Biosimilars and Generic Medicines: Regulatory and Pharmacovigilance Differences

Purpose and Scope

Generic medicines and biosimilars both provide routes to authorisation that rely substantially on knowledge generated for an already authorised reference medicine. That shared feature can make the two concepts appear more similar than they are. In the EU regulatory framework, however, a generic medicine and a biosimilar are distinct regulatory concepts because the nature of their active substances permits different forms of comparison and therefore different evidence strategies.

For a generic medicine, the active substance is generally a chemically defined substance for which the applicant can establish pharmaceutical equivalence and, where required, bioequivalence with the reference medicine. For a biosimilar, the active substance is biological and cannot ordinarily be demonstrated to be an exact molecular copy of the reference product. The regulatory question is consequently one of high similarity and absence of clinically meaningful differences, established through a structured comparability exercise. EMA explicitly states that a biosimilar is not regarded as a generic of a biological medicine. [1,2]

The distinction is important to pharmacovigilance because the development pathway determines the evidence context in which post-authorisation safety information is interpreted. It also affects how the product should be identified in safety reports, how evidence from the reference medicine is used and how biological characteristics such as immunogenicity and manufacturing variability are considered.

This article compares the two pathways without treating either as inherently safer or less safe. The purpose is to explain why the regulatory systems are different, how those differences arise from the underlying science, and what an experienced pharmacovigilance professional should preserve when managing safety information for either type of product.

The Common Regulatory Starting Point

Both generic and biosimilar development depend on an existing reference medicine. The applicant therefore does not begin with the same evidentiary task as the developer of a completely new active substance. Existing knowledge about the reference medicine provides an established foundation concerning quality, pharmacology, clinical use and safety.

The similarity ends at that broad principle. The nature of the comparison is determined by what can scientifically be demonstrated about the proposed product. EU legislation recognises the generic pathway in Article 10(1) of Directive 2001/83/EC and the similar biological medicinal-product pathway in Article 10(4). EMA's procedural material describes a biosimilar as a biological medicinal product similar to an authorised reference biological medicinal product and explains that the application relies on a head-to-head comparability exercise. [2,3]

The resulting distinction can be expressed as follows:

The table is a conceptual comparison rather than a complete description of either authorisation procedure. Individual applications can involve additional regulatory requirements, and hybrid medicines are a separate category that should not be conflated with either a conventional generic or a biosimilar.

Why the Scientific Difference Matters

The regulatory distinction originates in the characteristics of the medicines themselves. A conventional small-molecule active substance can generally be described by a defined chemical structure and reproduced through chemical synthesis. Once the relevant chemical identity and pharmaceutical quality have been established, the regulatory comparison can use tests appropriate to that type of substance.

Biological active substances are different because their relevant characteristics can depend on the biological source, expression system, manufacturing process and controls used to produce them. Biological products can exhibit molecular heterogeneity that is inherent to biological production and can require multiple analytical and functional methods for adequate characterisation. EMA therefore describes biosimilar development as a comprehensive, stepwise comparison with the reference medicine rather than as a conventional generic exercise. [1,4]

The important point is not simply that biological molecules are larger. Some biological active substances are relatively small proteins, while some chemically synthesised medicines are structurally complex. The decisive issue is the scientific ability to characterise and reproduce the relevant properties of the active substance and finished product using an appropriate regulatory framework.

This difference explains why the two pathways ask related but non-identical questions. The generic pathway asks whether the proposed product meets the legal and scientific conditions for a generic of the reference medicine. The biosimilar pathway asks whether the proposed biological product is highly similar to the reference product and whether there are no clinically meaningful differences within the scope of the evidence.

Pharmaceutical Equivalence and Bioequivalence in Generic Development

The generic pathway relies on the established identity of the active substance and on evidence that the proposed product has the required pharmaceutical characteristics and, where applicable, comparable systemic exposure to the reference medicine. EMA explains that generic applicants usually need to provide quality information and demonstrate that the generic produces the same levels of the active substance in the body as the reference medicine, because substantial safety and efficacy information already exists for the reference product. [5]

Bioequivalence is therefore not simply a general statement that two medicines "work the same way". It is a defined pharmacokinetic concept used within the regulatory framework to establish that exposure to the active substance is sufficiently comparable for the relevant regulatory purpose. The precise study requirements depend on the product and applicable guidance, and some products may not require a conventional in-vivo bioequivalence study.

