1. Meaning 

A biosimilar is a biological medicinal product demonstrated to be highly similar to an already authorised reference biological medicine, with no clinically meaningful differences in safety, purity and potency (or efficacy, depending on the regulatory framework).

Unlike conventional generic medicines, which generally contain the same chemically defined active ingredient as the reference drug, biosimilars are produced using living cells or biological systems. Their molecular structures, manufacturing processes and biological activities are more complex.

Examples include biosimilars of insulin, erythropoietin, monoclonal antibodies and certain cancer treatments.

The biosimilar approval pathway is the statutory and scientific process through which a regulatory authority determines whether a proposed biosimilar can be marketed. It balances four major objectives:

Patient safety and therapeutic effectiveness.

Scientific comparability with the reference product.

Access to more affordable biological medicines.

Protection against misleading claims, inadequate manufacturing controls and unsupported interchangeability.

The governing rules vary by country. For an India-focused legal analysis, the principal framework includes the Drugs and Cosmetics Act, 1940, the New Drugs and Clinical Trials Rules, 2019, and India's biosimilar-specific guidelines. Other influential systems include the United States' Public Health Service Act and the European Union's pharmaceutical regulatory framework.

2. Regulatory framework in India

India regulates biosimilar development through a combination of legislation, subordinate rules, technical guidelines and regulatory review.

The Central Drugs Standard Control Organisation (CDSCO) and the relevant central and state authorities exercise regulatory functions according to their respective statutory powers. The Department of Biotechnology has also played a role in developing India's biosimilar regulatory framework.

A critical legal distinction is that a technical guideline is not necessarily equivalent to a statute or binding rule. Its legal effect depends on the enabling legislation, the applicable regulatory instrument and the context in which it is applied.

3. Step-by-step biosimilar approval pathway

Regulatory approval workflow

Identify the reference biological medicine

Select an authorised reference product that meets the requirements of the relevant jurisdiction.

Establish manufacturing and analytical comparability

Characterise molecular structure, biological activity, purity, impurities and product variability.

Conduct non-clinical and clinical assessment as required

Generate comparative pharmacokinetic, pharmacodynamic, safety, efficacy and immunogenicity evidence appropriate to the product.

Submit the regulatory dossier

Present manufacturing data, quality controls, comparability evidence, clinical data, proposed labelling and pharmacovigilance arrangements.

Regulatory scientific review

The authority assesses the total evidence, seeks clarifications where necessary and may inspect manufacturing facilities.

Marketing authorisation

Approval is granted only if the applicable statutory and scientific requirements are satisfied.

Post-approval monitoring

Monitor adverse events, immunogenicity, product quality, manufacturing changes and emerging safety signals.

This is a generalised workflow, not a substitute for jurisdiction-specific filing requirements. India's precise requirements depend on the product and applicable regulatory provisions.

CDSCO+2

Stage 1: Reference product selection

The manufacturer must identify the reference biological product against which similarity will be demonstrated.

The reference product provides the benchmark for the proposed biosimilar's quality attributes, biological activity, pharmacokinetics, safety and efficacy. The acceptability of the reference product, including its source and authorisation status, depends on the jurisdiction's rules.

Legal significance: A manufacturer cannot simply declare two biological products equivalent. The comparison must be scientifically justified and meet the regulator's reference-product requirements.

Stage 2: Analytical and quality comparability

This is the foundation of biosimilar development. The manufacturer compares the proposed product with the reference product using validated analytical and functional methods.

The assessment may include:

Primary amino-acid sequence and higher-order molecular structure.

Glycosylation and other post-translational modifications.

Biological potency and functional activity.

Purity, aggregates, impurities and degradation products.

Stability, formulation and manufacturing consistency.

Because biological products can exhibit natural variability, the question is not whether every measurement is identical. The question is whether identified differences are understood and do not undermine the conclusion of biosimilarity.

