Review Open Access
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2017; 23(11): 1932-1943
Published online Mar 21, 2017. doi: 10.3748/wjg.v23.i11.1932
Insights on the use of biosimilars in the treatment of inflammatory bowel disease
Michael K Zheng, David Q Shih, Gary C Chen
Michael K Zheng, David Q Shih, F. Widjaja Foundation, Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
Gary C Chen, Comprehensive Digestive Institute of Nevada, Las Vegas, NV 89113, United States
Author contributions: Zheng MK wrote the manuscript; Shih DQ and Chen GC provided critical revisions and final approval.
Conflict-of-interest statement: The authors have declared that no conflict of interest exists.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Gary C Chen, MD, Comprehensive Digestive Institute of Nevada, 8530 West Sunset Road, Suite 230, Las Vegas, NV 89113, United States.
Telephone: +1-702-4834483 Fax: +1-702-4834493
Received: November 23, 2016
Peer-review started: November 25, 2016
First decision: December 19, 2016
Revised: January 5, 2017
Accepted: February 17, 2017
Article in press: February 17, 2017
Published online: March 21, 2017


Biologic therapy, such as those that target tumor necrosis factor (TNF) signaling, has proven to be an efficacious method of treatment for patients with inflammatory bowel disease (IBD) with regards to symptom management and mucosal healing. However, the rising prevalence of IBD worldwide and the ever-increasing burden of biologic pharmaceuticals in the health care industry is alarming for insurance companies, clinicians, and patients. The impending patent expiry and the relatively high costs of biologics, particularly anti-TNF agents, have paved the way for biosimilar development for IBD. The United States Food and Drug Administration defines a biosimilar as a biological product that is highly similar to its reference medicinal product, with no clinically meaningful differences in terms of safety, purity, and potency. The hope with biosimilars is that their entry into the market will be able to drive competition between pharmaceutical companies to reduce prices like that of the generic market, and that access to appropriate biologic treatments for IBD patients is increased in the long-term. Yet, there are challenging issues such as indication extrapolation and interchangeability that are still being debated in the field of IBD and must be addressed in future issued guidance. This review will discuss the issues and implications concerning the use of biosimilar therapy for IBD.

Key Words: Biosimilar, Biologic, Inflammatory bowel disease, Ulcerative colitis, Crohn’s disease, Indication extrapolation, Interchangeability

Core tip: The expiration of patent protection for various biologics and increasing health care expenses has paved the way for biosimilars to enter the market. The introduction of biosimilars is expected to produce cost savings in the health care industry as well as provide patients with inflammatory bowel disease with wider access to treatment.


There are two conditions that mainly characterize inflammatory bowel disease (IBD): ulcerative colitis (UC) and Crohn’s disease (CD). These are chronic, relapsing, immune-mediated inflammatory diseases of the gastrointestinal tract. Whereas UC is an inflammatory condition that only affect the colon, CD is a chronic inflammatory condition with pathological features such as patchy transmural inflammation and fibrostenosis[1]. Urbanization, industrialization, and lifestyle are all factors that contribute to the rising incidence of IBD worldwide[2]. It has been estimated that approximately 1.4 million Americans are affected by IBD and afflicted with recurrent symptoms of bloody diarrhea, abdominal pain, bowel obstruction, and other co-morbid conditions[3,4].

The introduction of biologic therapy for IBD proved to be a breakthrough for patients with the disease[5]. Biologic products are highly complex molecules that are manufactured using living organisms[6]. In the pharmaceutical industry, biologics that are classified as monoclonal antibodies (mABs), particularly those that serve to antagonize tumor necrosis factor (TNF) signaling, have provided specialists and IBD patients with a proven and efficacious method of symptom management, mucosal healing, and prevention of long-term complications[7,8]. TNFα is a cytokine responsible for causing an inflammatory response towards tissue damage, and it was discovered to play an important role in the pathophysiology of chronic immunological diseases, including IBD and rheumatoid arthritis (RA)[9]. In addition, mABs that antagonize the α4β7 integrin have been developed to treat IBD. The α4β7 integrin was found to be involved in interactions that facilitate T-cell extravasation into the GI tract[10]. Patients who fail to respond or demonstrate hypersensitivity to anti-TNF therapy may also be treated with biologics that target the interleukin (IL)-12 and IL-23 pathways. IL-12 and IL-23 are proinflammatory cytokines that play a role in the differentiation of T-helper cells into type 1 T-helper cells as well as T-helper cell proliferation[11]. Currently, four anti-TNF biologics (infliximab, adalimumab, golimumab, and certolizumab) and two anti-integrin biologics (natalizumab and vedolizumab) have been approved for use in IBD treatment, while one anti-IL biologic that targets IL-12 and IL-23 (ustekinumab) has been approved for CD treatment[12,13].

Despite the effectiveness of biologics in treating IBD, the approaching patent expiry of certain anti-TNF agents has triggered the development of highly similar versions of these drugs known as “biosimilars” (Table 1). The approval of these biosimilar therapies is expected to generate competition in the pharmaceutical market that will reduce the financial burden of patient care and allow more patients to access treatment. However, the effectiveness of biosimilars is being debated due to several factors including an expedited regulatory approval process for biosimilar therapy and the notion that once approved, a biosimilar may be approved for all other indications for which the reference medicinal product (RMP) has been approved, without the need for clinical trials for the latter indications[14,15]. The purpose of this review is to discuss the emergence and implications of biosimilar market entry and to evaluate the progress of biosimilar therapy for IBD.

Table 1 Comparison of biologics and biosimilars.
Development costs[26,103]Approximately $2 billionApproximately $100-250 million
CharacterizationExhibits heterogeneityExhibits heterogeneity
Patent duration20 yr; up to 12-yr exclusivity periodNo patent licensing
Approval processSubmission of a BLASubmission of an aBLA
ImmunogenicityPossible riskPossible risk
Indication extrapolationNot permittedCase-by-case basis
What are biologics?

Biologic medicines are considerably more complex than small-molecule chemical generics. Compared with small-molecule medicines, which can be synthesized relatively easily and replicated chemically, biologics are large and complex three-dimensional structures produced using living cell lines and are difficult to replicate[16].

Whereas chemical generics only require about 50 critical tests during the manufacturing process, biologics demand a highly regulated manufacturing process consisting of 250 or more tests and a sophisticated quality control protocol[17]. In order to produce biologic agents, the gene for the protein of interest is inserted into a cell that produces and secretes the biologic agent in culture. After harvesting, the biologic undergoes protein purification before product formulation and packaging for clinical use[16]. Biologics are typically made in living cells that are highly sensitive to environmental changes and external conditions (such as temperature, light, and shear forces). As a result, different batches of the same biologic will vary in structural properties such as size, post-translational modifications, and folding pattern[17,18].

For patients with IBD, biologic treatment is an effective therapy. Infliximab (IFX) is a human-murine chimeric mAB that blocks the action of TNFα (anti-TNF) and is used to treat various immune-mediated inflammatory diseases[19]. Remicade, an IFX biologic used in the treatment of various auto-immune and inflammatory diseases, has been approved as therapy for induction and maintenance of moderate-to-severe CD and UC in both adult and pediatric IBD patients[20]. Subsequent to the approval of IFX, three other anti-TNF drugs (adalimumab, certolizumab pegol, and golimumab) and two anti-integrin biologics (natalizumab and vedolizumab) are approved therapies to treat IBD, while one anti-IL biologic that targets IL-12 and IL-23 (ustekinumab) has been approved for CD treatment[12,13].

What are biosimilars?

The regulatory pathway of a biologic drug is a time-consuming process that requires successful clinical trials that demonstrate clinical efficacy as well as approval from regulatory agencies such as the United States Food and Drug Administration (FDA) and European Medicines Agency (EMA)[14,21,22]. However, in the context of biosimilars, regulatory agencies only need to ensure that high similarity or comparability is demonstrated between the biosimilar and its RMP before a biosimilar candidate can be approved and marketed, resulting in a simpler approval pathway[15].

