Biosimilar granulocyte-colony-stimulating factor for healthy donor stem cell mobilization: need we be afraid?

Biosimilars are approved biologics with comparable quality, safety, and efficacy to a reference product. Unlike generics, which are chemically manufactured copies of small-molecule drugs with relatively simple chemical structures, the biosimilar designation is applied to drugs that are produced by living organisms, implying much more difficult to control manufacturing and purification procedures. To account for these complexities, the European Medicines Agency (EMA), the US Food and Drug Administration, the Australian Therapeutic Goods Administration, and other regulatory authorities have devised and implemented specific, markedly more demanding pathways for the evaluation and approval of biosimilars. To date, several biosimilars have been approved, including versions of somatropin, erythropoietin, and granulocyte-colony-stimulating factor (G-CSF), and several biosimilar monoclonal antibodies are currently in development. The reference G-CSF product (Neupogen, Amgen) has been used for many years for prevention and treatment of neutropenia and also for mobilization of peripheral blood stem cells (PBSCs). However, concerns have been raised about the safety and efficacy of biosimilar G-CSF during PBSC mobilization procedures, especially in healthy donors. This article reviews the available evidence on the use of biosimilar G-CSF in this setting. Aggregate clinical evidence supports the assessment by the EMA of biosimilar and originator G-CSF as highly biologically similar, with respect to desired and undesired effects.

[What are biosimilars and what do they bring to us?]

Biosimilar medicines are a new category of medicinal products that substantially differ from generic preparations through the necessary submission of conclusive evidence of their therapeutic efficacy and therefore it is not sufficient to merely state their biological equivalence. Apart from the proven efficacy, also their safety is evaluated of course, with an emphasis on immunogenicity regarding biological nature of these substances. As a result, requirements for registration are much stricter. With regard to the current boom of the preparations labelled in a simplified way as biological or specifically targeted drugs, we can certainly expect a growing number of newly registered medicinal products in this category in the near future. Last year, a biosimilar insulin analogue of glargine was approved for administration at the level of the European Medicines Agency (EMA) in accordance with the aforementioned procedures; its efficacy and safety profile have been found within the registration studies practically identical, or non-inferior, to the original insulin analogue.

The Legal and Regulatory Status of Biosimilars: How Product Naming and State Substitution Laws May Impact the United States Healthcare System

Alongside the constitutional controversy ultimately addressed by the Supreme Court, the colossal Patient Protection and Affordable Care Act (ACA) ushered in a new paradigm for regulation of biologics by the Food and Drug Administration (FDA). Nestled within the expansive ACA, the Biologics Price Competition and Innovation Act (BPCIA) set forth an abbreviated pathway to market for "biosimilar" and "interchangeable" biological products. While the current BPCIA implementation debate focuses chiefly on the scope of scientific and technical assessments by the FDA and the effect on the emergent biosimilar industry, two issues will prove essential for determinations of access to and costs of the resulting products: how the biosimilar and interchangeable biosimilar biologics are to be named, and whether pharmacist substitution is appropriate for products the FDA deems interchangeable. This article examines the current debate surrounding the use of nonproprietary names for biosimilar biologics, as well as state efforts to reconcile automatic substitution laws for the eventual products. In particular, the article addresses the implications for patients and the United States health care system, highlighting the potential negative effect on anticipated cost-savings, hindrances for effective tracking and reporting of adverse events, and a general lack of consistency in state laws.

Biologic Drugs, Biosimilars, and Barriers to Entry

Biologic drugs represent an important new category of drugs in the effort to improve health outcomes in this country. Yet, these cutting-edge drugs are often cost prohibitive, preventing access for many Americans. Recognizing the need for more affordable, generic substitutes for biologic drugs—or biosimilars—Congress recently created a biosimilars approval pathway that would enable these cheaper biologic drugs to obtain FDA approval and reach patients more quickly. Unfortunately, original biologics manufacturers have sought to extend their current monopoly profits by erecting various legal and regulatory barriers to entry. Their legal maneuvers take many forms, from delaying approval of safe biosimilars to abrogating previous commitments to international drug-naming protocols, and even circumventing Congressional intent for biosimilar substitution. Regrettably, these policies reduce competition in the market for biologic drugs, impede drug innovation, increase drug costs, and limit patient access to these important medications. This article explores the conflict between biologics and biosimilars, and the consequences that barriers to biosimilar entry in this market will create.

Biosimilars: the process is the product. The example of recombinant streptokinase

BACKGROUND

Worldwide, streptokinase remains the most used thrombolytic agent for the treatment of myocardial infarction. Recombinant streptokinase, from E. coli, is increasingly used in developing countries as a biosimilar of native streptokinase; however, potency assignments relative to the WHO International Standard (IS) are highly variable with potentially dangerous consequences. A proportion of recombinant streptokinase appears to be incompletely processed, retaining the amino-terminal methionine engineered for intracellular expression.

OBJECTIVES

To investigate and quantify the impact of an amino-terminal methionine on streptokinase activity.