The regulatory logic is consequently economical: once the active substance and pharmaceutical product can be appropriately characterised, the applicant does not ordinarily need to repeat the entire clinical development programme of the reference medicine. The evidence needed is directed toward demonstrating the conditions under which the reference-product knowledge can be relied upon for the proposed product.

Biosimilarity and Comparative Characterisation

The biosimilar pathway uses a different evidentiary logic. The applicant performs a head-to-head comparison with the reference biological medicine, beginning with extensive quality and analytical characterisation and proceeding to functional, non-clinical and clinical evidence as required by the scientific questions remaining at each stage.

EMA describes this as a stepwise and product-specific approach. The results of earlier comparability studies help determine the extent and type of later studies needed. The objective is therefore not to accumulate a fixed set of studies simply because the product is biological. It is to identify and resolve residual uncertainty using the most sensitive evidence available for the particular product. [2]

This approach also explains why a biosimilar development programme should not be described as a smaller version of an originator development programme. The reference product contributes substantial prior knowledge, while the biosimilar programme is designed primarily to establish similarity and address remaining uncertainty.

The Meaning of "Same" and "Similar"

The words "same" and "similar" have different regulatory significance in this context. A generic medicine is defined in relation to the same active substance as the reference medicine, subject to the legal conditions of the generic pathway. A biosimilar instead involves a biological active substance that is similar to that of the reference medicine, with the overall comparability exercise supporting the regulatory conclusion of biosimilarity. [3]

This does not mean that a biosimilar is clinically inferior, less predictable or intrinsically less safe. It means that the regulatory evidence supporting authorisation is constructed differently because exact molecular replication and the same type of direct equivalence demonstration are not generally available for biological products.

The distinction should also not be reversed into the claim that generic medicines require no scientific comparison. Generic medicines remain subject to pharmaceutical quality requirements and the applicable requirements for demonstrating equivalence. The difference is the type of equivalence that can be established and the evidence needed to establish it.

Development Evidence and the Role of the Reference Medicine

The different scientific questions lead directly to different development evidence. In generic development, the reference medicine supplies the established evidence for the active substance, while the applicant demonstrates that the proposed product meets the relevant quality and equivalence conditions. The resulting evidence package can therefore be substantially smaller than that required to establish the safety and efficacy of a new active substance.

In biosimilar development, the reference medicine serves both as a source of prior knowledge and as the comparator for a structured similarity assessment. Analytical and functional comparison is central because differences that might be invisible in a conventional pharmaceutical-equivalence framework can be relevant to a biological product. If a potentially relevant difference remains after the earlier stages, additional evidence may be needed to determine its clinical significance. [1,2]

The two approaches therefore use reference-product knowledge differently. For a generic, the established properties of the active substance and reference product support reliance on the existing clinical evidence once the generic requirements have been met. For a biosimilar, reference-product knowledge is integrated with comparative evidence throughout the assessment.

This distinction becomes particularly important when interpreting post-authorisation evidence. The reference medicine is not merely a historical comparator. It is part of the scientific context for a biosimilar, while the actual exposure remains attributable to the individual authorised product.

Immunogenicity: A Biological-Specific Consideration

Immunogenicity illustrates one of the clearest differences in pharmacovigilance reasoning. Small-molecule generic medicines can have clinically important immune-mediated adverse reactions, but the active substance is not generally assessed through the same biological-product immunogenicity framework used for therapeutic proteins and other biological medicines.

For biological products, immune responses against the active substance or product-related components can potentially affect exposure, pharmacodynamic activity, efficacy or tolerability. Their significance depends on the individual product, the characteristics of the immune response and its relationship to clinical outcomes. Consequently, immunogenicity is considered during biosimilar development and remains relevant after authorisation. [1,6]

This does not mean that every antibody response is a safety event. Nor does it mean that a biosimilar is expected to generate a greater immune response than its reference product. The relevant question is whether the evidence identifies a meaningful difference or a clinically important immune-mediated outcome.

For pharmacovigilance, this creates a practical requirement to preserve sufficient clinical and product context to connect an immunogenicity finding with the exposure and outcome being assessed.

Product Identity and Traceability

The distinction between generic and biosimilar medicines also affects the importance of product-level identification. All medicinal products need reliable identification for effective pharmacovigilance, but biological products can present additional challenges when several products have related active substances, similar names or the same international non-proprietary name.

EMA's GVP guidance for biological medicinal products emphasises the importance of product and batch traceability and the ability to distinguish biological products with the same international non-proprietary name. [7] This is not a reason to treat generic pharmacovigilance as unconcerned with product identity. Rather, the biological-product context can make loss of product identity particularly consequential when assessing product-specific safety or manufacturing questions.

