The Automatic Substitution of Biosimilars: Definitions of Interchangeability are not Interchangeable

Use of Biosimilars: A Systematic Review of Published Position Statements and Recommendations from Health Organisations and Societies

BACKGROUND

Hesitation about using biosimilars still exists among healthcare professionals (HCPs), despite extensive experience with their use. Globally, several health organisations and societies from various specialties have issued biosimilar position statements to guide the use of biosimilars in their specialties. However, it is uncertain how similar or different their positions or recommendations are or whether these positions have evolved with the increased experience and availability of new evidence.

OBJECTIVES

The study aimed to describe and assess the recommendations of published position statements regarding several aspects of biosimilars across specialties and determine whether these positions have changed with the emergence of new evidence.

METHODS

We systematically searched for published position statements of biosimilars in online databases and included statements written in English. The search was from the inception of the databases until May 2023. Two reviewers independently extracted the data. Only position statements that included recommendations to guide the use of biosimilars in clinical practice and were issued by health organisations and societies, including expert panels, were included. We synthesised recommendations on five aspects: prescribing practice, extrapolation of indication, interchangeability, treatment initiation with biosimilars in biologic-naïve patients, and pharmacovigilance.

RESULTS

The review included 25 papers involving eight specialties, 16 of which were from European countries, 1 from an international organisation representing 49 countries, and 6 from various countries. The papers were published between 2009 and 2020, with 19 published between 2015 and 2020. Of the five aspects of biosimilars assessed, nearly half (11 of 25) of the papers at the time they were published did not base their positions on a scientific or evidence-based approach. Only 4 of the 25 position papers were identified as revisions of their previous papers. With increasing experience in biosimilars and the emergence of new evidence, about 60% (16 of 25) of the papers contained outdated recommendations, particularly on two aspects. They were extrapolations of indications and interchangeability (including switching). The recommendations for most papers for three other aspects were still appropriate. These were prescribing biosimilars by their brand name and active ingredient, initiating treatment with biosimilars in biologic-naïve patients, and monitoring the long-term safety of biosimilars through pharmacovigilance. For four of the revised papers, their position evolved from opposing indication extrapolation for biosimilars to accepting it, while the position of two papers shifted from not recommending biosimilar switching to permitting the practice. Meanwhile, most papers were against automatic substitution by pharmacists because the evidence for this practice was still limited.

CONCLUSIONS

Across specialties, the variability among the position statements is seen for extrapolation of indications for biosimilars and interchangeability (including switching). This requires a revision, considering the latest evidence and growing experience with the use of biosimilars in extrapolated indications and with switching.

An Overview of Biosimilars-Development, Quality, Regulatory Issues, and Management in Healthcare

Biological therapies have transformed high-burden treatments. As the patent and exclusivity period for biological medicines draws to a close, there is a possibility for the development and authorization of biosimilars. These products boast comparable levels of safety, quality, and effectiveness to their precursor reference products. Biosimilars, although similar to reference products, are not identical copies and should not be considered generic substitutes for the original. Their development and evaluation involve a rigorous step-by-step process that includes analytical, functional, and nonclinical evaluations and clinical trials. Clinical studies conducted for biosimilars aim to establish similar efficacy, safety, and immunogenicity, rather than demonstrating a clinical benefit, as with the reference product. However, although the current knowledge regarding biosimilars has significantly increased, several controversies and misconceptions still exist regarding their immunogenicity, extrapolation, interchangeability, substitution, and nomenclature. The development of biosimilars stimulates market competition, contributes toward healthcare sustainability, and allows for greater patient access. However, maximizing the benefits of biosimilars requires cooperation between regulators and developers to ensure that patients can benefit quickly from access to these new therapeutic alternatives while maintaining high standards of quality, safety, and efficacy. Recognizing the inherent complexities of comprehending biosimilars fully, it is essential to focus on realistic approaches, such as fostering open communication between healthcare providers and patients, encouraging informed decision-making, and minimizing risks. This review addresses the regulatory and manufacturing requirements for biosimilars and provides clinicians with relevant insights for informed prescribing.

