Review of Biosimilar Trials and Data on Etanercept in Rheumatoid Arthritis

PURPOSE OF REVIEW

Etanercept was the first tumour necrosis factor inhibitor approved to treat rheumatoid arthritis (RA) in the United States (US) and Europe. The recent patent expiration of the etanercept originator ENBREL in Europe has facilitated the development of biosimilar products, creating the prospect of reduced treatment costs. In this article, we review the original trials for etanercept in RA to facilitate critical appraisal of biosimilar trial data.

RECENT FINDINGS

Two etanercept biosimilars are currently approved in Europe and/or the US, SB4 (Benepali) and GP2015 (Erelzi), having met the pre-specified equivalence criteria for biosimilarity. Trial data demonstrates subtle differences in clinical outcomes and adverse events between the biosimilars and the reference product (RP). The development of etanercept biosimilars may reduce the financial burden of treating RA, but real-world data regarding efficacy and safety in comparison to the RP will be vital to assess for meaningful differences.

Anti-tumor necrosis factor biosimilars and intended copies in rheumatology: Perspective from the Asia Pacific region

Although anti-tumor necrosis factor (TNF) agents have greatly improved the management of rheumatic diseases, their cost limits access to many patients throughout the world. As a result, patients and clinicians have turned to biosimilars to provide similar efficacy at a lower cost. Many of the regulatory guidelines in the Asia Pacific region are largely based on those of the European Medicines Agency and the World Health Organization; however, there are variations between countries. Additionally, in some countries, intended copies are available that were approved prior to the development of guidelines and have not fulfilled the requirements of a biosimilar. We review the various regulatory requirements for biosimilars in the Asia Pacific region, the anti-TNF biosimilars and intended copies approved in the region, and whether clinical data are available for these agents. We discuss concerns about the need for additional regulations and education, and we provide recommendations for a multidisciplinary pharmacovigilance approach that closely monitors the safety of biosimilar use.

Focus on biosimilar etanercept - bioequivalence and interchangeability

BACKGROUND

The recent approval of reference etanercept (re-ETN) biosimilars SB4, GP2015, and HD203 produced relevant changes in the management of rheumatoid arthritis (RA), psoriatic arthritis, and ankylosing spondylitis due to the considerably lower cost of these products and the consequent savings.

AIMS

To review the pharmacodynamics, pharmacokinetics, efficacy, and safety of ETN biosimilars when employed as first-line therapy or after transition from re-ETN. Patients' acceptability was also addressed.

EVIDENCE REVIEW

The available literature was reviewed through a search of PubMed database, and abstract books of the American College for Rheumatology and European League Against Rheumatism annual meetings. SB4, GP2015, and HD203 were licensed by the US, European and South Korea regulatory agencies after the bioequivalence to re-ETN was demonstrated through pharmacodynamic and pharmacokinetic studies, and randomized, head to head, controlled trials. Based on the evidence of efficacy and safety of SB4 and HD203 in RA, and of GP2015 in psoriasis, by the extrapolation principle, the three biosimilars were approved for all indications licensed for re-ETN, and the regulatory agencies introduced the interchangeability from the originator to the biosimilar. Extrapolation of indications, and particularly interchangeability raised relevant concerns among the rheumatologists due to the low level of evidence supporting the switching strategy (or transition). Rheumatologists' concerns are oriented toward the relevant number of biosimilar discontinuations after the transition ranging from 7%-17% over a short-term follow-up period. As resulted from two studies, at least 20%-30% of the patients claimed more exhaustive information on the switching procedure.

CONCLUSION

Based on the available evidence, re-ETN biosimilars may be a good option as first-line therapy, while further data are needed to definitively establish the efficacy, safety, and the economic reflexes of transitioning from re-ETN.

