti-CD20 antibodies in relapsing forms of MS and existing evidence for other B-cell–directed therapeutic strategies.

Is there a reason for concern or is it just hype? - A systematic literature review of the clinical consequences of switching from originator biologics to biosimilars

INTRODUCTION

While prescribing biosimilars to patients naive to a biologic treatment is a well-accepted practice, switching clinically stable patients from an originator to a biosimilar is an issue for clinicians. Well-designed clinical trials and real-world data which study the consequences of switching from an originator biologic treatment to its biosimilar alternative are limited, especially for monoclonal antibodies. Areas covered: A systematic literature review was conducted on PubMed to identify evidence of the consequences of switching from original biologics to biosimilars. References of included papers were also scrutinized. After a title-, abstract- and full text screening, out of the 153 original hits and 77 additional ones from screening the references, 58 papers (12 empirical papers, 5 systematic reviews and 41 non-empirical papers) were included. Expert opinion: Preventing patients on biologic medicines from switching to biosimilars due to anticipated risks seems to be disproportional compared to the expected cost savings and/or improved patient access. Indeed, it is the opinion of the authors that the concern of switching to biosimilars is overhyped.

Rituximab in the treatment of follicular lymphoma: the future of biosimilars in the evolving therapeutic landscape

Follicular lymphoma (FL) is the second most common type of non-Hodgkin's lymphoma. FL is an incurable disease with treatment options ranging from a "watch-and-wait" approach to localized therapy with radiation or systemic therapy with rituximab in combination with chemotherapy regimens. This review summarizes the role of rituximab across the spectrum of FL treatment and the evolving therapeutic landscape with the emergence of novel agents currently in clinical development. Despite the prospect of new agents on the horizon, it is widely accepted that rituximab will remain as the cornerstone of therapy because of its established long-term efficacy. Many biologics, including rituximab, have lost exclusivity of composition-of-matter patent or will do so in the next few years, which is a concern for patients and physicians alike. Moreover, access to rituximab is challenging, particularly in countries with restricted resources. Together, these concerns have fueled the development of safe and effective biosimilars. The term "biosimilar" refers to a biologic product that is highly similar to an approved reference (or originator) product, notwithstanding minor differences in clinically inactive components, and for which there are no clinically meaningful differences in purity, potency, or safety. Biosimilars are developed to treat the same condition(s) using the same treatment regimens as an approved reference biologic, and have the potential to increase access to more affordable treatment of FL. Herein, we also discuss the potential benefits of eagerly awaited rituximab biosimilars, which may mitigate the impact of the lack of access to rituximab.

Biosimilars for the Treatment of Cancer: A Systematic Review of Published Evidence

Background

Biologic treatments for cancer continue to place a significant economic burden on healthcare stakeholders. Biosimilar therapies may help reduce this burden through cost savings, thereby increasing patient access.

Objectives

The purpose of this study was to collate all published data to assess the weight of available evidence (quantity and quality) for proposed monoclonal antibody biosimilars and intended copies, for the treatment of cancer.

Methods

MEDLINE^®, Embase^®, and ISI Web of Science^® databases were searched to September 2015. Conference proceedings (17) were searched (2012 to July 2015). Searches of the United States National Library of Medicine ClinicalTrials.gov registry were also conducted. Risk of bias assessments were undertaken to assess data strength and validity.

Results

Proposed biosimilars were identified in 23 studies (36 publications) in oncology and ten studies in 14 publications in oncology and chronic inflammatory diseases for bevacizumab, rituximab, and trastuzumab originators. Based on our review of the included published studies, and as inferred from the conclusions of study authors, the identified proposed biosimilars exhibit close similarity to their originators. Published data were also retrieved on intended copies of rituximab. It remains unclear what role these agents may have, as publications on rigorous clinical studies are lacking for these molecules.

Conclusion

While biosimilar products have the potential to improve patient access to important biologic therapies, robust evidence of outcomes for monoclonal antibody biosimilars in treating cancer patients, including data from comparative efficacy and safety trials, is not yet available in the published literature. Significant data gaps exist, particularly for intended copies, which reinforces the need to maintain a clear differentiation between these molecules and true biosimilars. As more biosimilars become available for use, it will be important for stakeholders to understand fully the robustness of overall evidence used to demonstrate biosimilarity and gain regulatory approval.

