Biosimilars: from Technical to Pharmacoeconomic Considerations

A biosimilar is a biological medicinal product claimed to be similar to a reference biological medicinal product. Its development plan includes studies comparing it with the reference product in order to confirm its similarity in terms of quality, preclinical safety, clinical efficacy, and clinical safety, including immunogenicity. Biosimilars differ from generics both in their molecular complexity and in the specific requirements that apply to them. Since patents on many biological medicinal products will expire within the next 5 years in major therapeutic areas such as oncology, rheumatology and gastroenterology and as those products are so costly to the French national health insurance system, the availability of biosimilars would have a considerable economic impact. The round table has issued a number of recommendations intended to ensure that the upcoming arrival of biosimilars on the market is a success, in which prescribing physicians would have a central role in informing and reassuring patients, an efficient monitoring of the patients treated with biologicals would be set up and time to market for biosimilars would be speeded up.     

Autologous cell therapy for cardiac repair

Importance of the field: Ever since the formation of the first biotechnology company almost three decades ago, more than 150 biopharmaceutical products have been marketed across the globe. The oldest of these biotechnology-derived products are now at the end of their patent lives, as a result of which, the development of ‘biosimilars’ is increasing.

Areas covered in the review: The review highlights aspects in which biosimilars differ from generic drugs.

What the reader will gain: The active substance of a biosimilar medicine is similar to the one of the biological reference medicine; however, biosimilars differ from generics of pharmacological drugs in aspects like size and complexity of the active substance, and the nature of the manufacturing process. The manufacture of a biopharmaceutical product is complex and involves several isolation and purification steps. These procedures are proprietary to the manufacturer of the originator product and hence even minor changes in production can have serious implications in terms of safety and efficacy of the product.

Take home message: Biosimilars should not be brought to market using the same procedure applied to generics, and existing and future regulation should prevent inappropriate and automatic substitution of a biosimilar for a reference biopharmaceutical product.     

Biosimilar biologic drugs: a new frontier in medical care

Physicians in training are expected to be aware of the newest developments in patient care. Biologic therapies have changed treatment of many diseases by specifically targeting key disease mediators, but patient access to these therapies can be limited. As patents for the first biologic therapies are expiring, the development and approval of products known as biosimilars is rapidly gaining momentum. A biosimilar is a biologic product that is highly similar to a reference product (a licensed biologic product), notwithstanding minor differences in clinically inactive components. Biosimilars undergo a thorough evaluation compared with the licensed biologic and need to demonstrate comparable clinical pharmacokinetics, efficacy, and safety including immunogenicity. Understanding the processes for new drug approvals, the rigorous evaluation of biosimilars, and considerations about their selection and use can help recently trained physicians to make informed treatment decisions and improve patient outcomes.     

Epoetin Biosimilars in Europe: Five Years On

Biosimilars have been developed for several biologic therapeutic agents, including erythropoiesis-stimulating agents (ESAs). However, biosimilars cannot be assumed to be completely identical to the reference product, nor can two different biosimilars of the same reference product be considered equivalent. Accordingly, standards for approving biosimilars are distinct from those for generic versions of conventional pharmaceuticals. By late 2007, two biosimilar epoetins (HX575 and SB309) had been approved by the European Medicines Agency (EMA), following a series of pharmacokinetic and pharmacodynamic equivalence studies, as well as phase 3 clinical comparability evaluations. Additionally, the results of a limited number of postauthorization interventional or observational studies and quality comparisons were published subsequently on both products. The reported differences in glycosylation profiles between these epoetin biosimilars and their reference product, as well as the lack of long-term safety and efficacy evaluation, could indicate a need to develop a more comprehensive analysis of the available data, and to evaluate the post-authorization real-life data, in order to gain a better understanding of any potential implications of molecular structural or formulation differences on longterm safety and effectiveness. Switching between an original reference ESA and a biosimilar (and possibly also switching between biosimilar versions of the same product) should be regarded as a change in clinical management. Clinicians need to be fully involved in such decisions. Prescribing by brand name will prevent unintentional substitution by pharmacists and allow for effective pharmacovigilance, in accordance with recent EU directives. In this review, the authors have analyzed most of the published information on the two epoetin biosimilars, HX575 and SB309, to highlight the points that healthcare providers may need to consider when assessing an epoetin biosimilar.     