Consensus-based recommendations for the use of biosimilars to treat rheumatological diseases

The study aimed to develop evidence-based recommendations regarding the evaluation and use of biosimilars to treat rheumatological diseases. The task force comprised an expert group of specialists in rheumatology, dermatology and gastroenterology, and pharmacologists, patients and a regulator from ten countries. Four key topics regarding biosimilars were identified through a process of discussion and consensus. Using a Delphi process, specific questions were then formulated to guide a systematic literature review. Relevant English-language publications through November 2016 were searched systematically for each topic using Medline; selected papers and pertinent reviews were examined for additional relevant references; and abstracts presented at the 2015 and 2016 American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) annual scientific meetings were searched for those about biosimilars. The experts used evidence obtained from these studies to develop a set of overarching principles and consensus recommendations. The level of evidence and grade of recommendation were determined for each. By the search strategy, 490 references were identified. Of these, 29 full-text papers were included in the systematic review. Additionally, 20 abstracts were retrieved from the ACR and EULAR conference abstract databases. Five overarching principles and eight consensus recommendations were generated, encompassing considerations regarding clinical trials, immunogenicity, extrapolation of indications, switching between bio-originators and biosimilars and among biosimilars, and cost. The level of evidence and grade of recommendation for each varied according to available published evidence. Five overarching principles and eight consensus recommendations regarding the evaluation and use of biosimilars to treat rheumatological diseases were developed using research-based evidence and expert opinion.

[Revised version of the statement by the DGRh on biosimilars-update 2017]

The treatment of rheumatic diseases with bioloics has significantly improved the prognosis of patients. Currently, there are 13 preparations available in Germany for the treatment of patients with inflammatory rheumatic diseases. These original preparations generally have-depending on the individual country-15 years of patent protection. As soon as the patent has expired, approved biosimilars can be brought into use. For the approval of a biosimilar, authorities such as the European Medical Agency or the American Food and Drug Administration require proof of the best possible comparability with respect to efficacy and safety in comparison to the original or reference product. Since 2015, biosimilars of inifliximab, adalimumab, etanercept and rituximab have been granted approval in the European Union, the USA, Japan and in other countries. Further biosimilar products for these reference products are in development for treatment in rheumatology. From a societal and medical point of view, this opens up the possibility to increase the availability of biopharmaceutical products for patients through lower prices. In Germany, this possibility has already occurred-statutory health insurance physicians have introduced quotas for biosimilars, which will ultimately decrease spending and healthcare costs. This can lead to price reductions of the original products, which has already happened in Germany. Biosimilars can be prescribed for new patients or as a change from the original to the generic drug. When switching, a distinction is made between individual switching (interchangeability), which is made in individual consultation between the physician and the patient, and nonmedical switching (substitution) made at the societal or governmental level, which is made in the context of health care cost containment, and then, for example, implemented at the pharmacy level. Preliminary data from Norway and Denmark are available for substitution on the basis of results from large studies or registries in which systematic changes were made. The previous conclusion was that this does not lead to new problems for the patients. The German Society for Rheumatology recognizes the advantages of introducing biosimilars in Germany, but recommends that their use be based primarily on a joint decision by the treating physician and patient.

Biosimilars in Dermatology - theory becomes reality

Biosimilars are biological medicines that are analogues of a specific reference product. Biosimilars of the tumor necrosis factor alpha inhibitors infliximab and etanercept are already approved and available for dermatological indications. Regulatory agencies require in-depth analysis of physicochemical and functional properties of these highly complex molecules as well as clinical data on their similarity regarding efficacy and safety in at least one clinical trial in a sensitive and homogeneous population. Thus, it must be shown that biosimilars are essentially the same as the originator product if they are to be licensed in regulated drug markets. As a consequence, these data are extrapolated from one molecule (the originator) to another (biosimilar) resulting in an approval that includes the same indications as the originator product. While extrapolation is well accepted and regulated, clear recommendations regarding the interchangeability of originators and biosimilars as well as data on multiple consecutive switching are missing. Current scientific knowledge does not argue against the use of biosimilars for dermatological indications, but sequential switching of biosimilars should be considered carefully. To increase confidence and enhance evidence for biosimilars, accurate documentation of the specific products given to each patient is essential and should preferably be included in patient registries.

Variability of intended copies for etanercept (Enbrel®): Data on multiple batches of seven products

Fusion protein and monoclonal antibody-based tumor necrosis factor (TNF) inhibitors represent established treatment options for a range of inflammatory diseases. Regulatory authorities have outlined the structural characterization and clinical assessments necessary to establish biosimilarity of a new biotherapeutic product with the innovator biologic drug. Biologic products that would not meet the minimum World Health Organization's standard for evaluation of similar biotherapeutic products are available in some countries; in some cases relevant data to assess biosimilarity and appropriate regulatory approval pathways are lacking. Batches of seven intended copy (IC) products for etanercept (Enbrel®) were subjected to a subset of test methods used in the routine release and heightened characterization of Enbrel®, to determine key attributes of identity, quality, purity, strength, and activity. While a number of quality attributes of the IC lots tested met the release specifications for Enbrel®, none fell within these limits across all methods performed, and there were no IC lots that satisfied the criteria typically applied by the innovator to support comparability with Enbrel®. Although the consequences of these differences are largely unknown, the potential for unanticipated clinical outcomes should not be overlooked.