Electronic supplementary material

The online version of this article (doi:10.1007/s40259-016-0207-0) contains supplementary material, which is available to authorized users.

Comparability of Antibody-Mediated Cell Killing Activity Between a Proposed Biosimilar RTXM83 and the Originator Rituximab

BACKGROUND

Biosimilars are described as biological products that resemble the structure of original biologic therapeutic products, with no clinically meaningful differences in terms of safety and effectiveness from the original. A wide range of biosimilars are under development or are already licensed in many countries. Biosimilars are earning acceptance and becoming a reality for immunotherapy treatments mainly based on the alternatives for the commercial anti-CD20 monoclonal antibody rituximab. The most important mechanism of action reported for this antibody is the induction of antibody-dependent cell cytotoxicity (ADCC), which is associated with the polymorphisms present at the 158 position in the IgG receptor FcγRIIIa.

OBJECTIVE

The aim of the study was to validate the functional comparability between the proposed rituximab biosimilar RTXM83 and the original product. To achieve this we assessed the binding capacity and ADCC induction of this biosimilar, taking into account the different FcγRIIIa-158 polymorphisms.

METHODS

Binding capacity was evaluated by flow cytometry using CD20 positive cells and a wide range of antibody concentrations. The FcγRIIIa-158 polymorphisms were analyzed by polymerase chain reaction (PCR) followed by allele-specific restriction enzyme digestion. ADCC was measured by a colorimetric lactate dehydrogenase-release assay, using effector cells from donors with different FcγRIIIa-158 polymorphisms.

RESULTS

Binding capacity assay showed no differences between both products. Regarding ADCC, a similar relative potency was obtained between both antibodies, showing a higher response for the FcγRIIIa-158 valine/valine (V/V) polymorphism compared to the phenylalanine/phenylalanine (F/F), for both rituximab and RTXM83.

CONCLUSION

Our data strongly suggest the biocomparability between the proposed biosimilar and the originator rituximab, in antibody recognition and ADCC activity. Additionally, our results suggest that donors with the FcγRIIIa-158V/V polymorphism induce a higher ADCC response, as has been reported.

Monoclonal Antibody and Fusion Protein Biosimilars Across Therapeutic Areas: A Systematic Review of Published Evidence

BACKGROUND

Despite regulatory efforts to formalize guidance policies on biosimilars, there remains a need to educate healthcare stakeholders on the acknowledged definition of biosimilarity and the data that underpin it.

OBJECTIVES

The objectives of the study were to systematically collate published data for monoclonal antibodies and fusion protein biosimilars indicated for cancer, chronic inflammatory diseases, and other indications, and to explore differences in the type and weight (quantity and quality) of available evidence.

METHODS

MEDLINE, Embase, and ISI Web of Science were searched to September 2015. Conference proceedings (n = 17) were searched 2012 to July 2015. Included studies were categorized by originator, study type, and indication. To assess data strength and validity, risk of bias assessments were undertaken.

RESULTS

Across therapeutic areas, 43 named (marketed or proposed) biosimilars were identified for adalimumab, abciximab, bevacizumab, etanercept, infliximab, omalizumab, ranibizumab, rituximab, and trastuzumab originators. Infliximab CT-P13, SB2, and etanercept SB4 biosimilars have the greatest amount of published evidence of similarity with their originators, based on results of clinical studies involving larger numbers of patients or healthy subjects (N = 1405, 743, and 734, respectively). Published data were also retrieved for marketed intended copies of etanercept and rituximab.

CONCLUSIONS

This unbiased synthesis of the literature exposed significant differences in the extent of published evidence between molecules at preclinical, clinical, and post-marketing stages of development, providing clinicians and payers with a consolidated view of the available data and remaining gaps.