Exploring the Influence of Health Insurance Plans on Biosimilar Adoption Rates

BACKGROUND

We conducted a study to investigate the role of health insurance plans on biosimilar adoption among commercially insured patients in the USA. Flexible and rigid health plans may exhibit differing biosimilar coverage due to variations in cost considerations, formulary design, and provider networks.

OBJECTIVE

To identify the characteristics of switchers and biosimilar initiators for six biologic-biosimilar pairs.

METHODS

Using claims data from 2015 to 2019, we implement sequential regression models to assess the role of health plans on biosimilars adoption.

FINDINGS

We found that low-flexibility plans, such as Health Maintenance Organization (HMOs) and Exclusive Provider Organization (EPOs), are more likely to have patients who are switchers and/or biosimilar initiators.

CONCLUSION

Our findings highlight the importance of health insurance plan design in promoting biosimilar uptake.

Assessment of Reported Adverse Events After Interchanging Between TNF-α Inhibitor Biosimilars in the WHO Pharmacovigilance Database

BACKGROUND AND OBJECTIVE

Observational studies have shown that a significant proportion of patients interchanging between tumor necrosis factor-α inhibitor biosimilars withdraws from the new treatment because of adverse effects. We aim to analyze adverse events related to interchanging from tumor necrosis factor-α (TNF-α) inhibitor reference products to biosimilars and between biosimilars reported in the World Health Organization pharmacovigilance database.

METHODS

We extracted all cases reporting the Medical Dictionary for Regulatory Activities term "Product substitution issue (PT)" for TNF-α inhibitors. Then, we analyzed and categorized all adverse events reported in more than 1% of cases. We compared the adverse events reported according to reporter qualification, type of switch, and type of TNF-α inhibitor using Chi2 tests. We conducted a network analysis coupled with a clustering approach to identify syndromes of co-reported adverse events.

RESULTS

In the World Health Organization pharmacovigilance database, 2543 cases and 6807 adverse events related to TNF-α inhibitor interchangeability have been reported up to October 2022. Injection-site reactions were the most reported adverse events with 940 cases (37.0%), followed by modifications in drug effect in 607 cases (23.9%). Musculoskeletal, cutaneous, and gastrointestinal disorders linked to the underlying disease were reported in 505 (20.0%), 145 (5.7%), and 207 (8.1%) cases, respectively. Adverse events non-related to the underlying disease were nonspecific (n = 458, 18.0%), neurologic (n = 224, 8.8%), respiratory (n = 132, 5.2%), and psychological disorders (n = 64, 2.5%). Injection-site reactions and infection-related symptoms (e.g., nasopharyngitis, urinary tract infection, lower respiratory tract infection) were more reported by non-healthcare professionals while adverse events related to reduced clinical efficacy (e.g., drug ineffective, arthralgia, psoriasis) were more reported by healthcare professionals. The proportions of injection-site reactions were higher when switching between biosimilars of the same reference product, but the proportions of adverse events related to reduced clinical efficacy (e.g., psoriasis, arthritis, psoriatic arthropathy) were more reported when switching from a reference product. The main differences in the proportions of reported cases between adalimumab, infliximab, and etanercept were driven by symptoms related to the underlying targeted diseases, except for a higher reporting rate of injection-site pain with adalimumab. Adverse events evocative of hypersensitivity reactions were reported in 192 (7.6%) cases. Most of the network clusters concerned non-specific adverse events or were related to reduced clinical efficacy.

CONCLUSIONS

This analysis highlights the burden of patient-reported adverse events when interchanging between TNF-α inhibitor biosimilars, notably injection-site reactions, non-specific adverse events, and symptoms related to reduced clinical efficacy. Our study also highlights differences in reporting patterns between patients and healthcare professionals and depending on the type of switch. The results are limited by missing data, the lack of precision of the coded Medical Dictionary for Regulatory Activities terms, and by the variability of reporting rate of adverse events. Thus, incidence rates of adverse events cannot be inferred from these results.