For either product type, the case should preserve the medicinal product actually administered. For a biosimilar, this means that a case should not be reassigned to the reference product merely because the event is already known for the reference medicine. For a generic, it likewise means that a case should remain associated with the actual product when product-specific quality, formulation or other considerations are relevant.

The difference is therefore one of degree and context, not a binary distinction between "traceable" and "not traceable" medicines.

Batch Information and Manufacturing Questions

Batch information can be relevant to pharmacovigilance for both generic and biological medicines. A cluster of reports associated with one batch may raise a question about manufacturing, storage, distribution or another common exposure circumstance.

For biological products, manufacturing characteristics can be particularly important because the product's relevant properties may depend on the manufacturing process. A temporal association between a safety pattern and a manufacturing change therefore may warrant investigation, although the association alone does not establish causality.

The same principle applies to generics: a suspected quality defect, contamination, formulation problem or other manufacturing issue may become a safety concern. Pharmacovigilance and quality systems should therefore have appropriate interfaces regardless of product type.

What differs is the scientific interpretation of manufacturing-related variation. For a biological medicine, process-related changes can affect a range of molecular and functional attributes that require sophisticated comparability assessment. For a chemically synthesised generic, the relevant quality questions are generally framed around the defined chemical substance, pharmaceutical form and applicable quality specifications.

Pharmacokinetics and Exposure

Pharmacokinetic evidence illustrates another important difference. For many small-molecule generics, bioequivalence focuses on demonstrating sufficiently comparable exposure to the active substance, commonly using measures such as systemic exposure and peak concentration where appropriate.

For biological products, pharmacokinetic comparison can involve more complex considerations because distribution, clearance and other disposition processes may be affected by the biological characteristics of the product. EMA notes that biosimilar PK assessment may need to consider distribution and elimination as well as absorption. [8]

The distinction is not that pharmacokinetics is relevant only to generics or only to biosimilars. Rather, the properties of the active substance determine which pharmacokinetic questions are scientifically informative and how those results contribute to the overall regulatory conclusion.

Clinical Evidence: Equivalence Versus Residual Uncertainty

The clinical evidence used for a generic and a biosimilar should not be interpreted as though the two programmes were simply different-sized versions of the same trial strategy.

For a generic, once the appropriate pharmaceutical and bioequivalence conditions are established, repeating efficacy trials for the reference medicine would generally add little value because the active substance is already established and the regulatory pathway is designed to rely on that knowledge.

For a biosimilar, comparative clinical evidence may be used when analytical and functional evidence cannot fully resolve a relevant question. The amount and nature of clinical evidence are product-specific and depend on the residual uncertainty after the preceding stages of comparison. EMA's biosimilar framework expressly describes this stepwise logic. [2]

This is why the phrase "more clinical trials" can be misleading when comparing biosimilars and generics. The relevant difference is not simply quantity. It is the scientific role of the evidence within each regulatory pathway.

Extrapolation and Reference-Product Knowledge

Biosimilar authorisation can involve extrapolation to indications of the reference product when the scientific and regulatory criteria are satisfied. The rationale depends on the totality of evidence, including the mechanism of action and the ability of the available evidence to support the proposed indications. [1]

A conventional generic also relies heavily on the reference medicine's established indications and clinical knowledge, subject to the legal conditions of its particular application. The underlying logic differs because the generic pathway is based on the established identity of the active substance and the demonstration of equivalence required by that pathway.

For pharmacovigilance, the practical lesson is that indication should remain part of the clinical context. Experience with a medicine in different populations does not necessarily represent one homogeneous evidence set, particularly where disease characteristics, concomitant therapies or treatment duration differ.

Interchangeability Is Not the Same Regulatory Concept as Equivalence

The terms equivalence, biosimilarity and interchangeability should not be used interchangeably. They describe different regulatory or scientific concepts.

For generic medicines, the authorisation pathway establishes the conditions under which the generic can be authorised as a product corresponding to the reference medicine within the applicable legal framework. For biosimilars, the EU framework establishes biosimilarity through comparative evidence, and EMA and the Heads of Medicines Agencies have separately stated that EU-authorised biosimilars are scientifically interchangeable with their reference medicines and with equivalent biosimilars. [9]

At the same time, Member States remain responsible for decisions concerning prescribing and whether automatic substitution at pharmacy level is permitted. [1,9] These national policy decisions should not be confused with the scientific conclusion of biosimilarity or with the pharmacovigilance requirement to preserve exposure history.

