Case studies on clinical evaluation of biosimilar monoclonal antibody: scientific considerations for regulatory approval

Multi-attribute method (MAM) to assess analytical comparability of adalimumab biosimilars

Adalimumab drug product (Humira ®), the first fully human monoclonal antibody (mAb) approved by FDA in 2002, led the top ten list of best-selling mAbs in 2018 and has been the most profitable drug in the world. With the expiration of patent protection in Europe in 2018 and in United States by 2023, the landscape is changing as up to 10 adalimumab biosimilars are expected to enter the market in the US. Biosimilars offer the potential to lower costs on health care systems and increase patient accessibility. The analytical similarity of seven different adalimumab biosimilars was accomplished in the present study using the multi-attribute method (MAM), a LC-MS based peptide mapping technique that allows for primary sequence assessment and evaluation of multiple quality attributes including deamidation, oxidation, succinimide formation, N- and C- terminal composition and detailed N-glycosylation analysis. In the first step, characterization of the most relevant post-translational modifications of a reference product was attained during the discovery phase of MAM. During the second step, as part of the MAM targeted monitoring phase, adalimumab batch-to batch variability was evaluated to define statistical intervals for the establishment of similarity ranges. The third step describes biosimilarity evaluation of predefined quality attributes and new peak detection for the assessment of any new or modified peak compared to the reference product. This study highlights a new perspective of the MAM approach and its underlying power for biotherapeutic comparability exercises in addition to analytical characterization. MAM offers a streamlined comparability assessment workflow based on high-confidence quality attribute analysis using high-resolution accurate mass mass spectrometry (HRAM MS) and the capability to detect any new or modified peak compared to the reference product.

A randomized Phase I pharmacokinetic trial comparing the potential biosimilar trastuzumab (SIBP-01) with the reference product (Herceptin®) in healthy Chinese male volunteers

OBJECTIVES

This study aimed to evaluate the bioequivalence, safety, tolerability and immunogenicity of the biosimilar trastuzumab (SIBP-01) compared to Herceptin®.

METHODS

In this Phase I randomized double-blind parallel-group trial, 100 healthy male volunteers were randomized in a1:1 ratio to receive a single 6 mg•kg-1 intravenous dose of SIBP-01 or Herceptin®. Serum concentrationswere analyzed using a validated ELISA.

RESULTS

The two groups had similar baseline characteristics. The geometric mean ratios (90% CI) of C_max, AUC_0-t and AUC_inf between the trial group and the reference group were 93.55%-104.27%, 91.98%-102.35% and 91.88%-102.34%, respectively; the geometric mean ratios (90% CI) of AUC_0-t and AUC_inf in the sensitivity analysis were 92.29%-102.63% and 91.81%-102.16%, respectively. These values were within the prespecified equivalence margins, establishing the bioequivalence of SIBP-1 and Herceptin®. AEs were similar across all subjects in the SIBP-01 and Herceptin® arms, with treatment-related AEs reported by 72.00% and 80.00%, respectively. In each group, there was one AE that caused a subject to discontinue the study.

EXPERT OPINION

Trastuzumab (Herceptin®) is significantly more effective than chemotherapy in reducing exacerbations and tumor cell growth, and its adverse events are far lower than chemotherapy. Herceptin®is very expensive for most patients in China. The protein molecular primary structure of the biosimilar trastuzumab (SIBP-01) is consistent with Herceptin®, with highly similar high level structure, biologocal activity and purity.But there are few studies comparing the bioequivalence of SIBP-01 and Herceptin® in healthy subjects and cancer patients 2.

CONCLUSIONS

This study showed the PK similarity of SIBP-01 to Herceptin®. SIBP-01 was safe and well tolerated in healthy male volunteers, with no significant differences from the reference drug in safety or immunogenicity 4.

