| Literature DB >> 35755898 |
Kelley D Mayden1, John M Kelton2, Joanne C Ryan2, Ali McBride3,4.
Abstract
In oncology practices across the United States, biosimilars-highly similar versions of licensed, innovator (reference) biological medicines-are currently emerging as more affordable therapeutic options. Only after a rigorous product development program, during which a proposed biosimilar is analyzed and compared with its reference biologic to demonstrate comparable clinical efficacy, safety, and tolerability, is biosimilarity supported and licensure granted by the US Food and Drug Administration. Coincidentally, many advanced practitioners (APs) are finding themselves at the forefront of introducing monoclonal antibody (mAb) biosimilars in their oncology practice. Advanced practitioners are often tasked with building the confidence of colleagues and patients who may be unfamiliar with biosimilars, skeptical about integrating them, or have yet to consider mAb biosimilars as a viable and more sustainable cancer treatment option. With this responsibility comes a number of challenges that require APs to become knowledgeable about biosimilars and approaches to their implementation. This review aims to highlight the practical implications of streamlining the integration of biosimilar therapies in an oncology practice.Entities:
Year: 2022 PMID: 35755898 PMCID: PMC9214965 DOI: 10.6004/jadpro.2022.13.4.5
Source DB: PubMed Journal: J Adv Pract Oncol ISSN: 2150-0878
Biosimilarity Concepts and Terms
| Topic | Brief explanation | |
|---|---|---|
| What is a biosimilar? |
A biosimilar is a “highly similar” version of a single FDA-licensed biologic (i.e., an RP), notwithstanding minor differences in clinically inactive components. No clinically meaningful differences are permitted between the biosimilar and the RP in terms of safety, purity, and potency. | |
| What makes biosimilars different from generic drugs? | Biosimilars are: Produced from living organisms Relatively large complex molecular structures Molecules with minor natural structural heterogeneities Sensitive to storage and handling conditions Approved based on “high similarity” to the RP and demonstrating comparable safety, purity, and potency | Generics are: Synthesized chemically Simple small-molecule drugs Structurally well defined Relatively stable and predictable Approved based on structural identicalness and “bioequivalence” to the RP |
| What differences are permitted between approved biological products such as biosimilars? |
Minor differences, or “acceptable within-product variations,” are anticipated between each biosimilar and its RP during manufacture. Acceptable within-product lot-to-lot and batch-to-batch differences are a natural occurrence, even when RPs are manufactured. All within-product variations must be marginal, vigilantly monitored, and stringently controlled so as not to affect the biologically active parts of the molecule implicated in biological functionality (i.e., no meaningful impact on clinical efficacy, safety, and immunogenicity). | |
| How are biosimilars developed? |
Biosimilars are reverse-engineered from an original biological product for which the proprietary formulation is unavailable to the biosimilar sponsor. The goal is to minimize potential variations between the proposed biosimilar and the RP. | |
| How does the development of biosimilars proceed? | A comprehensive stepwise development program is implemented. Step 1. Molecular structure and function assessments Step 2. Nonclinical assessments (including animal studies) Step 3. Clinical pharmacology assessments (pharmacokinetic and pharmacodynamic studies in addition to the assessment of immunogenicity in an adequately sensitive population) Step 4. A comparative clinical trial(s) (biosimilar vs. the RP) to confirm efficacy, safety, and immunogenicity in a population sufficiently sensitive to the detection of any clinically meaningful product differences while simultaneously mitigating patient- or disease-related issues | |
| What is the approval process for biosimilars? |
Biosimilars are approved based on an array of scientific data referred to as the totality-of-the-evidence (outlined in Steps 1–4) as opposed to a single test. Analytical studies lay the groundwork for determining biosimilarity. Substantive evidence based on analytical similarity—with a focus on biological functionality—can provide the rationale for reducing the amount of preclinical and clinical data/studies required. FDA approval of a biosimilar signifies that there are no clinically meaningful differences associated with its efficacy and safety compared with the RP. | |
| Why are there fewer clinical studies for a biosimilar compared with a reference product? |