Switching and Pharmacovigilance

Switching between products can occur with both generic and biological medicines, but the pharmacovigilance interpretation of switching can be particularly important for biological products where immune-mediated or delayed events are under consideration.

When a patient changes from one biological product to another, the safety record should preserve the sequence and timing of exposures. An event occurring after the switch should not automatically be attributed to the new product; previous exposure may remain relevant to the clinical question.

The same general principle applies to generic substitution: the product actually administered should be identifiable when relevant to the safety assessment. However, the biological context can create additional scientific questions concerning immunogenicity, cumulative exposure and product-specific characteristics.

Signal Detection: What Changes and What Does Not

Signal management remains governed by the general pharmacovigilance framework for both generics and biosimilars. The basic task is to identify and evaluate information suggesting a possible new or changed safety concern.

What changes is the evidence context. For a generic, the assessor may focus on the known profile of the active substance, product-specific exposure, formulation or quality information and relevant comparative evidence. For a biosimilar, the assessor may additionally need to consider the reference product, immunogenicity, manufacturing characteristics, switching and evidence from related biological products.

Neither approach should rely on automatic pooling. For a biosimilar, combining reference and biosimilar cases under a shared active-substance identifier can erase information needed to detect a product-specific pattern. Conversely, analysing a biosimilar in complete isolation can discard relevant reference-product knowledge.

The appropriate analytical level should therefore be determined by the safety question.

Using Reference-Product Safety Information

Reference-product knowledge is important in both pathways, but its role differs. Generic development relies heavily on the established safety and efficacy knowledge of the reference medicine because the active substance is the same within the meaning of the generic legal framework.

For a biosimilar, reference-product information provides biological and clinical context while the biosimilar remains a distinct product. A known adverse reaction of the reference product may therefore help establish biological plausibility or expectedness, but it does not convert a biosimilar case into a reference-product case.

The distinction can be expressed simply:

Reference-product evidence may inform the assessment; it does not change the identity of the exposure.

This principle is particularly important when a potential signal is first detected with a biosimilar. The assessor should ask whether the observation is already known for the reference product, whether it is consistent with the shared mechanism, whether there are product-specific features and whether the evidence supports a broader conclusion.

Risk Management and Aggregate Evaluation

Both generic and biosimilar medicines are subject to the general EU pharmacovigilance framework, including aggregate safety evaluation and risk management requirements applicable to the product. A biosimilar does not operate under a separate pharmacovigilance system merely because its development involved a comparability exercise.

For a biosimilar, the reference-product risk profile can provide an important starting point for the safety specification and ongoing assessment. However, product-specific evidence may alter the understanding of a risk, and information affecting related products may need to be considered systematically.

For generics, the established active-substance safety profile likewise provides the principal context, while product-specific information can become important where the concern relates to formulation, excipients, manufacturing, quality or another product-specific characteristic.

In both cases, aggregate evaluation should integrate the available evidence rather than simply reproduce the reference medicine's safety profile.

Product-Specific Safety and Quality Questions

A generic or biosimilar can generate safety information that is not explained adequately by the reference medicine's established profile. The possibility should be approached as a scientific question rather than as evidence that the follow-on product is intrinsically different in clinical safety.

For a generic, potentially product-specific issues may include formulation, excipients, manufacturing defects, contamination, dose delivery or other quality characteristics. For a biosimilar, similar questions can arise, together with questions concerning biological attributes, immunogenicity, manufacturing changes and product-specific molecular characteristics.

In either case, the pharmacovigilance assessment should distinguish an intrinsic medicinal-product risk from harm caused by administration, handling, storage, medication error or another external factor. The distinction matters because the appropriate regulatory and risk-minimisation response depends on the mechanism of the problem.

Quality and Pharmacovigilance Interfaces

The relationship between pharmacovigilance and quality is relevant to both product types. A safety report may contain information suggesting a possible quality defect, while a quality complaint may contain information relevant to patient safety.

The systems should therefore provide controlled routes for exchanging safety-relevant information. Pharmacovigilance should not independently determine that a manufacturing defect caused a clinical event, and quality should not be expected to resolve a clinical safety question without the appropriate medical and pharmacovigilance assessment.

The interface becomes especially important for biological medicines because manufacturing changes and process characteristics can be closely connected to product attributes. This does not make every post-change event a manufacturing-related event. It makes the manufacturing context a potentially relevant part of the investigation.