The regulatory landscape of biosimilars: WHO efforts and progress made from 2009 to 2019

The World Health Assembly in 2014 adopted a resolution that mandates both Member States and the WHO Secretariat to facilitate access to biotherapeutic products in a way that ensures their quality, safety and efficacy. The availability of biosimilars is expected to increase access to biotherapeutic products by providing more treatment options triggering competition which would lead to a consistent reduction in the average price of treatment. Since the WHO guidelines for regulatory evaluation of biosimilars were issued in 2009, WHO has provided immense effort towards harmonizing the terminology and the regulatory framework for biosimilars globally. This article describes the progress made and the regulatory landscape changes for biosimilars in 21 countries during the past ten years. Based on the information from regulators and from publicly available data, the following has been identified: 1) WHO guidelines have contributed to setting the regulatory framework for biosimilars in countries and increasing regulatory convergence at global level; 2) terminology used for biosimilars is more consistent than in the past; 3) biosimilars are now approved in all participating countries; and 4) the dominant product class for candidate biosimilars under development is monoclonal antibodies.

WHO implementation workshop on guidelines on procedures and data requirements for changes to approved biotherapeutic products, Seoul, Republic of Korea, 25-26 June 2019

The first global workshop on implementation of the WHO guidelines on procedures and data requirements for changes to approved biotherapeutic products adopted by the WHO Expert Committee in 2018 was held in June 2019. The workshop participants recognized that the principles based on sound science and the potential for risk, as described in the WHO Guidelines on post-approval changes, which constitute the global standard for product life-cycle management are providing clarity and helping national regulatory authorities in establishing guidance while improving time-lines for an efficient regulation of products. Consequently, the regulatory situation for post-approval changes and guideline implementation is changing but there is a disparity between different countries. While the guidelines are gradually being implemented in some countries and also being considered in other countries, the need for regional workshops and further training on post-approval changes was a common theme reiterated by many participants. Given the complexities relating to post-approval changes in different regions/countries, there was a clear understanding among all participants that an efficient approach for product life-cycle management at a national level is needed to ensure faster availability of high standard, safe and efficacious medicines to patients as per the World Health Assembly Resolution 67.21.

Scientific rationale underpinning the development of biosimilar rituximab in hematological cancers and inflammatory diseases

Sandoz rituximab (SDZ-RTX; Rixathon^®; GP2013), a rituximab biosimilar, was approved in June 2017 in Europe in all indications of reference rituximab. The stepwise SDZ-RTX development program generated extensive physicochemical, structural, functional, and biological data demonstrating a match with reference rituximab on all clinically relevant attributes. A focused clinical development program followed, in two indications selected for sensitivity to detect potential differences versus reference rituximab: rheumatoid arthritis (pivotal pharmacokinetics and efficacy evaluation) and follicular lymphoma (pivotal efficacy/safety evaluation). These trials demonstrated highly similar pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity profiles. The totality of evidence for biosimilarity for SDZ-RTX, combined with knowledge that B-cell depletion is common to each approved indication, allowed SDZ-RTX approval for use in all indications of reference rituximab.

Quality assessment and its impact on clinical performance of a biosimilar erythropoietin: A simulated case study

The case study described in this paper was developed for the purpose of training for a better understanding of principles relating especially to a comprehensive evaluation of multiple quality attributes as outlined in the WHO guidelines on evaluation of similar biotherapeutic products. It is also to emphasize the importance of an understanding of the critical quality attributes and a risk assessment of the impact on clinical performance. It was prepared to mimic a real situation in which regulators need to evaluate the differences in quality attributes known to have potential impact on clinical activity. Erythropoietin has been identified as one of the important glycosylated therapeutic proteins and a good example to illustrate how structural characteristics would affect product efficacy and safety. The case study illustrates biosimilarity assessment of a candidate of erythropoietin biosimilar and the important quality attributes that need to be considered in order to understand the importance of structure-function relationships as they contribute to the stepwise evaluation of biosimilarity. This paper reflects the outcomes of the case study exercise and discussion from two WHO implementation workshops held in Ghana (September 2015) and Denmark (July 2017).