An international comparative analysis and roadmap to sustainable biosimilar markets

Background: Although biosimilar uptake has increased (at a variable pace) in many countries, there have been recent concerns about the long-term sustainability of biosimilar markets. The aim of this manuscript is to assess the sustainability of policies across the biosimilar life cycle in selected countries with a view to propose recommendations for supporting biosimilar sustainability. Methods: The study conducted a comparative analysis across 17 countries from North America, South America, Asia-Pacific, Europe and the Gulf Cooperation Council. Biosimilar policies were identified and their sustainability was assessed based on country-specific reviews of the scientific and grey literature, validation by industry experts and 23 international and local non-industry experts, and two advisory board meetings with these non-industry experts. Results: Given that European countries tend to have more experience with biosimilars and more developed policy frameworks, they generally have higher sustainability scores than the other selected countries. Existing approaches to biosimilar manufacturing and R&D, policies guaranteeing safe and high-quality biosimilars, exemption from the requirement to apply health technology assessment to biosimilars, and initiatives counteracting biosimilar misconceptions are considered sustainable. However, biosimilar contracting approaches, biosimilar education and understanding can be ameliorated in all selected countries. Also, similar policies are sometimes perceived to be sustainable in some markets, but not in others. More generally, the sustainability of the biosimilar landscape depends on the nature of the healthcare system and existing pharmaceutical market access policies, the experience with biosimilar use and policies. This suggests that a general biosimilar policy toolkit that ensures sustainability does not exist, but varies from country to country. Conclusion: This study proposes a set of elements that should underpin sustainable biosimilar policy development over time in a country. At first, biosimilar policies should guarantee the safety and quality of biosimilars, healthy levels of supply and a level of cost savings. As a country gains experience with biosimilars, policies need to optimise uptake and combat any misconceptions about biosimilars. Finally, a country should implement biosimilar policies that foster competition, expand treatment options and ensure a sustainable market environment.

Impact of switching between reference biologics and biosimilars of tumour necrosis factor inhibitors for rheumatoid arthritis: a systematic review and network meta-analysis

What is the impact of switching between biologics and biosimilars of adalimumab, etanercept, and infliximab on efficacy and safety for rheumatoid arthritis? A systematic review and network meta-analysis were performed to compare switching and non-switching groups of treatments. Pooled Risk Relative (RR) or standardised mean differences (SMD) with 95% credible intervals (95% CrIs) were obtained. Seventeen randomized trials with a switching phase involving 6,562 patients were included. Results showed that a single switch from biologics to biosimilars compared to continuing biologics had comparable effects for primary and co-primary outcomes, the American College of Rheumatology criteria with 20% response (ACR20) (7 trials, 1,926 patients, RR 0.98, 95% CrIs 0.93 to 1.03) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) (5 trials, 1,609 patients, SMD - 0.07, 95% CrIs - 0.23 to 0.1), and within the equivalence margins: ACR20 [RR 0.94, 1.06] and HAQ-DI [SMD - 0.22, 0.22]. The risk of treatment-emergent adverse events, discontinuation, and positive anti-drug antibodies were comparable after switching. Safety results were imprecise, and the follow-up period might not be sufficient to evaluate long-term effects, especially malignancies. Overall, the practice of single switching between approved biologics and biosimilars of Tumour Necrosis Factor inhibitors is efficacious and safe for rheumatoid arthritis.

Assessing the Interchangeability of AVT02 and Humira® in Participants with Moderate‑to‑Severe Chronic Plaque Psoriasis: Pharmacokinetics, Efficacy, Safety, and Immunogenicity Results from a Multicenter, Double-Blind, Randomized, Parallel-Group Study

BACKGROUND

The US Food and Drug Administration (FDA) interchangeability guidelines state that the primary endpoint in a switching study should assess the impact of switching between the proposed interchangeable product and the reference product on clinical pharmacokinetics (PK) and pharmacodynamics (if available), as these assessments are generally sensitive to changes in immunogenicity and/or exposure that may arise due to switching. In addition, interchangeability designation requires no clinically meaningful difference in safety and efficacy of switching between the biosimilar and reference, compared with when using the reference product alone.