Data Quality and Coding

The differences between generics and biosimilars make consistent product coding important. A safety database may contain active-substance identifiers, invented names, manufacturer information, formulation details, batch numbers and other product attributes. The data model should allow the organisation to preserve the information needed for the relevant safety questions.

For biosimilars, collapsing several products into one active-substance category can be particularly problematic if it prevents later reconstruction of the product actually administered. For generics, inappropriate aggregation can likewise obscure product-specific quality or formulation issues.

Data-quality controls should therefore address both consistency and preservation of granularity. Standardisation should make information comparable without destroying distinctions that may become important later.

Practical Comparison for Pharmacovigilance

The following comparison summarises the principal consequences for safety surveillance:

The table should not be interpreted as creating separate pharmacovigilance standards. Both products remain within the general EU pharmacovigilance system.

Common Conceptual Errors

Several recurring errors arise when the two categories are compared too simplistically.

Calling a biosimilar a biological generic. This obscures the distinct legal and scientific basis of the biosimilar pathway. EMA explicitly distinguishes biosimilars from generic medicines. [1]

Assuming a generic requires no comparative evidence. Generic development still requires pharmaceutical quality evidence and the applicable demonstration of equivalence; it simply uses a different type of evidence from the biosimilar pathway.

Assuming biosimilar means clinically less certain. Biosimilarity is a regulatory conclusion based on a structured evidence package. The existence of residual scientific questions during development does not mean that an authorised biosimilar has an unresolved general safety or efficacy deficiency.

Treating biosimilarity as identity. A biosimilar remains a distinct medicinal product and should remain identifiable in pharmacovigilance.

Treating interchangeability as loss of traceability. Scientific interchangeability does not remove the value of knowing which product was administered.

Assuming every biological safety issue is a class effect. Evidence from a related product can provide context, but a class conclusion requires appropriate scientific assessment.

Assuming every post-manufacturing-change event is caused by the change. Temporal association can justify investigation but does not establish causality.

These are conceptual failure modes rather than claims about documented inspection findings.

Inspection Perspective

An inspection of a pharmacovigilance system covering both generic and biosimilar medicines could reasonably examine whether the organisation understands the evidentiary context of each product and whether that understanding is reflected in operational controls.

For generic products, an inspector could examine whether product-specific safety information can be distinguished where relevant, whether quality complaints are appropriately interfaced with pharmacovigilance, and whether aggregate assessments appropriately use the established reference-product safety profile without overlooking new product-specific information.

For biosimilars, additional questions could concern whether the actual biosimilar exposure can be distinguished from the reference product and other related products, whether switching history is retained, whether immunogenicity information is interpreted in clinical context, and whether relevant manufacturing or quality information can be connected to safety assessment.

These are illustrative inspection questions. They are not presented as documented inspection findings.

The strongest evidence of an effective system is reconstructability. A reviewer should be able to follow a significant safety issue from the original exposure through product identification, case assessment, comparative evidence, signal evaluation, decision-making and follow-up. The precise evidence required will depend on the safety question.

Practical Review Framework

When a safety issue involves a generic or biosimilar, an assessor can use a common framework while adapting the scientific questions to the product type:

Identify the actual medicinal product
              ↓
Establish the relevant exposure history
              ↓
Characterise the clinical event
              ↓
Consider reference-product knowledge
              ↓
Identify product-specific characteristics
              ↓
Consider quality / manufacturing information
              ↓
Consider immunogenicity where relevant
              ↓
Assess alternative explanations
              ↓
Review comparative and external evidence
              ↓
Determine whether the concern is product-specific or broader
              ↓
Assess signal / aggregate / RMP implications
              ↓
Document conclusion, uncertainty and follow-up

The framework is deliberately common to both categories. What changes is the scientific content of the questions within each step. For a generic, the assessor may focus more heavily on pharmaceutical formulation, bioequivalence context and product-quality questions. For a biosimilar, the assessment may additionally require consideration of immunogenicity, switching, biological characteristics, manufacturing changes and evidence from the reference product.

Roles and Governance

The organisation should ensure that pharmacovigilance personnel understand enough about the regulatory status and scientific characteristics of the products they assess to recognise when a generic or biosimilar issue requires specialist input.

Medical and clinical functions may contribute clinical interpretation. Regulatory functions may provide information concerning variations, commitments and regulatory assessments. Quality and manufacturing functions may hold batch, process and complaint information. Pharmacovigilance integrates relevant information into case assessment, signal management, aggregate evaluation and risk management.