Patient Access, Unmet Medical Need, Expected Benefits, and Concerns Related to the Utilisation of Biosimilars in Eastern European Countries: A Survey of Experts

This policy research aims to map patient access barriers to biologic treatments, to explore how increased uptake of biosimilars may lower these hurdles and to identify factors limiting the increased utilisation of biosimilars. A policy survey was developed to review these questions in 10 Central and Eastern European (CEE) and Commonwealth of Independent States (CIS) countries. Two experts (one public and one private sector representative) from each country completed the survey. Questions were related to patient access, purchasing, clinical practice, and real-world data collection on both original biologics and biosimilars. Restrictions on the number of patients that can be treated and related waiting lists were reported as key patient access barriers. According to respondents, for both clinicians and payers the primary benefit of switching patients to biosimilars would be to treat more patients. However, concerns with therapeutic equivalence and fear of immunogenicity may reduce utilisation of biosimilars. Similar limitations in patient access to both original biologics and biosimilars raise concerns about the appropriateness and success of current biosimilar policies in CEE and CIS countries. The conceptual framework for additional real-world data collection exists in all countries which may provide a basis for future risk-management activities including vigorous pharmacovigilance data collection.

The state-of-play and future of antibody therapeutics

It has been over four decades since the development of monoclonal antibodies (mAbs) using a hybridoma cell line was first reported. Since then more than thirty therapeutic antibodies have been marketed, mostly as oncology, autoimmune and inflammatory therapeutics. While antibodies are very efficient, their cost-effectiveness has always been discussed owing to their high costs, accumulating to more than one billion dollars from preclinical development through to market approval. Because of this, therapeutic antibodies are inaccessible to some patients in both developed and developing countries. The growing interest in biosimilar antibodies as affordable versions of therapeutic antibodies may provide alternative treatment options as well potentially decreasing costs. As certain markets begin to capitalize on this opportunity, regulatory authorities continue to refine the requirements for demonstrating quality, efficacy and safety of biosimilar compared to originator products. In addition to biosimilars, innovations in antibody engineering are providing the opportunity to design biobetter antibodies with improved properties to maximize efficacy. Enhancing effector function, antibody drug conjugates (ADC) or targeting multiple disease pathways via multi-specific antibodies are being explored. The manufacturing process of antibodies is also moving forward with advancements relating to host cell production and purification processes. Studies into the physical and chemical degradation pathways of antibodies are contributing to the design of more stable proteins guided by computational tools. Moreover, the delivery and pharmacokinetics of antibody-based therapeutics are improving as optimized formulations are pursued through the implementation of recent innovations in the field.

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.

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.

Research and development of therapeutic mAbs: An analysis based on pipeline projects

As the subject of active research and development (R&D) in recent decades, monoclonal antibodies have emerged among the major classes of therapeutic agents for treatment of many human diseases, especially cancers, infections, and immunological disorders. This article surveys the landscape of R&D projects of therapeutic monoclonal antibodies (mAbs), which are mostly used for disease immunotherapy, from a number of perspectives, including therapeutic indications, development phases, participants, and citation of related patents. The results of this research can be used as a reference resource for pharmaceutical researchers, investors, and policymakers in the field of therapeutic mAbs.

Immunogenicity assessment of monoclonal antibody products: A simulated case study correlating antibody induction with clinical outcomes

Monoclonal antibodies are large molecules with complex structure and functions. They have a wide application for treatment of a broad range of chronic diseases and represent the largest class of biotherapeutic products. Given that biotherapeutic products may induce unwanted humoral and/or cellular immune responses in recipients, it is essential to investigate the immunogenicity of a product prior to licensure. The immune response is influenced by many factors and data generated in the pre-licensure studies are usually somewhat difficult for regulatory review. The knowledge and expertise required for this requires a thorough understanding of animal and human immunology as well as specific product characteristics, including mechanism of action, antibody assays and assessment of results in a given clinical context. The appropriate interpretation of immunogenicity data is of critical importance for defining the safety profile of a monoclonal antibody. Two case studies described in this paper were prepared to mimic a real situation in which regulators need to evaluate immunogenicity studies conducted by manufacturers of monoclonal antibody products. The specific objective of the case studies was to illustrate assessment of unwanted immunogenicity and the important factors that need to be considered in this context. Regulators and manufacturers who attended the World Health Organization (WHO) implementation workshop on Evaluation of Biotherapeutic Products, held in Seoul, Republic of Korea, in May 2014, participated in the case studies and provided valuable input. This article outlines the main aspects of immunogenicity discussed in these case studies and a summary of the lessons learned at this occasion.