Biosimilars: implications for rheumatoid arthritis therapy

PURPOSE OF REVIEW

Abbreviated pathways for the approval of biosimilars have been established in the European Union (EU), the United States, and other countries. Biosimilar TNF inhibitors have been available in South Korea and the EU since 2012 and 2013, respectively, and the first biosimilar infliximab was introduced to the clinic in the United States in November 2016. Five TNF inhibitor biosimilars have now been approved, and many other biosimilars to treat rheumatoid arthritis and other inflammatory diseases are in development.

RECENT FINDINGS

Over the last 18 months, published results of randomized clinical trials (RCTs) have shown equivalent efficacy and comparable safety and immunogenicity of biosimilars with their reference products. 'Real world' experience with biosimilars in the EU continues to increase and provides evidence regarding the efficacy and safety of using biosimilars in the clinic and of switching from bio-originators to their biosimilars.

SUMMARY

Cost implications of using biosimilars and extrapolation of their use to treat diseases in which they were not tested in RCTs are of great interest. We review the results of RCTs and available experience with biosimilars in the clinic.

Switching Between Reference Biologics and Biosimilars for the Treatment of Rheumatology, Gastroenterology, and Dermatology Inflammatory Conditions: Considerations for the Clinician

PURPOSE OF REVIEW

Biosimilars of the reference biologic therapeutics infliximab, etanercept, adalimumab, and rituximab are entering the market. Clinical and real-world data on the effects of reference → biosimilar switching are limited. This review was carried out to assess the current body of switching data.

RECENT FINDINGS

Fifty-three switching studies were identified. Infliximab publications covered CT-P13 (25 studies), SB2 (1), infliximab NK (1), and unspecified infliximab biosimilars (2). Etanercept publications covered SB4 (2) and GP2015 (2). Adalimumab publications covered ABP 501 (2) and SB5 (1). Rituximab publications covered CT-P10 (1). Efficacy and safety data generally showed no differences between patients who switched treatments versus those who did not. No differences were seen pre- and post-switch. Immunogenicity data were presented in 19/37 (51%) studies. Additional data from switching studies of these therapies are still required, as is continuing pharma-covigilance. Switching should remain a case-by-case clinical decision made by the physician and patient on an individual basis supported by scientific evidence.

Efficacy, safety and pharmacokinetics of biosimilars of anti-tumor necrosis factor-α agents in rheumatic diseases; A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of biosimilars of anti-tumor necrosis factor (TNF)-α agents compared to their reference agents in immune mediated diseases.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) assessing the efficacy and safety of biosimilars of anti-TNF-α agents compared to their reference agents in patients with various immune mediated diseases. The outcomes were the rates of clinical response and adverse events among patients treated with biosimilars compared to their reference agents. Additionally, occurrence of anti-drug antibodies with the use of biosimilars was compared to the reference agents.

RESULTS

Nine studies reporting outcomes in 3291 patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) were identified (5 infliximab, 2 adalimumab, and 2 etanercept). No RCTs in other diseases were found. Biosimilars of infliximab showed similar rates of clinical response compared to the reference agent in RA and AS. Frequency of anti-drug antibody and adverse events were similar except for a slightly, but significantly, higher risk of upper respiratory tract infections with biosimilar (RR 1.54, P = 0.047, 95% confidence interval (CI) = 1.01-2.37). Biosimilar of adalimumab showed no differences among any outcomes compared to the reference agent. Biosimilars of etanercept showed no differences for clinical response and frequency of adverse events, but showed a significantly lower rate of anti-drug antibodies at 24-30 weeks (RR 0.05, P <0.0001%, 95% CI = 0.01-0.21).

CONCLUSION

In the present study, biosimilars of anti-TNF-α agents had an overall comparable efficacy and safety profile compared to their reference agents in RA and AS supporting their use for these conditions.

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.