The QPPV's governance role does not require the QPPV to perform every scientific assessment personally. It requires oversight of whether the pharmacovigilance system can identify, assess, communicate and manage safety information effectively, including where product-specific evidence must be integrated with information held elsewhere in the organisation.

Key Takeaways

Generic medicines and biosimilars share the principle of building on an authorised reference medicine, but they do not use the same scientific or legal pathway.

A generic medicine is based on the established identity of the active substance and the requirements of the generic pathway, including pharmaceutical quality and the applicable demonstration of equivalence. A biosimilar is a biological medicinal product for which high similarity to a reference biological medicine is established through a structured comparability exercise.

The difference is rooted in the characteristics of the active substances and in what can be demonstrated scientifically. It is not a ranking of safety between the two categories.

For pharmacovigilance, both products remain subject to the general EU system. The biosimilar context adds particular importance to product identification, traceability, immunogenicity, switching, reference-product evidence and the relationship between manufacturing information and safety assessment.

The central operational principle is the same across both categories: use the reference medicine to inform interpretation without losing the identity and evidence of the product actually administered.

Actionable Checklist

Relationship With the Biological-Product Series

The preceding article on biosimilars established the biosimilar as a biological medicinal product with a distinct relationship to its reference medicine. This article adds the necessary comparison with generic medicines so that the reader does not interpret the biosimilar pathway through the conceptual framework used for small-molecule generics.

The next articles can therefore move from this regulatory distinction into the specific pharmacovigilance consequences. The most useful deeper subjects are product and batch traceability, switching and interchangeability, and immunogenicity. Each can then be examined in detail without repeatedly rebuilding the generic-versus-biosimilar foundation.

References

1. European Medicines Agency. Biosimilar medicines: Overview. EMA. Definition of biosimilars, distinction from generic medicines, development principles and post-authorisation pharmacovigilance.
2. European Medicines Agency. Biosimilar medicines: Marketing authorisation. EMA procedural guidance on eligibility, the comparability exercise and the case-by-case nature of biosimilar assessment.
3. European Parliament and Council. Directive 2001/83/EC on the Community code relating to medicinal products for human use, as amended. In particular Articles 10(1), 10(3) and 10(4).
4. European Medicines Agency. Guideline on similar biological medicinal products (Rev. 1). CHMP/437/04 Rev.1. Current effective overarching EU biosimilar guideline.
5. European Medicines Agency. Generic and hybrid medicines. EMA overview of generic development, reference medicines, quality requirements and bioequivalence.
6. European Medicines Agency. Guideline on immunogenicity assessment of biotechnology-derived therapeutic proteins. EMA/CHMP/BMWP/14327/2006 Rev. 1.
7. European Medicines Agency. Good pharmacovigilance practices (GVP), Product- or Population-Specific Considerations II: Biological medicinal products. EMA/168402/2014.
8. European Medicines Agency. Clinical pharmacology and pharmacokinetics: questions and answers, section on biosimilars and pharmacokinetic considerations.
9. European Medicines Agency and Heads of Medicines Agencies. Statement on the scientific rationale supporting interchangeability of biosimilar medicines in the EU. EMA/627319/2022, with associated Q&A.
10. European Commission / European Medicines Agency. EU regulatory framework and guidance for generic, hybrid and biosimilar medicinal products.

Regulatory Note

This article distinguishes legal requirements, scientific guidance and operational practice. Directive 2001/83/EC establishes the legal categories and conditions for generic and similar biological medicinal products. EMA guidelines and procedural guidance explain how the scientific and regulatory framework is applied; they are not themselves legislation.

The current effective overarching EMA biosimilar guideline remains Rev. 1 (CHMP/437/04 Rev.1), with a legal effective date of 30 April 2015. EMA opened a consultation on a proposed replacement guideline on 22 July 2026, with consultation closing on 31 October 2026. The proposed revision is not itself the current applicable guideline. [4]

The practical controls described in this article, including preservation of product identity, switching history and traceability, are presented as pharmacovigilance practice informed by the regulatory framework. They should not be interpreted as additional legal requirements unless the applicable legislation, guidance or product-specific regulatory documentation establishes such a requirement.

Regulatory requirements and scientific guidance can change. Current EU legislation, applicable EMA GVP guidance, current generic and biosimilar guidelines, product-specific regulatory documentation and relevant national requirements should therefore be checked when applying this framework to a particular product or regulatory decision.