According to the FDA, a biosimilar is a biological product that is highly similar to a RMP, with no clinically meaningful differences in terms of safety, purity, and potency[22]. Biosimilars and generic drugs both represent competition towards brand-name drugs. Although a manufactured generic is an exact copy of the original small-molecule medicine, it is not possible to generate identical copies of a biologic[23]. Since biologics are difficult to replicate, biosimilars are manufactured using alternate methods such that the final product is almost identical to the RMP with respect to the primary amino acid sequence[24]. Due to the inherent variability of the living bacteria-based systems used to make biosimilar drugs, there is microheterogeneity between biosimilar and RMP[25].

The emergence of biosimilar therapies is an inevitable outcome of patent expiration. From the date of filing, a drug’s patent lasts up to 20 years, with exclusivity lasting up to 12 years, according to the Biologics Price and Competition Innovation Act of 2009[26]. Pharmaceutical companies rely on patent exclusivity and protection to benefit from investment return. Once a patent expires, companies are immediately able to market generics, which usually have lower prices driven by competition[27]. The anticipation with biosimilars is that their entry into the market will be able to drive competition between pharmaceutical companies, to reduce prices comparably to how the generic market has, and to increase overall patient access to appropriate biologic treatments in the long-term. Currently, only two biosimilars have been approved for use in IBD in the United States: infliximab-dyyb and adalimumab-atto[28,29]. However, multiple anti-TNF biosimilars have either been proposed, are being tested in late stage clinical trials, or are awaiting approval from regulatory agencies (Table 2).

Table 2 Proposed anti-tumor necrosis factor biosimilars1.
Reference medicinal productBiosimilar name
InfliximabInfliximab-dyyb (Celltrion)2
SB2 (Samsung Bioepis)
PF-06438179 (Sandoz)
BOW015 (Epirus)
AdalimumabAdalimumab-atto (Amgen)2
SB5 (Samsung Bioepis)
ZRC-3197 (Zydus Cadila)
MSB11022 (Merck KGaA)
Certolizumab pegolPF688 (PFEnex)
GolimumabBOW100 (Epirus)
Mechanism of action

IBD is characterized by immune dysregulation in a genetically predisposed individual, resulting in overproduction of TNFα by macrophages, monocytes, and T cells[30,31]. Anti-TNF therapy is an efficacious method that can treat IBD by blocking proinflammatory mediator TNF. Anti-TNF mAbs can also induce the formation of regulatory immunosuppressive macrophages and anti-inflammatory cytokines to further treat IBD[31]. Certain mAbs such as IFX and adalimumab (ADA), but not certolizumab, have the ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC), an immune response characterized by the lysis of target cells by activated effector cells, including natural killer cells, monocytes, macrophages, neutrophils, and eosinophils[32]. The crystallizable fragment of the IgG1 antibodies of these mAbs is necessary to exhibit ADCC[33].

Molecules in the same class, such as TNF inhibitors, may be extrapolated across all indications because they share the same mechanism of action. Extrapolation across indications is a process that may be considered when there are changes in manufacturing from an originator biologic or route of administration[18]. Typically, clinical data that corresponds to one indication may be extrapolated to additional indications based on information on comparability. Because clinical efficacy of the RMP is already established, the number of preclinical and clinical studies required for approval may be less for biosimilars, and studies may only be required for a subset of indications[34]. Clinical studies and analytical tests that observed comparability in physiochemical features and mechanism of action between RMP and biosimilar supported the approval of infliximab-dyyb across all indications of IFX by the FDA and EMA[18,28,35].

Pharmacokinetic profile

Pharmacokinetics (PK) refers to various factors (absorption, bioavailability, distribution, metabolism, and excretion) involved with the movement of a drug into, through, and out of the body. In addition to patient-related factors (e.g., genetic makeup, sex, body mass index, age, and disease severity), chemical properties can also influence PK parameters[36]. Compared with small-molecule medicines, biologics and biosimilars will have a slower rate of absorption, smaller volume of distribution, different mechanisms of paracellular and transcellular movement, and different routes of clearance[37]. A biosimilar must display a comparable PK profile to the RMP. Results from a randomized study indicated that three formulations of IFX [infliximab-dyyb, United States RMP, and European Union (EU) RMP] had highly similar PK and safety profiles[38]. In addition, an understanding of PK is necessary to optimize therapeutic development and dosing in patients[37].


Biologics have been shown to elicit an immunogenic response in some patients, characterized by a release of antibodies by antibody-secreting B cells[39]. When present, anti-drug antibodies can neutralize the clinical efficacy of a biologic as well as cause unpredictable side effects and loss of response[40]. Immunogenicity is a major health concern with all biologics as well as biosimilars. Manufacturing, post-translational modifications, route of administration, and patient characteristics are several factors known to influence immunogenicity[41].

Concomitant use of immunomodulators such as azathioprine (AZA) and methotrexate (MTX) can prevent immunogenicity by decreasing the formation of anti-drug antibodies and reducing systemic inflammation[42]. The SONIC study evaluated the safety of efficacy of treating CD patients with IFX or AZA alone or in combination therapy. At week 26, there was a greater occurrence of corticosteroid-free remission and mucosal healing in those treated with combination therapy than with monotherapy. Additionally, there were fewer patients that developed serious infections in the combination therapy group, compared with both the IFX and AZA groups[43]. A similar study, UC SUCCESS, was performed to evaluate combination therapy in UC patients. At week 16, greater occurrence of mucosal healing and corticosteroid-free remission was observed those treated with combination therapy than with IFX or AZA alone[44]. The COMMIT study evaluated the safety and efficacy of IFX alone or in combination with MTX in CD patients. Although combination therapy was well tolerated, the number of patients who achieved corticosteroid-free remission at week 14 and maintained remission at week 50 was similar in both groups. However, only 4% of patients who received MTX developed antibodies to IFX, compared with 20% who received IFX alone. Furthermore, trough serum concentrations of IFX was also higher, albeit not statistically significant, in patients who received MTX[45].

The use of immunomodulatory agents on biosimilar treatment has shown to be feasible. In an extension of the PLANETRA study, all enrolled patients received intravenous infliximab-dyyb and concomitant methotrexate. Both the maintenance and switch groups displayed a similar proportion of patients with anti-drug antibodies[46]. Notably, the EMA also mentions the concomitant use of methotrexate in the European public assessment report for infliximab-dyyb[35].

Potential cost savings with biosimilars

The high prices of biologic pharmaceuticals have placed a burden on the healthcare industry, accounting for a continually increasing share of drug spending in the United States and limiting patient access to appropriate treatment. The Office of the Assistant Secretary for Planning and Evaluation estimates that United States drug spending totaled about $457 billion in 2015, making up 16.7% of overall health care spending. Notably, prescription drug expenditures are rising at a faster rate than overall spending, due to factors such as population growth, inflation, and a higher number of prescriptions per patient[47].

The estimated total costs of IBD in the United States range from $14.6B to $31.6B[48]. The growing prevalence of the disease worldwide, in conjunction with the high costs, is concerning for the economy and may lead to unsustainable healthcare costs in the future. Compared to patients without the disease, direct medical expenditures have been found to be around $13663 to $17434 higher for patients with CD and $10039 to $12615 higher for patients with UC[49].

Biosimilars are expected to produce savings across the board in the health care industry as a result of various factors, such as reduced research and development costs, competition driven by patent expiry, and a simpler approval pathway. An Excel-based model of Remsima for the treatment of various inflammatory autoimmune diseases was created to estimate the budget impact of Remsima. The model, which covers five countries (Germany, the United Kingdom, Italy, the Netherlands, and Belgium) projects the biosimilar to induce cost savings over one year of $63 million (pounds converted to dollars) and the treatment of 3900 additional patients[50]. Furthermore, another budget impact model of Remsima in six different countries (Bulgaria, Czech Republic, Hungary, Poland, Romania, Slovakia) was developed while taking into two scenarios: BSc1 (interchangeability disallowed) and BSc2 (interchangeability allowed, 80% of patients taking IFX are interchanged to biosimilar). In this model, which estimates budget impact of Remsima in the treatment of RA only, savings of $21M (BSc1) and $29M (BSc2) are projected over 3 years, as well as the treatment of an additional 1200 to 1800 patients[51].