OBJECTIVES

 The aim of this study was to investigate the PK, immunogenicity, efficacy, and safety in participants undergoing repeated switches between Humira^® and AVT02 as part of a global interchangeable development program.

METHODS

This multicenter, randomized, double-blind, parallel-group study in patients with moderate-to-severe plaque psoriasis comprises three parts: lead-in period (weeks 1-12), switching module (weeks 12-28), and the optional extension phase (weeks 28-52). Following the lead-in period during which all participants received the reference product (80 mg in week 1, followed by 40 mg every other week), participants with a clinical response of ≥ 75% improvement in the Psoriasis Area and Severity Index (PASI75) were randomized 1:1 to receive AVT02 alternating with the reference product (switching arm) or reference product only (non-switching arm). At week 28, participants who were PASI50 responders could opt to take part in an open-label extension phase receiving AVT02 up to week 50, with an end of study visit at week 52. PK, safety, immunogenicity, and efficacy were evaluated at various timepoints throughout the study for both switching and non-switching arms.

RESULTS

In total, 550 participants were randomized to switching (277) and non-switching arms (273). The switching versus non-switching arithmetic least square means ratio [90% confidence intervals (CIs)] was 101.7% (91.4-112.0%) for the area under the concentration-time curve over the dosing interval from weeks 26-28 (AUC_{tau, W26-28}) and 108.1% (98.3-117.9%) for maximum concentration over the dosing interval from weeks 26-28 (C_{max, W26-28}). The 90% CIs for the switching versus non-switching arithmetic means ratio for primary endpoints AUC_{tau, W26-28} and C_{max, W26-28} were within the prespecified limits of 80-125%, demonstrating comparable PK profiles between groups. In addition, the PASI, Dermatology Life Quality Index, and static Physician's Global Assessment efficacy scores were highly similar for both treatment groups. There were no clinically meaningful differences between the immunogenicity and safety assessments of repeated switching between AVT02 and the reference product, versus the reference product alone.

CONCLUSIONS

This study demonstrated that the risk, in terms of safety or diminished efficacy of switching between the biosimilar and the reference product, is not greater than the risk of using the reference product alone, as required by the FDA for interchangeability designation. Beyond the scope of interchangeability, a consistent long-term safety and immunogenicity profile, with no impact on the trough levels up to 52 weeks, was established.

CLINICAL TRIAL REGISTRATION

NCT04453137; date of registration: 1 July 2020.

Identification of Barriers Preventing Biosimiliar Oncology Medication Adoption

(1) Background: A biosimilar is a biologic medical product that has been approved by the United States Food and Federal Drug Administration (FDA) and is an almost identical copy of an original biologic product yet manufactured by a different company. Biosimilars are often assumed to be the same as generic medications, while often made from living organisms. Through clinical trials, biosimilars have been shown to be both as safe and as effective as their originator products. Biosimilars have also proven they can reduce the costs to both insurance companies and patients in many circumstances. However, despite their cost savings, biosimilar manufacturers continue to face barriers in having oncologists and cancer centers prescribe them for their patients. This review aims to identify barriers associated with medical provider prescriptive behaviors related to biosimilars for patients. (2) Methods: Reviewers analyzed 27 articles and identified common themes. (3) Results: After a thorough literature review, the researchers identified seven barriers to prescribing of biosimilars: physician comfort in originators instead of biosimilars, patient reluctance to switch from a current biologic to a biosimilar, provider profits associated with an originator biologic, lack of stakeholder education on biosimilars, lack of provider team knowledge of biosimilars, lack of knowledge surrounding the biosimilar FDA approval process, and hesitancy to stock multiple drugs for a specific indication. (4) Conclusions: This review’s findings of identified barriers to use of biosimilars provides insight for healthcare providers and organizations surrounding prescribing practices and potential treatment benefits for cancer patients who may benefit from biosimilar treatment medications.