A biosimilar is always compared with a RP that previously underwent extensive clinical study before its approval by the FDA and has been in clinical use for many years. The foundation of the biosimilar development program is an extensive comparison to show that the biosimilar and its RP are highly similar in structure and function. After the demonstration of high similarity in structure and function, a more tailored clinical development program can be utilized to probe for any clinical meaningful differences between the products. It is not necessary to recreate the entire development program. | |
| Why is the cost of biosimilars lower? |
Abbreviation of the approval process for biosimilars occurs because of the nature of the clinical development program and the approval pathway. Multiple, large, and costly clinical trials are not necessary and so this can generate health-care cost savings. | |
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| Substitution |
The practice of a retail or hospital pharmacist dispensing one biological product for another clinically equivalent or interchangeable biological product without (automatic substitution) or with the agreement of the prescriber. Substituting a biosimilar for a RP is a matter of state pharmacy law; it varies from state to state and is not within the purview of the FDA. However, only when biosimilars meet the FDA-approved interchangeable criteria will pharmacy-level substitution without consulting with the prescriber be permitted. | |
| Switching |
A decision made by the treating provider (physician/AP) to exchange one biological product with another (i.e., a biosimilar to replace a RP) with the same therapeutic intent. Ideally, switches are done in consultation with the patient. » Reverse-switching refers to a switch back from the biosimilar to the RP. » Cross-switching refers to switching from one biosimilar to another biosimilar of the same originator biologic. | |
| Extrapolation |
When the sponsor of a proposed biosimilar elects to expand the indication(s) covered to include another one (or more) of the indications held by the RP, but for which direct tests in a comparative clinical trial(s) specific to that indication(s) were not conducted. Scientific justification must be provided in order to extrapolate an indication (e.g., pharmacokinetic bioequivalence must be established and the existing indication must have been sensitive enough to detect any clinically meaningful differences). | |
| Interchangeability |
Interchangeability is when the FDA considers that a biosimilar “ Interchangeability would allow a substitution of the RP with a biosimilar without the prescribing health-care provider intervening. A designation of interchangeable requires additional clinical switching studies | |
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| What are ADAs? |
ADAs are anti-drug antibodies; they can develop when biological drugs become recognized as non-self and a humoral immune response occurs. If a patient develops ADAs to a particular RP or biosimilar, the likelihood that they develop ADAs to other biosimilars of that RP is high. ADAs may be a medical concern if they are associated with drug inactivation, increased clearance, and subsequent loss of efficacy, and/or toxicity of a biologic. The extent of ADA formation varies among biologic class, disease state, and patient characteristics. Modern biologics are designed to minimize the formation of ADAs. | |
| What are NAbs? |
NAbs are neutralizing ADAs. If high titers of high-affinity NAbs develop, they can reduce the therapeutic activity of a biological drug by speeding up its clearance from the body, and by binding to variable regions of the antibody to prevent targeting of the biological effect. | |
Note. ADAs = anti-drug antibodies; AP = advanced practitioner; FDA = US Food and Drug Administration; NAbs = neutralizing antibodies; RP = reference product. Information from American Society of Clinical Oncology (2015); Blevins (2019); Chiu & Gilliland (2016); Christl (2018); Christl & Lim (2018); Cuellar et al. (2019); Curigliano et al. (2016); Demler (2018); FDA (2015, 2017b, 2019b, 2020b); Gabay (2017); Grampp & Ramanan (2015); Isaacs et al. (2017); Kim et al. (2020); Krishna & Nadler (2016); Lyman et al. (2018); Markus et al. (2017); Mayden et al. (2015); McClellan et al. (2019); McMahon Publishing (2013); NIH National Cancer Institute (2019); Pittman et al. (2016, 2019); Schellekens et al. (2016); Stanton (2017); Stebbing et al. (2020); Thill et al. (2019); Rumore et al. (2016); Webster et al. (2019); Welch (2017); van Brummelen et al. (2016).
Figure 1Biosimilars and their reference products must function in a clinically equivalent manner. Concept adapted from Webster et al. (2019).