The EU has provided the healthcare industry with a preliminary impression of biosimilar market entry. Biosimilars have been available in the EU since 2006, and the observed average list prices are 30% lower than the RMP, compared to the 70% to 80% savings that generics induce[26,52]. Because biosimilars are more difficult to manufacture, the cost reduction is not expected to be as drastic as seen with generics.

Currently, filgrastim-sndz (Zarxio), an anti-cancer drug, infliximab-dyyb, and adalimumab-atto are the only biosimilars approved in the United States[28,29,53]. The entry of biosimilars into the United States market is important for the overall development and financial success of the pharmaceutical industry, bearing in mind that a majority of world biologics sales come from the United States[54]. From 2014-2024, it is anticipated that the entry of the 11 most likely biosimilars into the market will lead to $250 billion in savings for the American healthcare industry, with the possibility of greater disease control and reduced inpatient stays and outpatient visits[55].

Wider accessibility for patients

The entry of biosimilars to market is expected to give patients more choices and greater access to treatment. Prior to the development of biosimilars, those who required biologic therapy were either restricted to a limited number of costly treatment options or placed on a waiting list. A cross-sectional study, performed in 49 European countries, revealed that RA patients in lower income countries struggle with affordability and have less access to biologic and synthetic disease-modifying drugs[56]. Fortunately, due to projected cost reductions associated with biosimilars, a large number of patients are expected to have a larger complement of options available to them earlier in the course of the disease.

Furthermore, if switching between a particular RMP and its biosimilar are observed to be clinically noninferior to continued treatment of the RMP, then concerns about biologic shortages and waiting lists would potentially be alleviated. In 2014, there were 1000 additional patients in the Czech Republic who were able to initiate treatment than in the previous year, due to the cost savings of biosimilars[57].

Indication extrapolation

There is uncertainty as to the level of efficacy of certain biologic molecules in different indications. While IFX and etanercept (ETN) are effective in treating RA, ETN was determined to be futile in treating CD[58]. Studies show that in patients with CD, both IFX and ETN are successful in TNF blocking, but only IFX is capable of inducing apoptosis in order to reduce the number of inflammatory cells[59]. Notably, IFX provides clinical improvement in RA, but not by the induction of apoptosis[60].

The extrapolation of indications for infliximab-dyyb for the indications of IFX has also prompted questioning. IFX is effective in multiple tissues and organ systems (joints, axial skeleton, GI tract, and skin). However, even though the approval of infliximab-dyyb in the EU was mainly supported by studies in ankylosing spondylitis (AS), a chronic inflammatory disease that affects the spinal vertebrae and sacroiliac joints, and RA, the specific distribution and effectiveness of IFX and infliximab-dyyb to affected tissues is not known, presenting a potential problem in indication extrapolation[34,61-63]. In 2014, Health Canada approved infliximab-dyyb for all indications except for UC and CD due to a lack of clinical data demonstrating proper mechanism of action in all indications of IFX, and residual uncertainty regarding the role and impact of small differences in ADCC[34,64,65]. Because anti-TNF agents may also depend on ADCC in addition to TNFα neutralization, changes in ADCC tests pose a challenge for extrapolation[33].


As with biologics, it is important to take into consideration the unpredictable risk of immunogenicity when introducing a biosimilar to the market. While effective for treating inflammatory diseases such as IBD, some patients either fail to respond or develop a loss of response. Because indication extrapolation for a biosimilar requires less clinical data than the initial approval of a biologic would, information regarding immunogenicity of the biosimilar in patients for indications without substantial data becomes difficult to support without performing extensive clinical trials[34]. The FDA and World Health Organization have advised that immunogenicity be investigated in populations that are at the highest risk of an immune response and immune-related adverse events[15,66]. Furthermore, performing in vivo and in vitro assays (e.g., size exclusion, western blots, and enzyme-linked immunosorbent assays) throughout development can lessen the probability of an immunogenic response[39].

Recent data suggests that it may not be appropriate to extrapolate immunogenicity data from the RMP to the biosimilar. Following results of a study which revealed cross-reactivity between anti-IFX antibodies and infliximab-dyyb, the European League Against Rheumatism stated that switching from IFX to infliximab-dybb may not be appropriate for all patients[67]. Given the unpredictability of anti-drug antibody formation, diagnostic tests have been developed in order to better estimate the efficacy of biologics and biosimilars in patients with IBD. The Anser IFX and Anser ADA, developed by Prometheus Laboratories, were designed to measure the serum levels and antibodies of patients being treated with IFX or ADA, respectively. In a cohort study of patients with acute UC (n = 115), detectable trough serum concentrations of IFX were shown to predict improved outcomes[68]. Recently, the Anser IFX was validated for use in patients who are treated with infliximab-dyyb[69].


One of the major obstacles for the entry of biosimilars into the market is interchangeability. The Abbreviated New Drug Application (ANDA) is an application that uses bioequivalence as a basis to demonstrate that a new generic is similar enough to the original branded drug. Most generics are considered interchangeable once the ANDA is approved, and pharmacists are allowed to switch branded drugs for generics at the point of purchase, subject to state law[70,71]. Conversely, interchangeability of biosimilars is not immediately granted upon ANDA approval, which poses a challenge for clinical use[72].

Manufacturers face concerns with both clinician and patient acceptance, as well as the reluctance to use the biosimilar in treatment, especially if such a change is to alter a long established prescribing practice[73]. The FDA states that an interchangeable product is “expected to produce the same clinical result as the RMP in any given patient and, if the biological product is administered more than once to an individual, the risk in terms of safety or diminished efficacy of alternating or switching between the use of the biological product and the RMP is not greater than the risk of using the RMP without such alternation or switch[74]”. As a result, a biosimilar product may not necessarily be interchangeable. Because an application for interchangeability requires the fulfillment of additional criteria, manufacturers may decide not to pursue the “interchangeable” designation. Without investing in extra clinical trials, patient and clinician confidence in non-interchangeable biosimilars could potentially decrease, despite a more rapid market entry[70].

In the EU, a majority of biosimilars had relatively little market share because of a lack of interchangeability[75]. A majority of United States states and Puerto Rico have either considered, passed legislation, or enacted law regarding the automatic substitution of biologics for biosimilars at the pharmacy level[76]. Automatic substitution allows pharmacists to replace biologics with biosimilars without informing or obtaining approval from the prescribing physician[77]. There are currently no studies that demonstrate the implications of cross-switching (switching between two biosimilars), reverse-switching (switching from a biosimilar to its RMP), or switching between multiple biosimilars. However, it is possible that switching between multiple biosimilars may lead to an immunogenic reaction and reduced efficacy of the drug. Because antibodies can develop within 2 to 3 treatments, an updated statement from the European Crohn’s and Colitis Organization advises against switching within six months of initiating treatment for non-medical reasons[78]. Ultimately, the FDA is expected to issue their official guidance on interchangeability by the end of 2017[79].