Pharmacovigilance and biosimilars: considerations,needs and challenges

Introduction: Biosimilars are biologic medicines that are highly similar to approved biologics, notwithstanding minor differences in clinically inactive components. Since 2007, biosimilars have been approved for use in patients in the European Union (EU) and other regions. European experience provides several lessons as the United States (US) healthcare system prepares for biosimilar approvals. These lessons emphasize the need for adequate efficacy and safety studies, post-marketing surveys and a robust pharmacovigilance system that can accurately track and trace biologics, including biosimilars and their reference products, from the patient to the manufacturer.

Areas covered: We review the EU experience with biosimilar pharmacovigilance and discuss the implications for biosimilar pharmacovigilance in the USA. Furthermore, we review several aspects of biosimilar pharmacovigilance, including cohort event monitoring, traceability, biosimilar interchangeability, pharmacovigilance system development, nomenclature and counterfeit tracking.

Expert opinion: The availability of biosimilars as lower-cost biologics must carefully consider issues of safety, efficacy and traceability. Stringent pharmacovigilance procedures are required to detect potential differences in safety signals between biosimilars and their reference products. Pharmacovigilance of biologics should include processes that are easily used by prescribing practitioners to ensure that data are consistent and new safety signals are properly reported and assigned to the correct product.     

Implementing and Optimizing Biosimilar Use at Mayo Clinic

ObjectiveTo determine whether the formation of a multidisciplinary team, pharmacist-led therapeutic interchange, and streamlined electronic health record optimization improved biosimilar adoption throughout Mayo Clinic.Patients and MethodsThe project focused on the use of reference products and biosimilars for 5 biologics—bevacizumab, epoetin alfa, filgrastim, rituximab, and trastuzumab—at all Mayo Clinic locations. Pharmaceutical wholesale purchase histories of those reference products and biosimilars were assessed from September 1, 2020, through August 31, 2021, and compared with data from September 1, 2019, through August 31, 2020. Formulary decisions were implemented across 5 biologics for most ordering pathways on September 1, 2020. Pharmaceutical purchased drug units and expenditures were tracked at 3-month intervals for conversion to formulary-preferred contracted biosimilars.ResultsIn the final postimplementation period, the absolute percentage increase of formulary-preferred biosimilars was 69% for bevacizumab, 63% for epoetin alfa, 80% for filgrastim, 79% for rituximab, and 72% for trastuzumab. Pharmaceutical line item savings in the 12-month postimplementation period totaled $23.1 million across all 5 biologics.ConclusionCreation of a multidisciplinary team to implement formulary-preferred contracted biosimilars led to the adoption of biosimilars throughout Mayo Clinic with considerable pharmaceutical line item savings.     

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.     

Generic medicines: Greek physicians' perceptions and prescribing practices

Background and objective:  The penetration of generic drugs in the Greek pharmaceutical market is placed among the weakest in the EU. The Greek regulatory framework does not systematically support the development of this subsector and physicians are not provided with incentives for prescribing generics. The aim of this study was to investigate the prescribing profile of physicians in Greece with a focus on the factors that influence their decision on generics prescribing.
Methods:  A structured questionnaire was sent by mail to a random national sample of 1463 physicians, stratified by sex, specialty and geographical region.
Results and discussion:  The response rate was 82·3%. Greek physicians have a positive view on generics but they prefer to prescribe the original products. According to our analysis, physician's age and their opinion on generics' efficacy and effectiveness are identified as important determinants of their prescribing decision. The primary reason that could make them change their prescribing habits is the appearance of side-effects. Patients' insurance coverage and income, as well as the drug cost are also referred as factors that influence their prescribing decision. Despite the fact that they do not usually prescribe generics in their clinical practice, they are willing to substitute an original drug by a generic product.
Conclusions:  Our findings suggest that Greek physicians could be persuaded to prescribe generic medicines, if a generic promotion policy was introduced in the country. To develop such a policy, a set of supply side and demand-side measures should be implemented along with provision of information on generics to physicians during their education and clinical practice.     