B Cell Therapies, Approved and Emerging: a Review of Infectious Risk and Prevention During Use

The development of B cell-targeted biologics represents a major advance in the treatment of autoimmune rheumatic diseases. As with other immunosuppressive agents, risk of infection is a key clinical concern. This review summarises safety data from 15 years of experience of rituximab in autoimmune diseases with a particular focus on opportunistic infection and class-specific complications and infection risk. Rarely, cases of progressive multifocal leucoencephalopathy in rituximab-treated patients (5/100 000) have accumulated over time although no proven causal association has yet been shown. With repeat cycles of therapy, hypogammaglobulinaemia has been observed in a larger proportion of patients and is associated with increased risk of serious infections. The infection profile of the newer B cell-targeted agent, belimumab, in patients with active systemic lupus erythematosus is also discussed. Data from registries are needed to extend insights further and also to evaluate for any impact with the difference in mode of action of belimumab and infection risk in this population.

SpeB proteolysis with imaged capillary isoelectric focusing for the characterization of domain-specific charge heterogeneities of reference and biosimilar Rituximab

The charge variations of therapeutic monoclonal antibody reveal important information of the post-translational modifications that may potentially impact the potency and safety of pharmaceutical products, especially during the evaluation of biosimilarity of therapeutic proteins. In this work, a novel SpeB-based proteolysis strategy coupling with imaged capillary isoelectric focusing was developed for the determination of domain-specific charge heterogeneities of innovator and generic Rituximab drug products from United States, European and Indian markets. It was observed that innovator Rituximab from the United States and Europe share highly similar peak distributions and charge heterogeneities with 26.2-26.6% Fc/2, 28.9-29.3% LC and 44.4-44.5% Fd peak areas detected, respectively, while multiple basic variations of Fc/2 and less acidic LC and Fd species were found from generic Rituximab from India with 20.9% Fc/2, 32.3% LC and 46.9% Fd peak areas detected. It was also demonstrated that structural changes caused by Carboxypeptidase B treatment and deamidation study at pH extremes could be sensitively captured with the established method, with the results further indicating that the generic product's basic variations of Fc/2 were un-cleaved Lysine residues, while the lack of certain acidic peaks on LC and Fd probably was due to the lower level of deamidation. This new strategy could become a useful tool to reveal domain-specific charge heterogeneities profiles of a variety of therapeutic monoclonal antibodies in regulated environments.

Biosimilars: A Multidisciplinary Perspective

A biosimilar is an officially regulated and approved copy of an originator biologic therapy. Improved affordability and consequent wider patient access compared with biologics are a significant appeal of biosimilars. Regulatory guidelines for biosimilar development and approval are rigorous and undergoing constant refinement. The process of licensing approval for all biosimilars requires demonstration of comparability in quality, efficacy, and safety between the biosimilar and reference (originator) product, which is undertaken in a stepwise procedure of nonclinical and clinical evaluation. The approval of >20 biosimilars in Europe in several drug classes, including the first monoclonal antibody biosimilar, bears testimony to the increasing regulatory acceptance of these agents. In contrast, the clinical application of biosimilars remains underrecognized by physicians across therapy areas. Therefore, this article aims to provide a comprehensive review of the biosimilar development process and to provide multidisciplinary guidance on the potential therapeutic utility of biosimilars in clinical practice. Specifically, experts discuss clinical developments in the introduction of biosimilars across the disciplines of gastroenterology, nephrology, oncology, and rheumatology, and from a payer perspective, and also highlight a common need for ongoing pharmacovigilance, robust head-to-head clinical studies, and real-world data to establish the long-term risk-benefit profile of biosimilars. In conclusion, significant potential exists for biosimilars to revolutionize biologic therapy by widening patient access across therapy areas.

Clinical and regulatory perspectives on biosimilar therapies and intended copies of biologics in rheumatology

Biologics are vital to the management of patients with rheumatic and musculoskeletal diseases such as rheumatoid arthritis and other inflammatory and autoimmune conditions. Nevertheless, access to these highly effective treatments remains an unmet medical need for many people around the world. As patents expire for existing licensed biologic (originator) products, biosimilar products can be approved by regulatory authorities and enter clinical use. Biosimilars are highly similar copies of originator biologics approved through defined and stringent regulatory processes after having undergone rigorous analytical, non-clinical, and clinical evaluations. The introduction of high-quality, safe, and effective biosimilars has the potential to expand access to these important medicines. Biosimilars are proven to be similar to the originator biologic in terms of safety and efficacy and to have no clinically meaningful differences. In contrast, “intended copies” are copies of originator biologics that have not undergone rigorous comparative evaluations according to the World Health Organization recommendations, but are being commercialized in some countries. There is a lack of information about the efficacy and safety of intended copies compared with the originator. Furthermore, they may have clinically significant differences in formulation, dosages, efficacy, or safety. In this review, we explore the differences between biosimilars and intended copies and describe key concepts related to biosimilars. Familiarity with these topics may facilitate decision making about the appropriate use of biosimilars for patients with rheumatic and musculoskeletal diseases.