The results of two randomized and double-blind clinical studies, PLANETRA and PLANETAS, contributed to the approval of infliximab-dyyb in the EU for all the indications of the RMP (infliximab): RA, CD, UC, AS, psoriatic arthritis (PsA), and psoriasis (PsO)[80]. Six hundred and six RA patients enrolled in PLANETRA were randomized to receive either IFX (n = 304) or infliximab-dyyb (n = 302) in combination with MTX and folic acid. In PLANETAS, 250 AS patients were randomized to receive either IFX (n = 125) or infliximab-dyyb (n = 125) alone. At weeks 14 and 30 of both studies, the biosimilar was shown to have demonstrated to have highly similar PK, efficacy, safety, and immunogenicity[61,62]. In 2016, results from a secondary analysis of PLANETAS were made available. Through week 54, the observed PK parameters and immunogenicity remained similar in the two treatment groups. Withdrawal rates were similar in both the biosimilar (n = 19) and RMP (n = 21) treatment groups, with the most common cause being the case of a treatment-emergent adverse event (TEAE). The most common TEAEs (occurring in over 10% of patients in each treatment group) were abnormal liver function test and infusion-related reaction[63].

Several studies have been performed to address infliximab-dyyb induction in IBD (Table 3). Mixed results suggest that infliximab-dyyb and IFX may not have similar clinical efficacy and safety in patients with the disease. In Ireland, a study was performed to compare 14 IBD patients taking an IFX biosimilar (Inflectra) from January to July 2014 to 22 IBD patients commenced on IFX from December 2011 to December 2013. Results indicated that Inflectra demonstrated a significant decrease in clinical efficacy, with a 29% increase in surgery rate and 75% increase in hospital readmission[81]. Another retrospective multi-center study evaluated the efficacy and safety of infliximab-dyyb in anti-TNF naïve UC (n = 42) and CD (n = 32) patients. After switching, therapeutic efficacy was maintained in 93% (25/27) of CD patients and 67% (6/9) UC patients at 54 wk. There were adverse events reported in 11% of UC patients, but the results indicated comparable efficacy, safety, and interchangeability between RMP and biosimilar[82]. Clinical data from 46 CD and 32 UC patients in a infliximab-dyyb induction study demonstrated comparable efficacy and safety to the RMP. At week 14, 76% (32/42) of CD patients and 56% (18/32) of UC patients were in clinical remission, and decreases in the Harvey-Bradshaw Index (HBI), calprotectin levels, and C-reactive protein (CRP) levels were observed in both indications. In addition, no adverse events were reported[83,84]. A prospective, multicenter, nationwide cohort that examined infliximab-dyyb induction in CD (n = 126) and UC (n = 84) revealed clinical response in 81.4% (CD) and 77.6% (UC) of patients as well as remission rates of 53.6% (CD) and 58.6% (UC). Adverse events were reported in 17.1% of all patients[85].

Table 3 Clinical studies on infliximab-dyyb induction in inflammatory bowel disease.
Jahnsen et al[84]Prospective observationalCD = 46; UC = 32Clinical remission rate at week 14: 79% (CD), 56% (UC)No adverse events reported
Significant decrease in CRP, calprotectin
Jung et al[82]Retrospective multicenterCD = 32; UC = 42Clinical response at week 54: 87.5% (CD), 100% (UC)Adverse events in 11% of UC patients
Clinical remission rate at week 54: 75% (CD), 50% (UC)
Gecse et al[85]Prospective, multicenter, nationwide cohortCD = 126; UC = 84Clinical response at week 14: 81.4% (CD), 77.6% (UC)Adverse events in 17.1% of all patients
Clinical remission rate at week 14: 53.6% (CD), 58.6% (UC)
Murphy et al[81]DescriptiveIBD = 36CRP levels: increase in 93% of Inflectra patients, decrease in 100% of Remicade patients29% increase in hospital readmission and 75% increase in surgery rates with Inflectra patients
(Remicade = 22;
Inflectra = 14)
Sieczkowska et al[86,104]Switch from RMP to Infliximab-dyybPediatric CD = 32; Pediatric UC = 7Clinical remission rate: 88% (CD), 57% (UC)No adverse events reported
Decrease in PCDAI, CRP, ESR
Smits et al[87]Prospective, observational, cohort switchCD = 57; UC = 26No significant change in DAI, CRP, calprotectin at week 16No adverse events reported

Currently, there is limited data that addresses the switching to a biosimilar from its RMP in IBD. However, studies have suggested that switching between biosimilar and RMP in IBD patients is feasible[86,87]. NOR-SWITCH was a randomized, double-blind, parallel-group study in Norway that evaluated the safety and efficacy of a single switch from IFX to infliximab-dyyb in patients with various inflammatory diseases (RA, spondyloarthritis, PsA, UC, CD, and chronic PsO). The study began in October 2014 and is expected to be completed in January 2017[88]. Data presented at the United European Gastroenterology Week 2016 revealed that switching to infliximab-dyyb was not inferior to continued treatment with RMP IFX[89].


Samsung Bioepis’s SB2 (Flixabi), an IFX biosimilar, was approved in the EU for all the indications of infliximab, as listed above. The approval of Flixabi was facilitated by a randomized, double-blind Phase 3 study which demonstrated comparable PK and immunogenicity to IFX, and equivalent values for ACR20 in both the SB2 and IFX treatment groups at week 30 and 54[90,91].


Sandoz acquired the rights to Pfizer’s IFX biosimilar, PF-06438179, in February 2016[92]. In September 2013, a Phase 1 study, REFLECTIONS (B537-02), comparing PF-06438179 to IFX in healthy volunteers (n = 146) indicated comparability in the PK and immunogenicity profiles of both treatment groups[93]. REFLECTIONS (B537-02) is an ongoing randomized, double-blind Phase 3 clinical study comparing PF-06438179 to IFX in combination with methotrexate in patients with acute RA. The study began in August 2014 and is expected to be completed in May 2017[94].


In September 2014, Epirus Biopharmaceutical’s BOW015 became the first IFX biosimilar to be approved in India, facilitated by Phase 3 clinical data of BOW015 in RA patients[95]. Currently, Epirus has launched another Phase 3 study in Europe, the UNIFORM study, comparing BOW015 and IFX in patients with active RA. Data is expected after the study’s primary completion date in July 2017[96].


Amgen submitted an abbreviated Biologics License Application (aBLA) to the FDA in November 2015 for adalimumab-atto (Amjevita), a biosimilar candidate to its ADA biologic, Humira, following the completion of two phase 3 studies[97]. The FDA approved Amjevita across all eligible indications of Humira in September 2016. Amgen’s first study was a randomized, double-blind, active-controlled phase 3 comparative study performed to demonstrate comparable safety, efficacy, and immunogenicity of ABP 501 and ADA with patients with moderate-to-severe RA. Amgen believes that the study met the primary endpoint of ACR20. Secondary endpoints, ACR50 and ACR70, as well as the incidence of TEAEs were also comparable between ADA and ABP 501[98]. Another randomized, double-blind phase 3 study of Amjevita was performed in patients with moderate-to-severe plaque PsO. Results achieved the primary endpoint for efficacy of the study with a percent improvement in Psoriasis Area and Severity Index from baseline to week 16 of treatment, and safety and immunogenicity were observed to be comparable between ADA and Amjevita[99].


In December 2014, the first ADA biosimilar, Zydus Cadila’s ZRC-3197 (Exemptia) launched in India[100]. Approval of ZRC-3197 was facilitated by a randomized, double-blind study comparing Exemptia and ADA in patients with RA, yielding comparability data demonstrating high similarity between the biosimilar and the RMP in terms of efficacy, tolerability, and safety. The 12-wk study saw only 3 of 120 subjects drop out, all due to adverse events, and no deaths were reported[101].


In March 2016, Merck KGaA announced the initiation of AURIEL-PsO, a randomized double-blind study to evaluate the safety and efficacy of its ADA biosimilar candidate, MSB11022, compared with ADA in patients with moderate-to-severe plaque PsO. Data is expected in December 2016, with the study to be completed around September 2017[102].