Figure 2A stepwise approach is adopted to amass the science-based evidence required for the regulatory approval of biosimilars. PD = pharmacodynamic; PK = pharmacokinetic; US = United States. Information from Christl & Lim (2018); McClellan et al. (2019); Stebbing et al. (2020); Yuan et al. (2018).
Figure 3Existing and pipeline oncology monoclonal antibody biosimilars. FDA = Food and Drug Administration; mAb = monoclonal antibody; US = United States. Information from Biehn & Nell (2022)a aThis approval and development timeline is current to July 6, 2020.
Figure 4Patients in the US who were already aware of biosimilars viewed many aspects about them more positively than those who were unaware of biosimilars. An independent survey company conducted a 10- to 20-minute survey consisting of up to 56 closed-ended as well as open-ended questions. Among the 1,241 US respondents, 312 commented from an oncology perspective, comprising 188 patients diagnosed with cancer in the past 2 years, 89 patients diagnosed with cancer who had participated in patient support groups, and 35 respondents who were caregivers. The remaining 679 and 250 respondents had inflammatory disease and were from the general population, respectively. Perceptions were assessed among 610 respondents who were unaware of biosimilars and 270 respondents who were aware. US = United States. Information from Jacobs et al. (2016).
Potential Resources to Consider for Patient Use
| Organization | Details of materials | Link |
|---|---|---|
| US Food and Drug Administration (FDA) | Regularly updated patient materials about the basics of biosimilars, FAQs, and PDF infographics. |
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| Canadian Agency for Drugs and Technologies in Health (CADTH) | A concise tool about biosimilar basics for patients prescribed a biosimilar. The CADTH is an independent, not-for-profit organization. Patients can subscribe to a CADTH newsletter and follow CADTH on Twitter. |
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| American Pharmacists Association (APhA) | Biologics and biosimilar drug products: pharmacist guide to patients’ frequently asked questions. |
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| Cancer Support Community | A website with patient information, a quick patient guide, and videos about why biosimilars are important. Includes a Cancer Support Community locater. |
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| Susan G. Komen | Patient materials related to basic facts about biosimilars: includes various fact sheets, a video, and podcasts. |
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| American Cancer Society (ACS) Cancer Action Network | Public policy resources that provide patient information and videos on understanding biosimilars, and FAQs. |
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| Cancer Care Ontario (CCO) | Biosimilar information that patients need to know (more specific to Canada) with an online format, video, and PDF handout with space for patients to make notes about questions they may have. |
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| European Society for Medical Oncology (ESMO) Biosimilars Portal: Patient Resources | Predominantly EU-focused materials that address patient concerns regarding biosimilars. The materials include infographics, a video (in 8 languages), and questions and answers about biosimilars (in 23 languages). A link is also provided to US FDA patient materials. |
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| Explanation of Benefits (EOB) information | A website that patients can use to help them decipher their explanation of benefits. |
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Note. EU = European Union; FAQs = frequently asked questions.
Figure 5An example of a basic patient handout that could be used or adapted for patients starting or switching to a biosimilar.