The Development of a Recombinant scFv Monoclonal Antibody Targeting Canine CD20 for Use in Comparative Medicine

Monoclonal antibodies are leading agents for therapeutic treatment of human diseases, but are limited in use by the paucity of clinically relevant models for validation. Sporadic canine tumours mimic the features of some human equivalents. Developing canine immunotherapeutics can be an approach for modeling human disease responses. Rituximab is a pioneering agent used to treat human hematological malignancies. Biologic mimics that target canine CD20 are just being developed by the biotechnology industry. Towards a comparative canine-human model system, we have developed a novel anti-CD20 monoclonal antibody (NCD1.2) that binds both human and canine CD20. NCD1.2 has a sub-nanomolar K_d as defined by an octet red binding assay. Using FACS, NCD1.2 binds to clinically derived canine cells including B-cells in peripheral blood and in different histotypes of B-cell lymphoma. Immunohistochemical staining of canine tissues indicates that the NCD1.2 binds to membrane localized cells in Diffuse Large B-cell lymphoma, Marginal Zone Lymphoma, and other canine B-cell lymphomas. We cloned the heavy and light chains of NCD1.2 from hybridomas to determine whether active scaffolds can be acquired as future biologics tools. The V_H and V_L genes from the hybridomas were cloned using degenerate primers and packaged as single chains (scFv) into a phage-display library. Surprisingly, we identified two scFv (scFv-3 and scFv-7) isolated from the hybridoma with bioactivity towards CD20. The two scFv had identical V_H genes but different V_L genes and identical CDR3s, indicating that at least two light chain mRNAs are encoded by NCD1.2 hybridoma cells. Both scFv-3 and scFv-7 were cloned into mammalian vectors for secretion in CHO cells and the antibodies were bioactive towards recombinant CD20 protein or peptide. The scFv-3 and scFv-7 were cloned into an ADEPT-CPG2 bioconjugate vector where bioactivity was retained when expressed in bacterial systems. These data identify a recombinant anti-CD20 scFv that might form a useful tool for evaluation in bioconjugate-directed anti-CD20 immunotherapies in comparative medicine.

Patient attitudes and understanding about biosimilars: an international cross-sectional survey

OBJECTIVE

To understand the levels of awareness, usage, and knowledge of biosimilars among patients, caregivers, and the general population in the US and the European Union; perceptions of biosimilars compared to originator biologics; perceived benefits and drawbacks of clinical trials; and whether advocacy groups impact patients' willingness to try a biosimilar.

METHODS

An international survey was conducted which contained up to 56 closed-ended (requiring yes/no or ranking answers) and open-ended questions, depending on the population assigned. The survey was divided into distinct sections, including medication-class awareness, usage, and knowledge about biologic and biosimilar therapies; perceptions of clinical trials; and involvement in advocacy groups. Interviews were conducted in adults categorized as: 1) diagnosed: patients with inflammatory bowel disease including Crohn's disease and ulcerative colitis, rheumatoid arthritis, psoriasis, breast cancer, lung cancer, colorectal cancer, or non-Hodgkin's lymphoma; 2) diagnosed advocacy: individuals with these diseases who participated in patient support groups; 3) caregiver: has a loved one with these conditions and is involved in medical decisions; 4) general population: aged 18-64 years, without these conditions. Statistical analyses among groups within a region (US or EU) used column proportions test with a 95% confidence interval.

RESULTS

In all, 3,198 individuals responded. Awareness about biologic therapies was significantly higher in diagnosed, diagnosed advocacy, and caregiver groups (45%-78%) versus general population (27%; P<0.05). Across all groups, awareness of biosimilars was low; only 6% of the general population reported at least a general impression of biosimilars. Awareness was significantly higher in the diagnosed advocacy group (20%-30%; P<0.05). Gaps in knowledge about biosimilars included safety, efficacy, and access to these agents. Respondents had generally positive perceptions of clinical trials, although barriers to participation were identified.

