Biosimilar monoclonal antibodies: the scientific basis for extrapolation

Therapeutic applications of biosimilar monoclonal antibodies: Systematic review of the efficacy, safety, and immunogenicity in autoimmune disorders

PURPOSE

Biosimilars are biological products that could be used instead of reference biological drugs to provide a less costly option for treating patients with autoimmune disorders. With the introduction of biosimilar monoclonal antibodies into the drug market, the main concern is confirming the similarity in terms of efficacy, safety, and immunogenicity of these biosimilars with their reference products. The presence of valuable comparative clinical trials to demonstrate these similarities with analytical methods is challenging. This review discusses the similarity between biosimilar mAbs and reference products as candidates for autoimmune diseases.

METHODS

Data on efficacy endpoints, adverse events, production of anti-drug antibodies (ADAs), and neutralizing antibodies (nAbs) were collected from trials.

FINDINGS

Overall, these data suggest the similarity between biosimilar mAbs and reference products in terms of safety and efficacy.

IMPLICATIONS

Biosimilars are used in a wider range of diseases, and by examining their similarities in all those diseases with reference drugs, more comprehensive results can be obtained.

Analysis of the Regulatory Science Applied to a Single Portfolio of Eight Biosimilar Product Approvals by Four Key Regulatory Authorities

Slow uptake of biosimilars in some regions is often attributed to a lack of knowledge combined with concerns about safety and efficacy. To alleviate physician and patient apprehensions, regulatory reviews from four major regulatory authorities (RAs) (European Medicines Agency, US Food and Drug Administration, Health Canada, and Japan Pharmaceuticals and Medical Devices Authority) across a portfolio of eight biosimilars were analyzed to provide insight into RA review focus and approach. RA queries were evaluated in an unbiased and systematic manner by major classification (Chemistry, Manufacturing and Controls [CMC], nonclinical, clinical or regulatory) and then via detailed sub-classification. There was a consistent, predominant focus on CMC from all RAs. The review focus based on sub-classification of clinical and regulatory queries was influenced by molecular complexity, with significant differences between categories (monoclonal antibody or protein) in the distribution of query topics; specifically, bioanalytical (p = 0.023), comparative safety and efficacy (p = 0.023), and statutory (including the justification of extrapolation) (p = 0.00033). Each biosimilar had a distinct distribution of clinical query topics, tailored to product-specific data. This analysis elucidated areas of heightened RA interest, and validated their application of regulatory science in the evaluation of biosimilar safety and efficacy.

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.

Talking to patients about biosimilars

Biologic therapies target aberrant pathways in diseases including diabetes, cancer and autoimmune disorders. Despite recent scientific advances, patient access to these agents can be limited. Biosimilars are designed to be highly similar to the originator biologic, targeting the same biological pathways, with comparable efficacy and safety. Biosimilars have the advantage of lower treatment costs, offering the potential for increased clinical use and patient access. Several biosimilars are approved for clinical use in the USA and Europe; however, there is a lack of awareness about biosimilars among healthcare providers and patients. This overview of the scientific basis of biosimilars and current indications aim to enhance discussions with patients and increase understanding of the role of biosimilars in individual treatment plans.

Update on biosimilars in inflammatory bowel disease: Position and recommendations in Mexico

The biotechnology-derived medicines known as biosimilars are defined as non-originator treatments that have demonstrated quality, efficacy, and safety comparable to the reference biologic drug. Clinical trials have shown that the infliximab biosimilar, CT-P13, and the candidates for the adalimumab biosimilars, ABP 501 and ZRC 3197, are not significantly different, with respect to efficacy and safety, from the originator drugs in patients with other autoimmune diseases. However, controversy has arisen over the use of biosimilars in inflammatory bowel disease, due to the incipient evidence not only in patients with no previous biotechnology treatment, but also in patients in remission, that could be switched to a biosimilar for non-medical reasons. The present review is the first critical analysis by different specialists in the area of gastroenterology on the use of biosimilars in inflammatory bowel disease, the evidence on interchangeability, the extrapolation of indications, efficacy, safety, immunogenicity, and the clinical impact of the Mexican health regulations. The aim of our review was to make the positioning and recommendations of these new therapeutic options known, given that they have a potential cost-benefit for both patients and healthcare institutions.