Under the Umbrella of Clinical Pharmacology: Inflammatory Bowel Disease, Infliximab and Adalimumab, and a Bridge to an Era of Biosimilars

Monoclonal antibodies (MAbs) have revolutionized the treatment of many chronic inflammatory diseases, including inflammatory bowel disease (IBD). IBD is a term that comprises two quite similar, yet distinctive, disorders—Crohn’s disease (CD) and ulcerative colitis (UC). Two blockbuster MAbs, infliximab (IFX) and adalimumab (ADL), transformed the pharmacological approach of treating CD and UC. However, due to the complex interplay of pharmacology and immunology, MAbs face challenges related to their immunogenicity, effectiveness, and safety. To ease the burden of IBD and other severe diseases, biosimilars have emerged as a cost-effective alternative to an originator product. According to the current knowledge, biosimilars of IFX and ADL in IBD patients are shown to be as safe and effective as their originators. The future of biosimilars, in general, is promising due to the potential of making the health care system more sustainable. However, their use is accompanied by misconceptions regarding their effectiveness and safety, as well as by controversy regarding their interchangeability. Hence, until a scientific consensus is achieved, scientific data on the long-term effectiveness and safety of biosimilars are needed.

Impact of switching to infliximab biosimilars on treatment patterns among US veterans receiving innovator infliximab

OBJECTIVE

To compare treatment patterns of United States (US) veterans stable on innovator infliximab (IFX) who switched to an IFX biosimilar (switchers) or remained on innovator IFX (continuers).

METHODS

US Veterans Healthcare Administration data (01/2012-12/2019) were used to identify adults with rheumatoid arthritis (RA), psoriatic arthritis (PsA), plaque psoriasis (PsO), ankylosing spondylitis (AS), or Crohn's disease and ulcerative colitis (i.e. inflammatory bowel disease [IBD]), treated with innovator or biosimilar IFX. Index date was the first IFX biosimilar administration for switchers or a random innovator IFX administration for continuers. Patients were required to have ≥5 innovator IFX administrations during the 12 months pre-index (prevalent population). Patients with ≥12 months of observation prior to the first innovator IFX administration were analyzed as the primary population (incident population), and data were assessed from start of innovator IFX. Inverse probability of treatment weighting was used to balance baseline characteristics between cohorts. Treatment patterns were evaluated post-index; continuers were censored before switching to IFX biosimilar. Discontinuation was defined as switching to another biologic (including innovator IFX) or having ≥120 days between 2 consecutive index treatment records.

RESULTS

In the incident population, mean [median] duration of follow-up was 737 [796] days among switchers (N = 838) and 479 [337] days among continuers (N = 849). Compared to continuers, switchers were 2.88-times more likely to discontinue index therapy (hazard ratio [HR] = 2.88, p < .001) and 4.99-times more likely to switch to another innovator biologic (HR = 4.99, p < .001). Of 653 switchers switching to another innovator biologic, 594 (91.0%) switched back to innovator IFX. Results were similar among the prevalent population and RA and IBD subgroups.

CONCLUSION

Patients switching from innovator to biosimilar IFX were more likely to discontinue treatment and switch to another innovator biologic (notably back to innovator IFX) than those remaining on innovator IFX; however, reasons for discontinuation and switching are unknown.

An Introduction to Biosimilars for the Treatment of Retinal Diseases: A Narrative Review

Biological therapies have revolutionized the treatment of disease across a number of therapeutic areas including retinal diseases. However, on occasion, such treatments may be relatively more expensive compared to small molecule therapies. This can restrict patient access and treatment length leading to suboptimal clinical outcomes. Several biosimilar candidates of ranibizumab and aflibercept are currently in development and the first biosimilar of ranibizumab received EMA approval in August and FDA approval in September 2021. Biosimilars are biological medicines that are highly similar to an already-approved biological medicine (reference product). The physicochemical and clinical similarity of a biosimilar is determined by a rigorous analytical and clinical program, including extensive pharmacokinetic and pharmacodynamic analysis with phase III equivalence studies where appropriate. These phase III studies are carried out in a patient population that is representative of all of the potential approved therapeutic indications of the originator product and the most sensitive for detecting potential differences between the biosimilar and the reference product. Biosimilars have been used successfully across a wide range of therapeutic areas for the past 15 years where they have achieved substantial cost savings that can be reinvested into healthcare systems without affecting the quality of patient care. The current review provides an introduction to biosimilars with the aim of preparing retinal specialists for discussing these products with their patients.