Biologic therapy has greatly facilitated treatment for IBD, and the introduction of biosimilars has the potential to be a breakthrough development for IBD patients. Increasing prescription drug expenditures have limited patient access to the appropriate biologic treatment, contributing to a heightened interest in biosimilars, which are expected to trigger cost savings upon biologic patent expiry. Reflecting upon the biosimilar experience in the EU, savings of around 30% from the RMP were observed. Moreover, current studies and experience provide optimism with regards to future cost savings and interchangeability with their RMPs. The FDA’s recent approval of Inflectra marks significant progress in the emergence of biosimilar therapy in the United States. Ultimately, as more biosimilars enter the market, competition is expected to drive prices down.

Perhaps the greatest hurdle that pharmaceutical companies face is clinician and patient acceptance. Issues such as immunogenicity and interchangeability cannot be avoided. It has been suggested that the development of anti-drug antibodies may have an inhibitive effect on clinical response and patient outcomes. Although diagnostic tests such as the Anser IFX are able to provide some clarification to patients, additional studies are necessary in order to clear up any uncertainty with regards to the influence of anti-drug antibodies. In addition, taking steps to improve manufacturing processes and production may contribute to avoid changes that influence an immunogenic response in patients. As more data becomes available, biosimilars have the opportunity to increase patient access to a more affordable form of appropriate treatment. Given the large number of studies in progress, it is conceivable that more promising results will expedite the transition towards biologic and biosimilar interchangeability as well as higher confidence in interchangeability and active switching between biosimilar and RMP.

Hopefully, when the appropriate guidance is finalized, the FDA will be able to answer many of the questions that manufacturers and companies have pertaining to biosimilar labeling and interchangeability. With the necessary data and guidance at their disposal, it will be feasible for clinicians to develop a treatment plan that is more personalized and tailored towards specific patients than before.


Manuscript source: Invited manuscript

Specialty type: Gastroenterology and hepatology

Country of origin: United States

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P- Reviewer: Day AS, Gassler N, Seidman EG S- Editor: Gong ZM L- Editor: A E- Editor: Zhang FF