Resources for Health-Care Providers
| Organization | Description of resources | Reference/Link |
|---|---|---|
| US Food and Drug Administration (FDA) product information | A repository of FDA-licensed biosimilar products with links to prescribing information. |
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| US FDA Biosimilar Guidances | Biosimilars guidance drafted for industry. |
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| US FDA | A premier source of regularly updated information on biosimilar topics relevant to the education of health-care professionals. Also available are healthcare-provider outreach materials such as webinars, videos, fact sheets, FDA staff presentations and articles, infographics, and a stakeholder toolkit with links to social media posts (i.e., Twitter, Facebook, and LinkedIn) among other tools, including patient materials. |
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| US FDA | All the FDA Guidance documents concerning their interpretation of policy on regulatory issues relevant to biologics, which includes biosimilars. Covered are the design, production, labeling, promotion, manufacturing, and testing of regulated products, as well as inspection and enforcement policies, among other aspects. |
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| US FDA Center for Drug Evaluation and Research | The “Purple Book” lists all available US FDA-licensed biological products showing exclusivity expiry dates and biosimilarity or interchangeability evaluations to date. |
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| National Comprehensive Cancer Network (NCCN) | A platform (with free registration) that provides the NCCN guidelines by cancer site and includes a reference to FDA-licensed biosimilars within the context of the current clinical practice guidelines in oncology for: breast cancers, cervical cancers, central nervous system cancers, rectal cancers, non-small cell lung cancers, B-cell lymphoma, kidney cancers, chronic lymphocytic leukemia/small lymphocytic lymphoma. |
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| National Conference of State Legislatures (NCSL) | State laws and legislation related to biologic medications and substitution of biosimilars (enacted state laws, state-by-state). |
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| Congress.Gov | Search this website to learn about and track US legislative bills related to biosimilars that have been introduced into Congress. A search term of “biosimilar” will yield many results that can subsequently be refined according to need. |
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| MedWatch | The FDA safety information and adverse event-reporting program. |
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| American Society of Clinical Oncology (ASCO) CancerLinQ database | A network designed to improve patient care via the transfer of a practice's electronic health record into the secure CancerLinQ platform. Large amounts of real-world data are de-identified, sorted, and harmonized to provide quality metrics in real-time, which can help inform clinicians’ care decisions. |
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| Biosimilars Council | A website with a multitude of materials, videos, blogs, news, and other resources. |
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| Biosimilars Forum | A website hosting evidence-based information to inform and support public policies pertaining to biosimilars, with links to downloadable educational resources, the latest news on biosimilars, and surveys of interest. |
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| European Medicines Agency (EMA) | European guidelines relevant to biosimilars, specific biosimilar products, and other guidelines relevant for biosimilars. |
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| The Center for Biosimilars | News, resources by specialty (including oncology), multimedia (insights, interviews, peer exchange and podcasts), upcoming conferences, approved biosimilars, etc. |
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| European Specialist Nurses Organisation (ESNO) | An EU information and communication guide for nurses addressing efficient switching from biological medicines to biosimilars. It includes FAQs and sample answers that, although they will differ by country/region/hospital, could be adapted to fit specific circumstances. |
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| Cancer Connect | Information about biosimilar medications for the treatment of cancer and topline information covering interchangeability, extrapolation, and the cost of biosimilars. |
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| Oncology Nursing Society (ONS): An oncology nursing overview of biosimilars | A nursing overview of biosimilars with an embedded article (requires ONS membership). |
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| National Institutes of Health – National Cancer Institute | News and events information (a blog) on the emergence of biosimilars for the treatment of cancer. Explanations are provided for various concepts related to biological products, extrapolation, interchangeability, and the European experience with biosimilars. |
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| American Society of Clinical Oncology (ASCO) | Lyman, GH, et al. ASCO statement: biosimilars in oncology. |
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| National Comprehensive Cancer Network (NCCN) Biosimilars Work Group discussions and Policy Summit | NCCN Biosimilars White Paper: Regulatory, Scientific, and Patient Safety Perspectives. 2011 |
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| Academy of Managed Care Pharmacy (AMCP) | Pharmacy-focused professional organization that supports the provision of “positive health-care outcomes through quality, accessible, and affordable pharmaceutical care.” A position statement and other policy and advocacy resources related to biosimilars can be accessed from the AMCP site. |
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| International Coalition of Medicines Regulatory Authorities (ICMRA) | ICMRA statement about confidence in biosimilar products (for health-care professionals). |
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| Community Oncology Alliance (COA) | Position statement. |
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| Biosimilar Medicines (EU) | A summary of EU position statements on physician-led switching for biosimilar medicines (Sept 2019). |
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| ISOPP International Society of Oncology Pharmacy Practitioners | Resources relevant to oncology pharmacists. |
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| European Society for Medical Oncology (ESMO) | The ESMO position paper on biosimilars in oncology: enhancing the provision of accurate education and information. 2017. Biosimilars: A position paper of the European Society for Medical Oncology, with particular reference to oncology prescribers. 2016. | |
Note. EU = European Union; FAQs = frequently asked questions. Information from National Conference of State Legislatures, (2019); Pittman et al. (2019).