METHODS

Mature native streptokinase (rSK) was cloned and a novel variant constructed to include an amino-terminal methionine (rSK-Met) that is not susceptible to processing during expression. Potencies of rSK and rSK-Met were determined relative to the WHO IS using a chromogenic solution (European Pharmacopoeia) assay, and fibrin-based assays.

RESULTS

In the chromogenic solution assay there was no measurable difference between rSK and rSK-Met activities. In the fibrin-based methods, however, potency estimates for rSK-Met were greatly reduced compared with rSK, and fibrinolytic activity for rSK-Met was shown to increase over time with methionine aminopeptidase treatment. This apparent difference in activity and fibrin selectivity was consistent with potency estimates for several different batches of commercial recombinant streptokinase products also tested; consequently, different potencies would be assigned to therapeutic recombinant streptokinase products depending on the degree of amino-terminal methionine processing, and on the pharmacopoeial assay method used, affecting the dosage patients receive. This has serious health implications and provides an example of the danger in the unregulated clinical use of biosimilars.

[Current situations and the future prospect of monoclonal antibody products]

Monoclonal antibody products and monoclonal antibody-based biopharmaceuticals have shown considerable effectiveness in the treatment for variety of diseases; cancer, auto-immune/auto-inflammation diseases and so on. Significant advance in monoclonal antibody products for cancer treatments was made with antibody-drug conjugates (ADC), and antibodies for blockade of immune checkpoints. Already 3 ADCs and 2 anti-immune-checkpoint antibodies products have been approved, and these monoclonal antibody-related product pipelines reach over 30. On the other hand, EU approved first monoclonal-antibody biosimilar, RemsimaTM (infliximab), suggesting that other monoclonal-antibody biosmilars will follow to the market. In this paper, several new issues about monoclonal antibody products will be discussed.

Risk-based Process Development of Biosimilars as Part of the Quality by Design Paradigm

In the last few years, several quality by design (QbD) studies demonstrated the benefit of systematic approaches for biopharmaceutical development. However, only very few studies identified biosimilars as a special case of product development. The targeted quality profile of biosimilars is strictly defined by the originator's product characteristic. Moreover, the major source of prior knowledge is the experience with the originator product itself. Processing this information in biosimilar development has a major effect on risk management and process development strategies. The main objective of this contribution is to demonstrate how risk management can facilitate the implementation of QbD in early-stage product development with special emphasis on fitting the reported approaches to biosimilars. Risk assessments were highlighted as important tools to integrate prior knowledge in biosimilar development. The risk assessment process as suggested by the International Conference on Harmonization (ICH Q9) was reviewed and three elements were identified to play a key role in targeted risk assessment approaches: proper understanding of target linkage, risk assessment tool compliance, and criticality threshold value. Adjusting these steps to biosimilar applications helped to address some unique challenges of these products such as a strictly defined quality profile or a lack of process knowledge. This contribution demonstrates the need for tailored risk management approaches for the risk-based development of biosimilars and provides novel tools for the integration of additional knowledge available for these products.

LAY ABSTRACT

The pharmaceutical industry is facing challenges such as profit loss and price competition. Companies are forced to rationalize business models and to cut costs in development as well as manufacturing. These trends recently hinder the implementation of any concepts that do not offer certain financial benefit or promise a long return of investment. Quality by design (QbD) is a concept that is currently struggling for more acceptance from the side of the pharmaceutical industry. To achieve this, the major goals of QbD have to be revisited and QbD tools have to be subsequently developed. This contribution offers an example as to how implement risk management in early-stage biosimilar development as part of the QbD concept. The main goal was to go beyond the conventional QbD workflow and to adjust risk management to the challenges of biosimilar products. Accordingly, instead of using methods like failure mode and effects analysis, recommendations of the ICH Q9 guideline were reviewed and put into practice by creating tailored risk assessment tools. The novelty of this contribution is to report those tailored tools ready-to-use for early bioprocess development of biosimilars along QbD principles.

Initial steps in the regulation of generic biological drugs: a comparison of U.S. and Canadian regimes

Biological drug products are poised to overtake traditional pharmaceuticals as the best selling products in the pharmaceutical industry. Accordingly, both innovator and generic drug companies have a vested interest in the rules and regulations governing the approval and market entry of follow-on ("generic") biologic drug products as well as relevant procedures for litigating disputes involving biologic drug products. The U.S. and Canada both regulate the development and sale of traditional generic drugs through complex legal and regulatory schemes that seek to maintain a balance of interests between the innovator and generic sectors of the pharmaceutical industry. With the continued emergence of biological drugs, both countries have recently set forth legal and regulatory schemes to address the unique issues presented by generic biologic drug products. These issues include the requirements needed to submit an application for a generic biologic; biosimilarity vs. interchangeability designations; market and data exclusivity; and procedures for litigating disputes involving biologic drugs. Like the respective rules governing traditional pharmaceuticals, the recent U.S. and Canadian regulations addressing biological drugs contain both similarities and differences. As such, an understanding of both countries regulatory schemes will help both innovators and generics in decision making and legal strategy related to biological drugs. This article provides a comparative overview of the two systems to assist in such an understanding.