1.  Cassinotti A, Ardizzone S, Porro GB. Adalimumab for the treatment of Crohn’s disease. Biologics. 2008;2:763-777.  [PubMed]  [DOI]  [Cited in This Article: ]
2.  Molodecky NA, Soon IS, Rabi DM, Ghali WA, Ferris M, Chernoff G, Benchimol EI, Panaccione R, Ghosh S, Barkema HW. Increasing incidence and prevalence of the inflammatory bowel diseases with time, based on systematic review. Gastroenterology. 2012;142:46-54.e42; quiz e30.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2653]  [Cited by in F6Publishing: 2489]  [Article Influence: 241.2]  [Reference Citation Analysis (0)]
3.  Loftus EV, Schoenfeld P, Sandborn WJ. The epidemiology and natural history of Crohn’s disease in population-based patient cohorts from North America: a systematic review. Aliment Pharmacol Ther. 2002;16:51-60.  [PubMed]  [DOI]  [Cited in This Article: ]
4.  Langan RC, Gotsch PB, Krafczyk MA, Skillinge DD. Ulcerative colitis: diagnosis and treatment. Am Fam Physician. 2007;76:1323-1330.  [PubMed]  [DOI]  [Cited in This Article: ]
5.  Rencz F, Péntek M, Bortlik M, Zagorowicz E, Hlavaty T, Śliwczyński A, Diculescu MM, Kupcinskas L, Gecse KB, Gulácsi L. Biological therapy in inflammatory bowel diseases: access in Central and Eastern Europe. World J Gastroenterol. 2015;21:1728-1737.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 55]  [Cited by in F6Publishing: 50]  [Article Influence: 7.9]  [Reference Citation Analysis (0)]
6.  Revers L, Furczon E. An introduction to biologics and biosimilars. Part I: Biologics: What are they and where do they come from? Can Pharm J. 2010;143:134-139.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 16]  [Cited by in F6Publishing: 1]  [Article Influence: 1.3]  [Reference Citation Analysis (0)]
7.  Moss AC. Optimizing the use of biological therapy in patients with inflammatory bowel disease. Gastroenterol Rep (Oxf). 2015;3:63-68.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 48]  [Cited by in F6Publishing: 38]  [Article Influence: 6.9]  [Reference Citation Analysis (0)]
8.  Cintolo M, Costantino G, Pallio S, Fries W. Mucosal healing in inflammatory bowel disease: Maintain or de-escalate therapy. World J Gastrointest Pathophysiol. 2016;7:1-16.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 14]  [Cited by in F6Publishing: 15]  [Article Influence: 2.3]  [Reference Citation Analysis (1)]
9.  Olesen CM, Coskun M, Peyrin-Biroulet L, Nielsen OH. Mechanisms behind efficacy of tumor necrosis factor inhibitors in inflammatory bowel diseases. Pharmacol Ther. 2016;159:110-119.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 62]  [Cited by in F6Publishing: 57]  [Article Influence: 10.3]  [Reference Citation Analysis (0)]
10.  Lin L, Liu X, Wang D, Zheng C. Efficacy and safety of antiintegrin antibody for inflammatory bowel disease: a systematic review and meta-analysis. Medicine (Baltimore). 2015;94:e556.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 21]  [Cited by in F6Publishing: 7]  [Article Influence: 3.0]  [Reference Citation Analysis (0)]
11.  Engel T, Kopylov U. Ustekinumab in Crohn’s disease: evidence to date and place in therapy. Ther Adv Chronic Dis. 2016;7:208-214.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 16]  [Cited by in F6Publishing: 17]  [Article Influence: 2.7]  [Reference Citation Analysis (0)]
12.  Danese S, Vuitton L, Peyrin-Biroulet L. Biologic agents for IBD: practical insights. Nat Rev Gastroenterol Hepatol. 2015;12:537-545.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 193]  [Cited by in F6Publishing: 179]  [Article Influence: 27.6]  [Reference Citation Analysis (0)]
13.  FDA Approves STELARA® (Ustekinumab) for Treatment of Moderate to Severe Crohn’s Disease. CCFA 2016 [cited 2016-11-15];.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
14.  European Medicines Agency. Guideline on similar biological medicinal products. 2014. .  [PubMed]  [DOI]  [Cited in This Article: ]
15.  U.S. Food and Drug Administration. Scientific Considerations in Demonstrating Biosimilarity to a Reference Product. 2015.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
16.  Kuhlmann M, Covic A. The protein science of biosimilars. Nephrol Dial Transplant. 2006;21 Suppl 5:v4-v8.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 72]  [Cited by in F6Publishing: 61]  [Article Influence: 4.8]  [Reference Citation Analysis (0)]
17.  Morrow T, Felcone LH. Defining the difference: What Makes Biologics Unique. Biotechnol Healthc. 2004;1:24-29.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 77]  [Cited by in F6Publishing: 64]  [Article Influence: 8.6]  [Reference Citation Analysis (0)]
18.  Weise M, Kurki P, Wolff-Holz E, Bielsky MC, Schneider CK. Biosimilars: the science of extrapolation. Blood. 2014;124:3191-3196.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 184]  [Cited by in F6Publishing: 164]  [Article Influence: 23.0]  [Reference Citation Analysis (0)]
19.  European Medicines Agency. Remicade (infliximab). Summary of product Characteristics. Eur Med Agency. 2014;.  [PubMed]  [DOI]  [Cited in This Article: ]
20.  Remicade Dosing. Janssen Biotech, Inc.2016 [cited 2016-04-02];.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
21.  Committee for Medicinal Products for Human Use. Guideline on similar biological medicinal products containing monoclonal antibodies - non-clinical and clinical issues Guideline on Similar Biological Medicinal Products Containing Monoclonal Antibodies - Non-clinical and Clinical Issues Table of contents. 2014.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
22.  U.S. Food and Drug Administration. Biologics Price Competition and Innovation Act. 2009.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
23.  Alten R, Cronstein BN. Clinical trial development for biosimilars. Semin Arthritis Rheum. 2015;44:S2-S8.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 51]  [Cited by in F6Publishing: 39]  [Article Influence: 7.3]  [Reference Citation Analysis (0)]
24.  The Arrival of Biosimilar Therapies Heal Gastroenterol. 2016; Available from:{f37035aa-1129-42cd-beff-eeb8b3b220e5}/the-arrival-of-biosimilar-therapies.  [PubMed]  [DOI]  [Cited in This Article: ]
25.  Al-Sabbagh A, Olech E, Mcclellan JE, Kirchhoff CF. Development of biosimilars. Semin Arthritis Rheum. 2016;45:S11-S118.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 25]  [Cited by in F6Publishing: 21]  [Article Influence: 4.2]  [Reference Citation Analysis (0)]
26.  Blackstone EA, Joseph PF. The economics of biosimilars. Am Health Drug Benefits. 2013;6:469-478.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 19]  [Cited by in F6Publishing: 1]  [Article Influence: 2.4]  [Reference Citation Analysis (0)]
27.  Lehman B. The Pharmaceutical Industry and the Patent System. 2003;1-14 Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
28.  U.S. Food and Drug Administration. FDA approves Inflectra, a biosimilar to Remicade. 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
29.  Amgen. FDA Approves Amgen’s AMJEVITA (Adalimumab-Atto) For Treatment of Seven Inflammatory Diseases. 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
30.  Shih DQ, Targan SR. Insights into IBD Pathogenesis. Curr Gastroenterol Rep. 2009;11:473-480.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 56]  [Cited by in F6Publishing: 53]  [Article Influence: 4.7]  [Reference Citation Analysis (0)]
31.  Ordás I, Mould DR, Feagan BG, Sandborn WJ. Anti-TNF monoclonal antibodies in inflammatory bowel disease: pharmacokinetics-based dosing paradigms. Clin Pharmacol Ther. 2012;91:635-646.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 321]  [Cited by in F6Publishing: 284]  [Article Influence: 32.1]  [Reference Citation Analysis (0)]
32.  Teillaud JL. Antibody-dependent Cellular Cytotoxicity (ADCC). In: eLS. Chichester, UK: John Wiley & Sons, Ltd; 2012.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
33.  Pierri CL, Bossis F, Punzi G, De Grassi A, Cetrone M, Parisi G, Tricarico D. Molecular modeling of antibodies for the treatment of TNFα-related immunological diseases. Pharmacol Res Perspect. 2016;4:e00197.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 14]  [Cited by in F6Publishing: 14]  [Article Influence: 2.3]  [Reference Citation Analysis (0)]
34.  Feagan BG, Choquette D, Ghosh S, Gladman DD, Ho V, Meibohm B, Zou G, Xu Z, Shankar G, Sealey DC. The challenge of indication extrapolation for infliximab biosimilars. Biologicals. 2014;42:177-183.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 106]  [Cited by in F6Publishing: 85]  [Article Influence: 13.3]  [Reference Citation Analysis (0)]
35.  European Medicines Agency. EPAR summary for the public: Remsima. 2013.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
36.  Le J. Overview of Pharmacokinetics. Merck Man. 2016; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
37.  Zhao L, Ren TH, Wang DD. Clinical pharmacology considerations in biologics development. Acta Pharmacol Sin. 2012;33:1339-1347.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 55]  [Cited by in F6Publishing: 47]  [Article Influence: 5.5]  [Reference Citation Analysis (0)]
38.  Park W, Lee SJ, Yun J, Yoo DH. Comparison of the pharmacokinetics and safety of three formulations of infliximab (CT-P13, EU-approved reference infliximab and the US-licensed reference infliximab) in healthy subjects: a randomized, double-blind, three-arm, parallel-group, single-dose, Phase I study. Expert Rev Clin Immunol. 2015;11 Suppl 1:S25-S31.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 34]  [Cited by in F6Publishing: 12]  [Article Influence: 5.7]  [Reference Citation Analysis (0)]