CONCLUSION

An immediate need exists for patient education about biosimilars and clinical trials to ensure educated and informed decisions are made about biosimilar use.

The evolving role of biosimilars in haematology-oncology: a practical perspective

The loss of patents covering many biopharmaceutical/biological agents in the mid 1990s led to the introduction of a new generation of drugs: biosimilars. These new agents, produced by living cells just as the originator drugs, are chemically highly similar to endogenous human proteins; characterized by three-dimensionally complex, high molecular weight compounds. Among the first biosimilars used in haematology-oncology were erythropoietin and granulocyte colony-stimulating factor. After five years of use in clinical practice, the efficacy and safety profile of biosimilars approved by the European Medicines Agency is excellent. Over the next year or two, biosimilar monoclonal antibodies (MoAbs) will become available; the first will be rituximab and trastuzumab. Not only are MoAbs more complex in terms of molecular weight and number of amino acids than the first biosimilars, but they are also anticancer drugs, not merely supportive treatments like their predecessors. This opens up important questions. How are regulatory agencies to assess their clinical efficacy, immunogenicity and safety? Is the neoadjuvant clinical setting the best to evaluate them? What will regulatory agencies decide in terms of switching an originator molecule for a biosimilar or extrapolating efficacy results from one pathology to another? Once biosimilars of rituximab and trastuzumab are approved, several challenging issues will need to be addressed such as how to maintain appropriate pharmacovigilance, how to extrapolate across indications, and issues concerning automatic substitution. There is currently no consensus in any of these areas. This review addresses all these issues: new challenges that the oncology community will face in the near future.

Biosimilars in rheumatology: current perspectives and lessons learnt

Biosimilars, based on biopharmaceuticals approved by regulatory agencies that are no longer under patent protection, have efficacy and safety comparable to their reference products, and are a new therapeutic option to treat inflammatory diseases. Biosimilars must be distinguished from 'biomimics' or 'biocopies', which are marketed in some countries but have not been evaluated according to the stringent regulatory pathway used for biosimilars. CT-P13, based on infliximab, was the first biosimilar approved for the treatment of inflammatory diseases; however, some countries did not allow extrapolation of indications to all eight diseases for which the reference drug infliximab is approved. Antidrug antibodies can reduce drug levels and affect clinical efficacy, but although available data suggest that biosimilars and their reference products have comparable immunogenicity, this important property might differ between individual biopharmaceuticals. This Review discusses biosimilars already approved within the past 3 years to treat rheumatic diseases, as well as others that are currently under development. The main challenges posed by biosimilars are also addressed, such as the extrapolation of indications to diseases only studied for the reference drug, and the definition of strategies for adequate pharmacovigilance to monitor biosimilars after marketing approval.

Efficacy and safety of a biosimilar rituximab in biologic naïve patients with active rheumatoid arthritis

Biosimilar usage in rheumatology is set to increase over the next few years. This study reports the efficacy and toxicity of a rituximab biosimilar in biologic naïve patients with active rheumatoid arthritis who had inadequately responded to methotrexate. In 21 patients, over a follow-up period of 36 months, it demonstrated prolonged benefit in a majority (10 in remission with disease activity score 28 (DAS28) erythrocyte sedimentation rate (ESR) <2.6 and 9 in low disease activity state with DAS28 ESR between 3.2 and 2.6) and was well tolerated.

Barriers to the Access and Use of Rituximab in Patients with Non-Hodgkin's Lymphoma and Chronic Lymphocytic Leukemia: A Physician Survey

Biologics such as rituximab are an important component of oncology treatment strategies, although access to such therapies is challenging in countries with limited resources. This study examined access to rituximab and identified potential barriers to its use in the United States, Mexico, Turkey, Russia, and Brazil. The study also examined whether availability of a biosimilar to rituximab would improve access to, and use of, rituximab. Overall, 450 hematologists and oncologists completed a survey examining their use of rituximab in patients with non-Hodgkin’s lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Less than 40% of physicians considered rituximab as easy to access from a cost perspective. Furthermore, many physicians chose not to treat, were unable to treat, or had to modify treatment with rituximab despite guidelines recommending its use in NHL and CLL patients. Insurance coverage, reimbursement, and cost to patient were commonly reported as barriers to the use of rituximab. Across all markets, over half of physicians reported that they would increase use of rituximab if a biosimilar was available. We conclude that rituximab use would increase across all therapy types and markets if a biosimilar was available, although a biosimilar would have the greatest impact in Brazil, Mexico, and Russia.