Biosimilar recombinant human erythropoietins ("epoetins") and future erythropoiesis-stimulating treatments

INTRODUCTION: Recombinant human erythropoietin (rhEPO, epoetin) has prospered in the treatment of renal and chemotherapy-associated anemias. Since the patents of the original epoetins expired, biosimilars have been launched. Because these are not fully identical to the original products, non-clinical and clinical studies are necessary to show similarity with respect to quality, safety, and efficacy. AREAS COVERED: The article summarizes experiences with EU-approved biosimilar epoetins. In particular, the issue of immunogenicity is considered. Neutralizing anti-EPO antibodies can cause pure red cell aplasia (PRCA). Further, a first view is offered on future erythropoiesis-stimulating therapies. EXPERT OPINION: The term "biosimilar" should only be used for follow-on biopharmaceuticals approved under a defined regulatory pathway. The primary rationale for the therapy with biosimilars is cost saving. Two biosimilar epoetins are available in the EU that are used at the same dose(s) and dosing regimen(s) for indications of the reference product. Their advent has stimulated innovator companies to develop second-generation products with improved pharmacokinetic properties. EPO-mimicking peptides are a new therapeutic option. Other strategies focus on orally active chemical drugs that induce endogenous EPO production ("HIF stabilizers"). Epo gene transfer is also possible, but needs to be further explored with respect to efficacy and safety.     

Biosimilars: Review of current applications,obstacles, and their future in medicine

Biosimilars are a growing drug class designed to be used interchangeably with biologics. Biologics are created in living cells and are typically large, complex proteins that may have a variety of uses. Within the field of gastroenterology alone, biologics are used to treat inflammatory bowel diseases, cancers, and endocrine disorders. While biologics have proven to be effective in treating or managing many diseases, patient access is often limited by high costs. The development of biosimilars is an attempt to reduce treatment costs. Biosimilars must be nearly identical to their reference biologics in terms of efficacy, side effect risk profile, and immunogenicity. Although the manufacturing process still involves production within living cells, biosimilars undergo fewer clinical trials than do their reference biologics. This ultimately reduces the cost of production and the cost of the biosimilar drug compared to its reference biologic. Currently, seven biosimilars have been approved by the United States Food and Drug Administration (FDA) for use in Crohn’s disease, ulcerative colitis, and colorectal cancer. There are other biologics involved in treating gastroenterologic diseases for which there are no FDA approved biosimilars. Although biosimilars have the potential to reduce healthcare costs in chronic disease management, they face challenges in establishing a significant market share. Physician comfort in prescribing reference biologics instead of biosimilars and patient reluctance to switch from a biologic to a biosimilar are two common contributing factors to biosimilars’ slow increase in use. More time will be needed for biosimilars to establish a larger and more consistent market share compared to their reference biologics. Additional data confirming the safety and efficacy of biosimilars, increased number of available biosimilars, and further cost reduction of biosimilars will all be necessary to improve physician confidence in biosimilars and patient comfort with biosimilars.     

An in vitro comparison of four different immunoassays for the monitoring of Infliximab biosimilars drug levels

BackgroundSB2 (Renflexis®, Merck) and CT-P13 (Inflectra®, Pfizer) are biosimilars of the reference Infliximab (Remicade®, Janssen) and are approved in Canada for use in indications for which Infliximab is approved, including inflammatory bowel disease. These biosimilars are structurally different but exhibit comparable physicochemical characteristics, pharmaceutical effectiveness and immunogenicity compared to Infliximab. Optimal Infliximab therapy currently relies on therapeutic drug monitoring offered by several reference laboratories.ObjectiveBecause the appropriate dosing depends on accurate determination of drug levels and anti-drug antibodies, the ability of current Infliximab assays to measure the biosimilars and corresponding antibodies needs to be demonstrated.MethodsThe correlation between Infliximab and the biosimilars measured with four different enzyme-linked immunosorbent assays for Infliximab detection was evaluated. Spiked serum samples were assayed with kits from (A) Immunodiagnostik/ALPCO Diagnostics, (B) R-Biopharm, (C) Theradiag and (D) Progenika Biopharma. The impact of various concentrations of antibodies to Infliximab on the quantification of biosimilars was also tested.ResultsA good correlation of SB2, CT-P13 and reference Infliximab spiked serum samples was observed with the four assays. The observed bias between the original drug and biosimilars is clinically insignificant and less than the usual analytical variability observed with these methods. The quantification of the biosimilars and Infliximab was equally impacted in serums containing antibodies to Infliximab. The recovery of the drugs was inversely correlated with the concentration of anti-Infliximab antibodies, suggesting common immunodominant epitopes for SB2, CT-P13 and Infliximab.ConclusionThe ability of these assays to properly quantify the biosimilars Renflexis® and Inflectra® has been demonstrated. The therapeutic drug monitoring required for Infliximab therapy can be adequately performed with the biosimilars using the kits currently in use or available in clinical laboratories.     