39.  Kuhlmann MK, Goldsmith D, Covic A. Biosimilars. Int J Pharm Med. 2007;21:199-206.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 4]  [Cited by in F6Publishing: 4]  [Article Influence: 0.3]  [Reference Citation Analysis (0)]
40.  Bendtzen K. Immunogenicity of Anti-TNF-α Biotherapies: I. Individualized Medicine Based on Immunopharmacological Evidence. Front Immunol. 2015;6:152.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 15]  [Cited by in F6Publishing: 14]  [Article Influence: 2.1]  [Reference Citation Analysis (0)]
41.  Schellekens H. Bioequivalence and the immunogenicity of biopharmaceuticals. Nat Rev Drug Discov. 2002;1:457-462.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 367]  [Cited by in F6Publishing: 319]  [Article Influence: 18.4]  [Reference Citation Analysis (0)]
42.  Yarur AJ, Abreu MT, Deshpande AR, Kerman DH, Sussman DA. Therapeutic drug monitoring in patients with inflammatory bowel disease. World J Gastroenterol. 2014;20:3475-3484.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 41]  [Cited by in F6Publishing: 39]  [Article Influence: 5.1]  [Reference Citation Analysis (0)]
43.  Colombel JF, Sandborn WJ, Reinisch W, Mantzaris GJ, Kornbluth A, Rachmilewitz D, Lichtiger S, D’Haens G, Diamond RH, Broussard DL. Infliximab, azathioprine, or combination therapy for Crohn’s disease. N Engl J Med. 2010;362:1383-1395.  [PubMed]  [DOI]  [Cited in This Article: ]
44.  Panaccione R, Ghosh S, Middleton S, Márquez JR, Scott BB, Flint L, van Hoogstraten HJ, Chen AC, Zheng H, Danese S. Combination therapy with infliximab and azathioprine is superior to monotherapy with either agent in ulcerative colitis. Gastroenterology. 2014;146:392-400.e3.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 512]  [Cited by in F6Publishing: 445]  [Article Influence: 64.0]  [Reference Citation Analysis (0)]
45.  Feagan BG, McDonald JW, Panaccione R, Enns RA, Bernstein CN, Ponich TP, Bourdages R, Macintosh DG, Dallaire C, Cohen A. Methotrexate in combination with infliximab is no more effective than infliximab alone in patients with Crohn’s disease. Gastroenterology. 2014;146:681-688.e1.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 200]  [Cited by in F6Publishing: 170]  [Article Influence: 22.2]  [Reference Citation Analysis (0)]
46.  Yoo DH, Prodanovic N, Jaworski J, Miranda P, Ramiterre E, Lanzon A, Baranauskaite A, Wiland P, Abud-Mendoza C, Oparanov B. Efficacy and safety of CT-P13 (biosimilar infliximab) in patients with rheumatoid arthritis: comparison between switching from reference infliximab to CT-P13 and continuing CT-P13 in the PLANETRA extension study. Ann Rheum Dis. 2017;76:355-363.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 175]  [Cited by in F6Publishing: 154]  [Article Influence: 29.2]  [Reference Citation Analysis (0)]
47.  Observations on Trends in Prescription Drug Spending. ASPE Issue Br. 2016;1-16 Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
48.  Abo T. [Inflammatory bowel diseases]. Nihon Rinsho. 2004;62 Suppl 5:540-544.  [PubMed]  [DOI]  [Cited in This Article: ]
49.  Gibson TB, Ng E, Ozminkowski RJ, Wang S, Burton WN, Goetzel RZ, Maclean R. The direct and indirect cost burden of Crohn’s disease and ulcerative colitis. J Occup Environ Med. 2008;50:1261-1272.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 131]  [Cited by in F6Publishing: 52]  [Article Influence: 10.1]  [Reference Citation Analysis (0)]
50.  Jha A, Upton A, Dunlop WC, Akehurst R. The Budget Impact of Biosimilar Infliximab (Remsima®) for the Treatment of Autoimmune Diseases in Five European Countries. Adv Ther. 2015;32:742-756.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 103]  [Cited by in F6Publishing: 97]  [Article Influence: 14.7]  [Reference Citation Analysis (0)]
51.  Brodszky V, Baji P, Balogh O, Péntek M. Budget impact analysis of biosimilar infliximab (CT-P13) for the treatment of rheumatoid arthritis in six Central and Eastern European countries. Eur J Health Econ. 2014;15 Suppl 1:S65-S71.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 89]  [Cited by in F6Publishing: 84]  [Article Influence: 11.1]  [Reference Citation Analysis (0)]
52.  IMS Institute for Healthcare Informatics. Shaping the biosimilars opportunity: A global perspective on the evolving biosimilars landscape. IMS Heal. 2011;1-7 Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
53.  U.S. Food and Drug Administration. FDA approves first biosimilar product Zarxio. 2015.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
54.  Fuhr JP. Biosimilars Can Save Lives And Cost Less. Forbes. 2014; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
55.  Miller S. The $250 Billion Potential of Biosimilars. Express Scripts. 2013;1-3 Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
56.  Putrik P, Ramiro S, Kvien TK, Sokka T, Pavlova M, Uhlig T, Boonen A. Inequities in access to biologic and synthetic DMARDs across 46 European countries. Ann Rheum Dis. 2014;73:198-206.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 199]  [Cited by in F6Publishing: 188]  [Article Influence: 22.1]  [Reference Citation Analysis (0)]
57.  Khraishi M, Stead D, Lukas M, Scotte F, Schmid H. Biosimilars: A Multidisciplinary Perspective. Clin Ther. 2016;38:1238-1249.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 22]  [Cited by in F6Publishing: 17]  [Article Influence: 3.7]  [Reference Citation Analysis (0)]
58.  Sandborn WJ, Hanauer SB, Katz S, Safdi M, Wolf DG, Baerg RD, Tremaine WJ, Johnson T, Diehl NN, Zinsmeister AR. Etanercept for active Crohn’s disease: a randomized, double-blind, placebo-controlled trial. Gastroenterology. 2001;121:1088-1094.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 636]  [Cited by in F6Publishing: 543]  [Article Influence: 30.3]  [Reference Citation Analysis (0)]
59.  Van den Brande JM, Braat H, van den Brink GR, Versteeg HH, Bauer CA, Hoedemaeker I, van Montfrans C, Hommes DW, Peppelenbosch MP, van Deventer SJ. Infliximab but not etanercept induces apoptosis in lamina propria T-lymphocytes from patients with Crohn’s disease. Gastroenterology. 2003;124:1774-1785.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 531]  [Cited by in F6Publishing: 125]  [Article Influence: 27.9]  [Reference Citation Analysis (0)]
60.  Smeets TJ, Kraan MC, van Loon ME, Tak PP. Tumor necrosis factor alpha blockade reduces the synovial cell infiltrate early after initiation of treatment, but apparently not by induction of apoptosis in synovial tissue. Arthritis Rheum. 2003;48:2155-2162.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 144]  [Cited by in F6Publishing: 149]  [Article Influence: 7.6]  [Reference Citation Analysis (0)]
61.  Park W, Hrycaj P, Jeka S, Kovalenko V, Lysenko G, Miranda P, Mikazane H, Gutierrez-Ureña S, Lim M, Lee YA. A randomised, double-blind, multicentre, parallel-group, prospective study comparing the pharmacokinetics, safety, and efficacy of CT-P13 and innovator infliximab in patients with ankylosing spondylitis: the PLANETAS study. Ann Rheum Dis. 2013;72:1605-1612.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 410]  [Cited by in F6Publishing: 351]  [Article Influence: 45.6]  [Reference Citation Analysis (0)]
62.  Yoo DH, Hrycaj P, Miranda P, Ramiterre E, Piotrowski M, Shevchuk S, Kovalenko V, Prodanovic N, Abello-Banfi M, Gutierrez-Ureña S. A randomised, double-blind, parallel-group study to demonstrate equivalence in efficacy and safety of CT-P13 compared with innovator infliximab when coadministered with methotrexate in patients with active rheumatoid arthritis: the PLANETRA study. Ann Rheum Dis. 2013;72:1613-1620.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 444]  [Cited by in F6Publishing: 379]  [Article Influence: 49.3]  [Reference Citation Analysis (0)]
63.  Park W, Yoo DH, Jaworski J, Brzezicki J, Gnylorybov A, Kadinov V, Sariego IG, Abud-Mendoza C, Escalante WJ, Kang SW. Comparable long-term efficacy, as assessed by patient-reported outcomes, safety and pharmacokinetics, of CT-P13 and reference infliximab in patients with ankylosing spondylitis: 54-week results from the randomized, parallel-group PLANETAS study. Arthritis Res Ther. 2016;18:25.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 94]  [Cited by in F6Publishing: 85]  [Article Influence: 15.7]  [Reference Citation Analysis (0)]
64.  Summary Basis of Decision (SBD): Remsima. Heal Canada 2015.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
65.  U.S. Food and Drug Administration. Arthritis Advisory Committee Meeting: CT-P13. 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
66.  World Health Organization (WHO). Guidelines on evaluation of similar biotherapeutic products (SBPs). 2009. 19-23 Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
67.  Biosimilar switching not suitable for all patients. London, United Kingdom: 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
68.  Seow CH, Newman A, Irwin SP, Steinhart AH, Silverberg MS, Greenberg GR. Trough serum infliximab: a predictive factor of clinical outcome for infliximab treatment in acute ulcerative colitis. Gut. 2010;59:49-54.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 394]  [Cited by in F6Publishing: 362]  [Article Influence: 32.8]  [Reference Citation Analysis (0)]
69.  PR Newswire. Prometheus Diagnostic Test Validated in Anticipation of U.S. Healthcare Provider Demand for Celltrion’s INFLECTRATM (Biosimilar Infliximab). 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