Patient-Reported Outcomes in Rheumatoid Arthritis: A Key Consideration for Evaluating Biosimilar Uptake?

Purpose

This review aims to provide an overview of the impact of TNFis biosimilars, with marketing authorization, in patient-reported outcome measures (PROMs) scores and explore how PROMs endpoints might add value in biosimilars uptake in RA patients.

Patients and Methods

A comprehensive search of Medline, Scopus, Lilacs, and CINAHL databases was performed for papers published between January 2012 and December 2021. For inclusion, studies had to be prospective, published in a peer-reviewed journal, published in English or Spanish language; studies using PROMs as an outcome measure. After screening title and abstracts and assessing the remaining full texts fulfilling the inclusion criteria, 31 papers were used in this narrative review.

Results

PROMs were used as secondary outcomes in included studies. The most frequently employed domains to assess biosimilar efficacy include physical function, patient global assessment (PtGA), health-related quality of life (HRQoL), and fatigue. The results of randomized clinical trials uniformly showed that mean change in PROMs scores is comparable between biosimilar and reference biologic treatment groups. However, open-label and real-world studies revealed high rates of discontinuation of therapy, mainly for subjective worsening of disease activity or non-specific adverse events. Even without objective clinical evidence of inflammation, patients who are considered to have active disease (higher scores on PtGA) have higher discontinuation rates of biosimilars. The available information suggests that the nocebo effect is the most likely cause for the discontinuation of biosimilars.

Conclusion

There is scarce literature surrounding the impact of biosimilars in PROMs, especially in open-label studies. In real-life studies, biosimilars have a higher discontinuation rate than reference products. TNFis biosimilars treatment efficacy in RA depends on disease activity and other factors such as PtGA and fatigue. The nocebo effect is the best explanation for biosimilar’s discontinuation.

Is There Any Research Evidence Beyond Surveys and Opinion Polls on Automatic Substitution of Biological Medicines? A Systematic Review

Background

Biosimilars are expected to decrease growing health care expenditures. Given that uptake of biosimilars has been modest, automatic substitution has been suggested to increase their use, but the practice is not yet allowed or implemented in many jurisdictions.

Methods

A systematic review was performed by searching databases Scopus, Medline (Ovid), CINAHL, and Web of Science. Peer-reviewed, original studies written in English and published during the period January 1, 2006 to April 24, 2021 reporting any interventions, pilots or any other studies including experiences or perceptions of any relevant stakeholders on automatic substitution of biologics were included without limitation by setting or geography. The quality of the included studies were evaluated by pre-determined criteria.

Results

Altogether, 27 studies fulfilled the inclusion criteria, of which 23 were surveys, and four semi-structured interviews reporting mainly stakeholders’ perceptions on automatic substitution. Most of the studies (56%, 15/27) were from Europe. Studies were conducted among prescribers (n = 12), pharmacists (n = 5), patients (n = 4), payers (n = 1), and mixed stakeholders (n = 5). The primary objective of the majority (81%, 22/27) of the studies was to investigate some other biosimilar topic than automatic substitution. The reported perceptions of substitution were mainly negative. Studies evaluating risks, safety or effectiveness, or reporting real-life experiences of biologic substitution were lacking except one intervention and two prospective risk management studies. The overall quality of the studies was low to moderate, and the results were not generalizable due to convenience sampling not representing the populations of interest, and low response rates.

Conclusions

The current research evidence on the automatic substitution of biologics is scarce and of low to moderate quality, reflecting low stakeholder knowledge and their cautious attitude towards biosimilars. The safe and efficient implementation of automatic substitution requires well-designed practices, pilot studies, and evolving legislation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00493-8.