A Randomized, Phase I Pharmacokinetic Study Comparing SB2 and Infliximab Reference Product (Remicade(®)) in Healthy Subjects

OBJECTIVE

SB2, a biosimilar to infliximab reference product (INF), has an identical amino acid sequence and similar physicochemical functional properties to its reference product. The primary objective of this study is to demonstrate pharmacokinetic (PK) bioequivalence between SB2 and EU-sourced INF (EU-INF), between SB2 and US-sourced INF (US-INF), and between EU-INF and US-INF.

METHODS

This study was a randomized, single-blind, three-arm, parallel group study in 159 healthy subjects. All subjects received a single 5 mg/kg intravenous infusion of study drug and then were observed for 10 weeks to study PK, safety and immunogenicity. The primary PK parameters were area under the concentration-time curve (AUC) from time zero to infinity (AUCinf), AUC from time zero to the last quantifiable concentration (AUClast) and maximum concentration (C max). Bioequivalence for the primary PK parameters was to be concluded using an analysis of variance (ANOVA) if the 90 % confidence intervals (CIs) for the ratio of geometric least squares means (LSMeans) of the treatments compared were completely contained within the pre-defined equivalence margin, 0.8-1.25.

RESULTS

All of the 90 % CIs for the geometric LSMean ratios of primary PK parameters for each comparison were within the pre-defined equivalence margin. The proportion of subjects who experienced treatment-emergent adverse events was comparable between treatments. The incidences of anti-drug antibodies between the three treatments were comparable.

CONCLUSION

This study demonstrated biosimilarity of SB2 to its marketed reference products of infliximab in terms of PK equivalence in healthy subjects. SB2 was generally well tolerated and showed comparable safety and immunogenicity profiles to the reference products (ClinicalTrials.gov Identifier: NCT01922336).

A randomized phase l pharmacokinetic study comparing SB4 and etanercept reference product (Enbrel®) in healthy subjects

Aims

SB4 has been developed as a biosimilar of etanercept. The primary objective of the present study was to demonstrate the pharmacokinetic (PK) equivalence between SB4 and European Union ‐sourced etanercept (EU‐ETN), SB4 and United States‐sourced etanercept (US‐ETN), and EU‐ETN and US‐ETN. The safety and immunogenicity were also compared between the treatments.

Methods

This was a single‐blind, three‐part, crossover study in 138 healthy male subjects. In each part, 46 subjects were randomized at a 1:1 ratio to receive a single 50 mg subcutaneous dose of the treatments (part A: SB4 or EU‐ETN; part B: SB4 or US‐ETN; and part C: EU‐ETN or US‐ETN) in period 1, followed by the crossover treatment in period 2 according to their assigned sequences. PK equivalence between the treatments was determined using the standard equivalence margin of 80–125%.

Results

The geometric least squares means ratios of AUC_inf, AUC_last and C_max were 99.04%, 98.62% and 103.71% (part A: SB4 vs. EU‐ETN); 101.09%, 100.96% and 104.36% (part B: SB4 vs. US‐ETN); and 100.51%, 101.27% and 103.29% (part C: EU‐ETN vs. US‐ETN), respectively, and the corresponding 90% confidence intervals were completely contained within the limits of 80–125 %. The incidence of treatment‐emergent adverse events was comparable, and the incidence of the antidrug antibodies was lower in SB4 compared with the reference products.

Conclusions

The present study demonstrated PK equivalence between SB4 and EU‐ETN, SB4 and US‐ETN, and EU‐ETN and US‐ETN in healthy male subjects. SB4 was well tolerated, with a lower immunogenicity profile and similar safety profile compared with those of the reference products.

A phase III, multicentre, randomised, double-blind, active-controlled, parallel-group trial comparing safety and efficacy of HD203, with innovator etanercept, in combination with methotrexate, in patients with rheumatoid arthritis: the HERA study

Objectives

To evaluate equivalence in efficacy for rheumatoid arthritis (RA) and compare the safety of the biosimilar HD203 with innovator etanercept (ETN) plus methotrexate (MTX) (ClinicalTrials.govNCT01270997).

Methods

Patients with active RA received 25 mg HD203 or ETN subcutaneously twice-weekly with MTX for 48 weeks in a phase III, multicentre, randomised, double-blind, parallel-group design. The primary end point was the proportion of patients achieving the American College of Rheumatology 20% response (ACR20) at week 24 for per-protocol study completer set (PPS). Secondary end points included ACR response criteria, ACRn, European League against Rheumatism (EULAR) response, change in Disease Activity Score 28 (DAS28), patient-reported outcomes, safety and immunogenicity.