Biosimilars in oncology and inflammatory diseases: current and future considerations for clinicians in Latin America

Biological therapies have revolutionized the treatment of several cancers and systemic immune-mediated inflammatory conditions. Expiry of patents protecting a number of biologics has provided the opportunity to commercialize highly similar versions, known as biosimilars. Biosimilars are approved by regulatory agencies via an independent pathway that requires extensive head-to-head comparison with the originator product. Biosimilars have the potential to provide savings to healthcare systems and expand patient access to biologics. In Latin American countries, regulatory frameworks for biosimilar approval have been introduced in recent years, and biosimilars of monoclonal antibody and fusion protein therapies are now emerging. However, the situation in this region is complicated by the presence of "non-comparable biotherapeutics" (also known as "intended copies"), which have not been rigorously compared with the originator product. We review the considerations for clinicians in Latin American countries, focusing on monoclonal antibody biosimilars relevant to oncology, rheumatology, gastroenterology, and dermatology.

The surge in biosimilars: considerations for effective pharmacovigilance and EU regulation

The development of biosimilars is growing rapidly, especially in Europe. They are a cost-effective alternative to original biological medicines and can help improve patient access to these therapies. The European Medicines Agency (EMA) has been the first to issue scientific guidelines related to regulatory requirements for the approval of biosimilars. These guidelines have been being updated in line with advances in analytical techniques and growing experience in the clinical use of these drugs. Given the complex nature of biological medicines, they pose a greater potential risk of immunogenicity than nonbiological medicines, and hence warrant special consideration. The risk management plan for biopharmaceuticals (innovator and biosimilar drugs) should be based on strengthening ongoing pharmacovigilance activities, especially in the post-approval period. This paper addresses regulatory issues related to the approval of biosimilars in Europe associated with safety considerations linked to the development and use of these medicines. We also discuss the issues of immunogenicity, interchangeability and traceability of biological medicines.

Adaptive Seamless Design for Establishing Pharmacokinetic and Efficacy Equivalence in Developing Biosimilars

BACKGROUND

Recently, numerous pharmaceutical sponsors have expressed a great deal of interest in the development of biosimilars, which requires clinical trials to demonstrate that the pharmacokinetic (PK) and clinical efficacy are equivalent. Pharmacodynamics (PD) may be used in evaluating efficacy if there are relevant PD markers available. However, in their absence, it is necessary to design the associated clinical trials to include efficacy measures as the primary endpoint.

METHODS

In this study, we propose a novel adaptive seamless PK and efficacy design with an efficient framework to remedy the risk of misspecification of efficacy parameters and to discontinue the trial evaluating the efficacy for futility based on the PK evaluation. Here, we consider the clinical development of biosimilars including their evaluation in patients rather than healthy volunteers under a situation where both PK and efficacy parameters are required to demonstrate equivalence. The original idea of the proposed method was to organize a clinical trial that includes the statistical analysis of PK as an interim analysis, with sample size recalculation of the efficacy data.

RESULTS

Our simulation study indicated that the proposed design would allow trials to be more efficient than with the classical design.

CONCLUSIONS

This proposal provides appealing advantages, such as a shorter time period, additional cost savings, and a smaller number of patients required.

Methodological issues in the choice among different drugs approved for the same therapeutic indication: a position paper by the Italian Association of Medical Oncology (AIOM)

In oncology, as in other clinical fields, different treatments are often approved for the same therapeutic indication. In many cases, no direct comparisons are available to inform the choice in clinical practice. In 2015, the Italian Association of Medical Oncology (AIOM) instructed a working group, including both clinicians and methodologists, to discuss the issue of the best choice among different treatments available for the same indication. The working group discussed 3 different scenarios: (1) biosimilar drugs; (2) different drugs with same mechanism of action; (3) different drugs with different mechanism of action. For each scenario, methodological issues were discussed, along with the priority for investment of resources in the conduct of clinical trials testing direct comparison. As for biosimilar drugs, the panel recommended that, following comparability exercise and approval by regulatory agencies, they should be widely used, considered that their use allows financial savings. As for different drugs (with either the same or a different mechanism of action), the panel agreed that indirect comparisons and network meta-analyses are associated with relevant risk of bias and imprecision, and direct comparisons should be encouraged. The priority of these direct comparisons should be higher when the potential differences in efficacy and/or toxicity are clinically relevant. The choice of the study design (superiority vs non-inferiority) depends on the toxicity profiles and also on the presumed difference in efficacy. Scientific societies should put pressure on public bodies to identify all the administrative and financial mechanisms useful to facilitate the conduct of trials testing direct comparisons, when needed. Decision about therapeutic equivalence can have important consequences on innovation: the availability of drugs characterised by the same effectiveness, but at a lower cost, could enable non-negligible savings of economic resources that could be used to guarantee access to innovative, high-cost drugs.