Attitudes of Slovene general practitioners towards generic drug prescribing and comparison with international studies

BACKGROUND: Over the recent years there has been a steady 7% yearly increase in prescribing costs, which accounts for 17% of the Slovene national health care budget. Substitution of branded products by generic equivalents can offer savings. General practitioners (GPs) are often concerned about the quality of generic products and possible legal liabilities associated with their use. OBJECTIVE: We wanted to examine the attitudes of GPs in Slovenia towards generic drug prescribing. METHODS: We conducted a postal survey of a random sample of 200 out of 800 GPs in Slovenia from the National Health Insurance Institute database. GPs were asked 21 questions regarding their knowledge on generic drugs, awareness of prescribing costs, prices of generic drugs relative to brand name drugs and their attitude towards use of generic drugs. RESULTS: The 117 (58.5%) replies we received represent 15% of the GP population in Slovenia. 66.1% of GPs considered rising costs of medicines to be a serious problem for the health care budget. Each week, over 50% of GPs experienced demands from patients for specific drugs and the majority of GPs usually met their patients' demands or requests from hospital consultants for branded products. 38.3% of GPs did not take price into consideration when prescribing drugs. The majority of GPs (88.9%) perceived generics to have the same effectiveness as branded drugs. One quarter of GPs would prescribe more generics if additional clinical trials were presented. 37.3% would follow advice of academic detailers and 30.3% expected the generics to be even cheaper than they were. Independent detailing was welcomed by 63.8% of GPs because of the big influence of the pharmaceutical industry on the prescribing habits. 15.5% thought that the industry had a tremendous impact on their prescribing patterns. CONCLUSIONS: Slovene GPs are aware of the cost of prescribed drugs. They are willing to accept independent academic detailing to improve their prescribing and are willing to increase generic drugs under certain conditions.     

Current guidelines applicable for the approval of topically applied dermatological drugs in the EU

Dermatologicals as well as other medicinal products are submitted to the rules governing medicinal products in the European Union (EU) (Directive 2001/83/EC). With appreciation of the EU enlargement those regulatories deserve a recent consideration with special regard to the peculiarities of external dermatological therapy, recently passed novel and future guidelines. As regards the criteria for authorization of a medicinal product it is set out in Regulation (EEC) 2309/93 Article 11(1) that a marketing authorization shall be refused if it appears that the quality, the safety or efficacy of the medicinal product have not been adequately or sufficiently demonstrated by the applicant. Article 26(1) of Council Directive 2001/83/EC is worded a little differently but the criteria are the same irrespective of the procedure for the marketing authorization. For the final evaluation of the benefit/risk profile of a topically applied dermatological medicinal product not only the active agent but the whole galenic formulation as well has to be taken into account as the extent of penetration of the active compound might be influenced by changing the non-active substances. Furthermore the vehicle itself - independent of the active agent - influence the dermatological disorder, often in dependence on the stage of the dermatopathy. With special concern to safety/tolerability the (photo)toxic and (photo)allergic potential of the dermatological drug have to be taken into consideration too. In case of total body therapy in children the differing percutaneous resorption due to another body surface/body weight relation deserves special concern. The following review gives a survey of the current most important EU-guidelines for the evaluation of the benefit/risk profile of topically applied dermatological medicinal drugs and an outlook on further developments. As systemically applied dermatological medicinal products are assessed like other systemically applied drugs they are not treated in the following contribution.     

Biosimilars of adalimumab: the upcoming challenge in IBD

ABSTRACT

Introduction: Biosimilars represent great potential in cost saving and re-investment opportunities in healthcare and allow patients greater access to effective mAbs. Infliximab biosimilars are successfully used in all indications for whom the reference product (RP) was approved.

Areas covered: In late 2018, adalimumab biosimilars will also be available in patients with inflammatory bowel disease (IBD).

ABP501, BI 695501, GP2017, and SB5 have been approved by the EMA for the same indications of the reference product (RP, Humira®). Preclinical data show high similarity between all biosimilars and the RP. Clinical data in patients with rheumatoid arthritis and psoriasis also show no differences in terms of efficacy, safety, and immunogenicity. Data in IBD patients are still lacking.

Expert opinion: Biosimilars of adalimumab appear to be clinically equivalent to the RP. Decisions based on choosing the ideal patient to receive or to be switched to a biosimilar of adalimumab, or choosing one biosimilar vs. another, or cross-switching among biosimilars remain the next challenge in the field of IBD.     