B-cell-targeted therapies in systemic lupus erythematosus and ANCA-associated vasculitis: current progress

B cells play a central role in the pathogenesis of systemic lupus erythematosus and anti-neutrophil cytoplasmic antibody-associated vasculitis. There are various strategies for targeting B cells including depletion, inhibition of survival factors, activation and inhibition of co-stimulatory molecules. Controlled trials in systemic lupus erythematosus have shown positive results for belimumab, promising results for epratuzumab and negative results for rituximab. The failure of rituximab in controlled trials has been attributed to trial design, sample size and outcome measures rather than true inefficacy. In anti-neutrophil cytoplasmic antibody-associated vasculitis, rituximab is effective for remission induction and in relapsing disease. However, the optimal long-term re-treatment strategy remains to be determined. Over the next 5 years, evidence will be available regarding the clinical efficacy of these novel therapies, biomarkers and their long-term safety.

Target-directed development and preclinical characterization of the proposed biosimilar rituximab GP2013

Biosimilar development involves a target-directed iterative process to ensure a similar product to the originator. Here we report the preclinical development of the proposed biosimilar rituximab (GP2013). Post-translational modifications and bioactivities of GP2013 versus originator rituximab were engineered and monitored to ensure similar pharmacological profiles. Antibody-dependent cellular cytotoxicity (ADCC) was used to illustrate how different glycosylation patterns and structure–function relationships were controlled during process development. Pharmacological comparability between GP2013 and originator rituximab were confirmed in preclinical studies using clinical scale drug product. Similar in vitro ADCC potency was demonstrated when compared in a dose–response manner against two lymphoma cell lines using freshly purified human natural killer (NK) cells. In vivo efficacy was demonstrated in two well characterized mouse xenograft models, testing at sensitive sub-therapeutic dose levels. Pharmacokinetics and pharmacodynamics (CD20 cell depletion) were likewise comparable in cynomolgus monkeys. This preclinical comparability exercise confirms that GP2013 and originator rituximab are pharmacologically similar.

Potential impact of subsequent entry biologics in nephrology practice in Canada

Purpose of review

Subsequent entry biologics may soon be a reality in Canadian nephrology practice. Along with opportunities to reduce health care costs, these agents pose unique challenges that must be met for successful implementation. Understanding the experiences around the globe in both regulatory affairs and implementation will be a valuable guide for Canadian clinicians. This report provides an executive summary of the information required to guide decisions to use or implement subsequent entry biologics by comparing Canadian regulations to other developed nations, discussing their clinical issues and predicting their impact on the Canadian market and nephrology practice. We hope that this review will assist clinicians and policy makers to navigate this complex subject and to make informed decisions in the best interest of their patients.

Sources of information

Sources of information include published literature and reports available in the public domain including guidelines obtained from regulatory agencies and information shared by Pharmaceutical companies. Lastly, we generated information from our own focus group consisting of nephrologists, a regulatory body representative, a hospital formulary representative, a patient representative, a hospital administrator, and a health economist.

Findings

There exists a common and robust approach in the G20 countries for approval and regulation of subsequent entry biologics. Although by definition these agents do not have advantages (other than costs) or disadvantages compared to the original biologic, there are potential concerns and economic uncertainties regarding their implementation. Where SEBs are on the market, their market share is variable and modest.

Limitations

We did not purchase third party reports for up to the minute marketing data. Since there are no subsequent entry biologics currently on the Canadian market, the information is only predictive.

Implications

The nephrology community will have to work with patients, payers, and regulatory bodies to ensure safe and effective use of subsequent entry biologics. Cost savings can be achieved but these agents should only be used after fully understanding their unique challenges. At this time, they should not be automatically substitutable and only used for Health Canada-approved indications. Only through good pharmacovigilence will health care providers and patients become better informed.