Biosimilars for the Treatment of Chronic Inflammatory Diseases: A Systematic Review of Published Evidence

BACKGROUND

Clinicians are required to assimilate, critically evaluate, and extrapolate information to support appropriate use of biosimilars across indications.

OBJECTIVES

The objective of this study was to systematically collate all published data in order to assess the weight (quantity and quality) of available evidence for each molecule and inform and support healthcare decision-making in chronic inflammatory diseases.

METHODS

MEDLINE®, EMBASE®, and ISI Web of Science® were searched to September 2015. Selected conference proceedings were searched from 2012 to July 2015. Studies disclosing biosimilars with unique identifiers were categorized by originator, study type, and indication. Risk of bias assessments were performed. Intended copies were differentiated as commercially available agents without evidence of rigorous comparative biosimilarity evaluations.

RESULTS

Proposed biosimilars for adalimumab, etanercept, infliximab, and rituximab are reported in the published literature. Across indications, approved biosimilars infliximab CT-P13, SB2, and etanercept SB4 have published studies involving the largest number of patients or healthy subjects (n = 1405, 743, and 734, respectively), mostly in rheumatoid arthritis. At data cut-off, only CT-P13 had published data in ankylosing spondylitis (n = 250; randomized control trial) and ulcerative colitis/Crohn's disease (n = 336; observational studies). Published data were not available for ongoing studies in psoriasis patients. Four intended copies were identified in published studies (total: n = 1430; n = 1372 in observational studies). Thematic analysis of non-empirical publications showed that indication extrapolation remains an issue, particularly for gastroenterologists.

CONCLUSIONS

While most agents display a moderate to high degree of similarity to their originator in the published studies identified, large discrepancies persist in the overall amount and type of data available in the public domain. Significant gaps exist particularly for intended copies, reinforcing the need to maintain a clear differentiation between these molecules and true biosimilars.

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.

Controversies in Establishing Biosimilarity: Extrapolation of Indications and Global Labeling Practices

The principles of establishing biosimilarity are to demonstrate structural and functional similarity to a reference product using the most discriminatory analytical methods. There is still considerable controversy on the scientific basis for extrapolation of indications for biosimilars, which has been strengthened by diverging global regulatory decision making. Closely related to the question of extrapolation is the question of how to communicate the evidence base for authorizing biosimilars to healthcare professionals. In this paper we will consider some of the discussions around extrapolation of indications and the implications of decisions of various regulatory agencies in the world regarding the authorization and labeling of biosimilars.

Advanced assessment of the physicochemical characteristics of Remicade® and Inflectra® by sensitive LC/MS techniques

In this study, we demonstrate the utility of ultra-performance liquid chromatography coupled to mass spectrometry (MS) and ion-mobility spectrometry (IMS) to characterize and compare reference and biosimilar monoclonal antibodies (mAbs) at an advanced level. Specifically, we focus on infliximab and compared the glycan profiles, higher order structures, and their host cell proteins (HCPs) of the reference and biosimilar products, which have the brand names Remicade® and Inflectra®, respectively. Overall, the biosimilar attributes mirrored those of the reference product to a very high degree. The glycan profiling analysis demonstrated a high degree of similarity, especially among the higher abundance glycans. Some differences were observed for the lower abundance glycans. Glycans terminated with N-glycolylneuraminic acid were generally observed to be at higher normalized abundance levels on the biosimilar mAb, while those possessing α-linked galactose pairs were more often expressed at higher levels on the reference molecule. Hydrogen deuterium exchange (HDX) analyses further confirmed the higher-order similarity of the 2 molecules. These results demonstrated only very slight differences between the 2 products, which, interestingly, seemed to be in the area where the N-linked glycans reside. The HCP analysis by a 2D-UPLC IMS-MS approach revealed that the same 2 HCPs were present in both mAb samples. Our ability to perform these types of analyses and acquire insightful data for biosimilarity assessment is based upon our highly sensitive UPLC MS and IMS methods.