Biosimilars: current status and future directions

Importance of the field: Expiration of patents covering biopharmaceuticals, has provided opportunities for pharmaceutical companies to develop, produce and market biosimilars or follow-on biologicals. However, there have been concerns over the degree of similarity of these complex drugs in addition to the hope that their introduction may lower the cost of such expensive medicinal products.

Areas covered in this review: The introduction/manufacturing considerations, immunogenicity and regulatory approaches to biosimilars around the world. In addition, arguments and techniques employed by pharmaceutical companies to advance or discredit biosimilar drugs will be outlined. Issues with post-marketing surveillance programmes and their limitations are described.

What the reader will gain: This evaluation outlines the controversial issues associated with introduction of biosimilar medicines across a range of pharmacological indications. Also the differences between regulatory approved medicines and biopharmaceutical products not subjected to regulatory approval (‘B-NSRA’) are highlighted. The review is limited by the rapid changes in regulatory approval and licencing of biosimilars.

Take home message: Hopefully biosimilar medicines will allow more widespread availability of expensive biopharmaceutical products. Clinicians need to be wary of non-transparent promotion of innovator/biosimilar products.     

How practitioners view generic drugs: an opinion study from general practitioners in Maine-et-Loire (France)

INTRODUCTION: Generic drugs are copies of original drugs, hence their low cost. In France, expansion of the use of generic drugs is not significant and the support of practitioners is essential in increasing this. AIM: The purpose of this study was to survey the opinion and practical experience of physicians regarding generic drugs, in order to develop a proposal for the safer use of these drugs. METHODS: A form was sent to the 1235 general and specialist practitioners in the Maine-et-Loire "département" with assistance from the regional health insurance, in March 2002. The main topics studied were prescribing practices, risks associated with generic drugs and pharmacist substitutions. The chi2 test and Fisher's exact test were used in the data analysis. RESULTS: Four hundred and twenty-nine forms were returned (34.7%). Only 55% of practitioners considered generic drugs to be as safe and effective as original drugs. Fifty-nine percent prescribe generics rarely or never. The prescribing depends on many factors, linked to the practitioner, the patient or the drug. Many practitioners reported adverse events with generic medicines. With regard to the switch by the pharmacist, it was reported that 45% of prescribers would refuse it in some instances. Among the proposals, cooperation between practitioners and pharmacists in the choice of the generic drugs was approved by 57% of physicians. DISCUSSION: The main perception is that the vastness of the generic world and the fear of adverse events are somewhat bewildering for both patients and health professionals. Among the proposals made by practitioners, a decrease in the number of generics for a same molecule and the institution of a standard price are widely approved. CONCLUSION: Practitioners do not refuse to use generic drugs but are very concerned about the risks of adverse effects for their patients. They regard it as important that a patient receiving chronic treatment be given the same generic drug each time.     

The safety of switching between therapeutic proteins

Introduction: The approval of several biosimilars in the past years has prompted discussion on potential safety risks associated with switching to and from these products. It has been suggested that switching may lead to safety concerns. However, data is limited on the clinical effects of switching.

Areas covered: In this review we provide an overview of data related to switching between human recombinant growth hormones, erythropoietins and granulocyte colony stimulating agents. We reviewed data from clinical trials, pharmacovigilance databases and an overview of the literature on the frequency of switching between these products. The review covers both switching between innovator products within the same product class and switching to and from biosimilars.

Expert opinion: Data on the frequency of switching in clinical practice is scarce, but it seems most frequent for erythropoietins. We have found no evidence from clinical trial data or post marketing surveillance data that switching to and from different biopharmaceuticals leads to safety concerns.     

Emerging role of biosimilars in the clinical care of inflammatory bowel disease patients

The increasing incidence of inflammatory bowel disease (IBD) globally has redirected the healthcare system's focus towards safe and affordable pharmacological interventions. The inception of anti-tumor necrosis factor-α (TNF-α) had resulted in a trend shift from surgical interventions. However, as the patents of approved anti-TNF-α drugs expire, biological copies of the many approved products are in the pipeline. The most commonly used biosimilar for IBD has been infliximab, followed by Adalimumab biosimilars which have been approved in major countries across the world. Although biosimilars are approved on the basis of similarity of their reference product, the lack of real-world evidence of its safety in ulcerative colitis and Crohn’s disease patients has contributed to physicians’ hesitancy. However, biosimilars are expected to reduce treatment costs and provide economic benefits.