70.  Singh SC, Bagnato KM. The economic implications of biosimilars. Am J Manag Care. 2015;21:s331-s340.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2]  [Cited by in F6Publishing: 1]  [Article Influence: 0.4]  [Reference Citation Analysis (0)]
71.  Warren WL, Fang L, Goron K. Abbreviated approval of generic biologics. Genet Eng News. 2006;26:9-10 Available from: KbDtRr9tObDdEuSpCp0!/ legal-warren-final21.pdf.  [PubMed]  [DOI]  [Cited in This Article: ]
72.  Wang J, Chow SC. On the regulatory approval pathway of biosimilar products. Pharmaceuticals (Basel). 2012;5:353-368.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 55]  [Cited by in F6Publishing: 43]  [Article Influence: 5.5]  [Reference Citation Analysis (0)]
73.  Mulcahy A, Predmore Z, Mattke S, States U. The Cost Savings Potential of Biosimilar Drugs in the United States. RAND Corp. 2014; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
74.  U.S. Food and Drug Administration. Information for Healthcare Professionals (Biosimilars). U.S. Dep Heal Hum Serv. 2015; Available from: Approved/ApprovalApplications/TherapeuticBiologic Applications/Biosimilars/ucm241719.htm.  [PubMed]  [DOI]  [Cited in This Article: ]
75.  Blackstone EA, Fuhr JP. Innovation and Competition: Will Biosimilars Succeed?: The creation of an FDA approval pathway for biosimilars is complex and fraught with hazard. Yes, innovation and market competition are at stake. But so are efficacy and patient safety. Biotechnol Healthc. 2012;9:24-27.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 7]  [Cited by in F6Publishing: 1]  [Article Influence: 0.7]  [Reference Citation Analysis (0)]
76.  Cauchi R. State Laws and Legislation Related to Biologic Medications and Substitution of Biosimilars. Natl Conf State Legis. 2016; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
77.  Reinisch W, Smolen J. Biosimilar safety factors in clinical practice. Semin Arthritis Rheum. 2015;44:S9-S15.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 27]  [Cited by in F6Publishing: 22]  [Article Influence: 3.9]  [Reference Citation Analysis (0)]
78.  Danese S, Fiorino G, Raine T, Ferrante M, Kemp K, Kierkus J, Lakatos PL, Mantzaris G, van der Woude J, Panes J. ECCO Position Statement on the Use of Biosimilars for Inflammatory Bowel Disease-An Update. J Crohns Colitis. 2017;11:26-34.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 130]  [Cited by in F6Publishing: 108]  [Article Influence: 21.7]  [Reference Citation Analysis (0)]
79.  Aquino JT. FDA Extends Wait for Biosimilar Interchangeability Guidance. Bloom. BNA 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
80.  European Medicines Agency. European Medicines Agency recommends approval of first two monoclonal antibody biosimilars. 2013.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
81.  Murphy C, Sugrue K, Mohamad G, McCarthy J, Buckley M. P505. Biosimilar but not the same. J Crohns Colitis. 2015;9:S331-S332.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 7]  [Cited by in F6Publishing: 6]  [Article Influence: 1.0]  [Reference Citation Analysis (0)]
82.  Jung YS, Park DI, Kim YH, Lee JH, Seo PJ, Cheon JH, Kang HW, Kim JW. Efficacy and safety of CT-P13, a biosimilar of infliximab, in patients with inflammatory bowel disease: A retrospective multicenter study. J Gastroenterol Hepatol. 2015;30:1705-1712.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 112]  [Cited by in F6Publishing: 98]  [Article Influence: 18.7]  [Reference Citation Analysis (0)]
83.  Celltrion Healthcare: Patients feel the benefit of biosimilar infliximab in Europe. Bus Wire. 2015; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
84.  Jahnsen J, Detlie TE, Vatn S, Ricanek P. Biosimilar infliximab (CT-P13) in the treatment of inflammatory bowel disease: A Norwegian observational study. Expert Rev Gastroenterol Hepatol. 2015;9 Suppl 1:45-52.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 73]  [Cited by in F6Publishing: 59]  [Article Influence: 12.2]  [Reference Citation Analysis (0)]
85.  Gecse KB, Lovász BD, Farkas K, Banai J, Bene L, Gasztonyi B, Golovics PA, Kristóf T, Lakatos L, Csontos ÁA, Juhász M, Nagy F, Palatka K, Papp M, Patai Á, Lakner L, Salamon Á, Szamosi T, Szepes Z, Tóth GT, Vincze Á, Szalay B, Molnár T, Lakatos PL. Efficacy and Safety of the Biosimilar Infliximab CT-P13 Treatment in Inflammatory Bowel Diseases: A Prospective, Multicentre, Nationwide Cohort. J Crohns Colitis. 2016;10:133-140.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 130]  [Cited by in F6Publishing: 109]  [Article Influence: 18.6]  [Reference Citation Analysis (0)]
86.  Sieczkowska J, Jarzebicka D, Banaszkiewicz A, Plocek A, Gawronska A, Toporowska-Kowalska E, Kierkus J. Assessment of safety and efficacy of biosimilar infliximab in children with Crohn disease: A preliminary report. J Crohns Colitis. 2015;9:S295.  [PubMed]  [DOI]  [Cited in This Article: ]
87.  Smits LJ, Derikx LA, de Jong DJ, Boshuizen RS, van Esch AA, Drenth JP, Hoentjen F. Clinical Outcomes Following a Switch from Remicade® to the Biosimilar CT-P13 in Inflammatory Bowel Disease Patients: A Prospective Observational Cohort Study. J Crohns Colitis. 2016;10:1287-1293.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 102]  [Cited by in F6Publishing: 92]  [Article Influence: 17.0]  [Reference Citation Analysis (0)]
88.  The NOR-SWITCH Study (NOR-SWITCH). 2015 [cited 2016-03-22].  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
89.  Celltrion Healthcare Showcases Data Supporting Efficacy and Safety of Both CT-P10 and CT-P13 Biosimilars. Bus Wire. 2016; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
90.  Biogen. FLIXABI®, Biogen’s Infliximab Biosimilar Referencing Remicade®, Approved in the European Union. 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
91.  Choe JY, Prodanovic N, Niebrzydowski J, Staykov I, Dokoupilova E, Baranauskaite A, Yatsyshyn R, Mekic M, Porawska W, Ciferska H. A randomised, double-blind, phase III study comparing SB2, an infliximab biosimilar, to the infliximab reference product Remicade in patients with moderate to severe rheumatoid arthritis despite methotrexate therapy. Ann Rheum Dis. 2017;76:58-64.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 107]  [Cited by in F6Publishing: 95]  [Article Influence: 15.3]  [Reference Citation Analysis (0)]
92.  Sandoz strengthens its biosimilars portfolio with acquisition of Pfizer’s biosimilar infliximab in EEA. Novartis. 2016; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
93.  Udata C, Hua SY, Yin D, Salts S, Meng X, Rehman MI. FRI0301 A Phase I Pharmacokinetics TRIAL Comparing PF-06438179 (A Potential Biosimilar) and Infliximab in Healthy Volunteers (Reflections B537-01). Ann Rheum Dis. 2014;73:494.1-494.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 3]  [Cited by in F6Publishing: 1]  [Article Influence: 0.4]  [Reference Citation Analysis (0)]
94.  A Study of PF-06438179 (Infliximab-Pfizer) and Infliximab in Combination With Methotrexate in Subjects With Active Rheumatoid Arthritis (REFLECTIONS B537-02). 2016.  Available from: https: //  [PubMed]  [DOI]  [Cited in This Article: ]
95.  Rajan C. Epirus’s Biosimilar Arthritis Drug Wins Approval in India. Bioprocess Online. 2014; Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
96.  BOW015 (Infliximab-EPIRUS) and Infliximab in Patients With Active Rheumatoid Arthritis: The UNIFORM Study. 2016.  Available from: https: //  [PubMed]  [DOI]  [Cited in This Article: ]
97.  PR Newswire. Amgen’s First Biosimilar Biologics License Application For ABP 501 Submitted To U.S. Food And Drug Administration. 2015.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
98.  PR Newswire. Amgen Presents Detailed Results From Phase 3 Study Demonstrating Clinical Equivalence Of Biosimilar Candidate ABP 501 With Adalimumab. 2015.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
99.  Amgen. Amgen Announces Positive Top-Line Results From Phase 3 Study Evaluating The Efficacy And Safety Of Biosimilar Candidate ABP 501 Compared With Adalimumab In Patients With Moderate-To-Severe Plaque Psoriasis. 2014.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
100.  PR Newswire. Zydus Launches World’s First Biosimilar of Adalimumab. 2014.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
101.  Jani RH, Gupta R, Bhatia G, Rathi G, Ashok Kumar P, Sharma R, Kumar U, Gauri LA, Jadhav P, Bartakke G. A prospective, randomized, double-blind, multicentre, parallel-group, active controlled study to compare efficacy and safety of biosimilar adalimumab (Exemptia; ZRC-3197) and adalimumab (Humira) in patients with rheumatoid arthritis. Int J Rheum Dis. 2016;19:1157-1168.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 47]  [Cited by in F6Publishing: 24]  [Article Influence: 6.7]  [Reference Citation Analysis (0)]
102.  MSB11022 in Moderate to Severe Chronic Plaque Psoriasis (AURIEL-PsO). 2016.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
103.  Silver S. Industry Surveys: Biotechnology. New York: 2013.  Available from:  [PubMed]  [DOI]  [Cited in This Article: ]
104.  Sieczkowska J, Jarzębicka D, Banaszkiewicz A, Plocek A, Gawronska A, Toporowska-Kowalska E, Oracz G, Meglicka M, Kierkus J. Switching Between Infliximab Originator and Biosimilar in Paediatric Patients with Inflammatory Bowel Disease. Preliminary Observations. J Crohns Colitis. 2016;10:127-132.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 91]  [Cited by in F6Publishing: 82]  [Article Influence: 13.0]  [Reference Citation Analysis (0)]