Results

Of the 294 randomised patients (HD203, n=147; ETN, n=147), 233 comprised the 24-week PPS (n=115 and 118, respectively). ACR20 at week 24 was achieved by 83.48% and 81.36% of PPS patients, respectively, demonstrating equivalent efficacy within predefined margins of ±20% (treatment difference 2.12%, 95% CI −7.65% to 11.89%). Outcomes for secondary end points were consistent with the primary efficacy findings. Groups were comparable for overall incidences of treatment-emergent (all-causality) adverse events (AEs) (HD203 113 (76.9%) vs ETN 114 (78.1%) (p=0.804)), adverse drug reactions, serious AEs and discontinuations due to AEs. Few patients (HD203, n=8; ETN, n=3) tested positive for anti-drug antibodies.

Conclusion

The study met the primary objective of demonstrating equivalent efficacy of HD203 and ETN. HD203 was well tolerated, with safety comparable with ETN in this population of patients with RA.

Trial registration number

NCT01270997; Results.

A Bottom-Up Whole-Body Physiologically Based Pharmacokinetic Model to Mechanistically Predict Tissue Distribution and the Rate of Subcutaneous Absorption of Therapeutic Proteins

The ability to predict subcutaneous (SC) absorption rate and tissue distribution of therapeutic proteins (TPs) using a bottom-up approach is highly desirable early in the drug development process prior to clinical data being available. A whole-body physiologically based pharmacokinetic (PBPK) model, requiring only a few drug parameters, to predict plasma and interstitial fluid concentrations of TPs in humans after intravenous and subcutaneous dosing has been developed. Movement of TPs between vascular and interstitial spaces was described by considering both convection and diffusion processes using a 2-pore framework. The model was optimised using a variety of literature sources, such as tissue lymph/plasma concentration ratios in humans and animals, information on the percentage of dose absorbed following SC dosing via lymph in animals and data showing loss of radiolabelled IgG from the SC dosing site in humans. The resultant model was used to predict t_max and plasma concentration profiles for 12 TPs (molecular weight 8–150 kDa) following SC dosing. The predicted plasma concentration profiles were generally comparable to observed data. t_max was predicted within 3-fold of reported values, with one third of the predictions within 0.8–1.25-fold. There was no systematic bias in simulated C_max values, although a general trend for underprediction of t_max was observed. No clear trend between prediction accuracy of t_max and TP isoelectric point or molecular size was apparent. The mechanistic whole-body PBPK model described here can be applied to predict absorption rate of TPs into blood and movement into target tissues following SC dosing.

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.

Biosimilars in rheumatology: what the clinician should know

Biosimilars are now a reality in rheumatology. Although analytical and non-clinical procedures to establish similarity have evolved significantly, clinical trials demonstrating equivalent efficacy and safety are absolutely required for all biosimilars. The design of such trials, including equivalence and non-inferiority statistical approaches, are discussed. Clinical evidence on biosimilars that have been approved recently or are presently being developed for use in rheumatology is also reviewed and contrasted with that available for biomimics (or intended copies), which are non-innovator biologics that are marketed in several countries but have not undergone review according to a regulatory pathway for biosimilars.

Etanercept biosimilars

Etanercept was the first tumour necrosis factor alpha antagonist approved in the USA for the treatment of rheumatoid arthritis, in 1998, and then for other diseases. With the etanercept patent set to expire in the EU in 2015, a number of etanercept copies have reached the production phase and are undergoing clinical trials, with the promise of being cheaper alternatives to the reference product. In a global scenario that is favourable to the entry of biosimilars, this article discusses the stage of development, manufacture, clinical trials and the regulatory process involved in the approval of etanercept biosimilars, compiling the literature data. Reducing treatment cost is the principal attraction for biosimilars to emerge in the global market. It is essential for the doctors’ decision on the prescription of these medications, as well as for payers, to have clearly defined studies of clinical equivalence, quality, and safety in order to better evaluate the various copies of etanercept. The authors discuss the need to harmonize different national regulations and the introduction of effective pharmacosurveillance systems for prompt recognition of adverse effects in copies of biopharmaceuticals that differ from those found in the reference products.