Stage 3: Non-clinical assessment

Non-clinical studies are selected according to the nature of the product and the uncertainties remaining after analytical testing. These may include functional assays, pharmacology and, where scientifically justified, toxicology studies.

A biosimilar programme is not necessarily required to repeat every study conducted for the original biological medicine. The regulatory approach is evidence-based and proportionate to the residual uncertainty.

Stage 4: Clinical assessment

Clinical evidence may include comparative studies of:

Pharmacokinetics (PK): how the body absorbs, distributes and eliminates the medicine.

Pharmacodynamics (PD): the biological effects of the medicine.

Immunogenicity: whether the medicine induces an immune response, including anti-drug antibodies.

Clinical safety and efficacy: whether any remaining uncertainty about clinically meaningful differences has been resolved.

The extent of clinical testing depends on the product and the applicable rules. Regulators may accept a scientifically justified reduced clinical package where analytical, functional and other evidence is sufficiently persuasive.

FDA+1

Stage 5: Dossier submission and review

The application generally contains a structured technical dossier covering:

Administrative and legal documentation.

Product composition and manufacturing process.

Quality specifications and analytical comparability.

Non-clinical and clinical evidence.

Proposed indications, dosage and product information.

Risk-management and pharmacovigilance plans.

In India, applicants should consult the CDSCO's official Guidelines on Similar Biologics alongside the applicable legislation and current regulatory instructions.

CDSCO+1

Stage 6: Post-marketing obligations

Approval does not end regulatory responsibility. Manufacturers and marketing-authorisation holders may need to comply with adverse-event reporting, periodic safety reporting, risk-management requirements, product-quality investigations and applicable manufacturing change controls.

Failure to comply can lead to regulatory directions, suspension or cancellation of permissions, product recalls, civil liability or criminal consequences where the relevant legal requirements are met.

4. Major legal principles governing approval

A key distinction is that marketing authorisation, patent clearance and interchangeability are separate legal questions. A product may satisfy scientific approval requirements while still being involved in patent litigation. Likewise, biosimilar approval does not automatically confer every form of substitution permission.

5. Important case laws on biosimilar approval

The following decisions are particularly relevant to regulatory approval, scientific evidence, disclosure of clinical data and patent-related disputes. Indian decisions are especially important for an India-focused analysis.

Case 1: F. Hoffmann-La Roche Ltd. v. Drugs Controller General of India (Delhi High Court, 2016)

Citation: 2016 SCC OnLine Del 2358.

Background: Roche challenged regulatory approval and marketing of biosimilar versions of trastuzumab, the biological medicine marketed as Herceptin. The litigation raised questions about compliance with India's biosimilar guidelines and the evidence supporting regulatory approval.

Legal significance: The dispute illustrates the tension between regulatory approval, the scientific evidence needed to establish biosimilarity and the innovator's attempt to prevent products from being marketed on allegedly inadequate evidence.

Principle: A regulatory approval decision and the scientific basis for claiming biosimilarity can become subjects of judicial scrutiny where the applicable legal requirements are alleged to have been breached.

Qualification: The litigation's procedural history matters. The 2016 proceedings should not be read as establishing a universal rule that all disputed biosimilar approvals are invalid. Later proceedings and orders must be considered before determining the present legal position.

Roche India+1

Case 2: Genentech Inc. v. Drugs Controller General of India (Delhi High Court, 2016)

Citation: 2016 SCC OnLine Del 2572.

Background: This dispute concerned the approval and marketing of a purported trastuzumab biosimilar and the adequacy of the regulatory testing process.

Legal issue: Whether concerns regarding testing and the approval procedure justified judicial intervention, including interim relief.

Significance: The case is frequently relevant when considering whether courts may examine the regulatory record in biosimilar disputes. The 2025 Delhi High Court judgment discussed this earlier decision while addressing requests for disclosure of regulatory documents.

Indian Kanoon

Practical lesson: A party challenging a biosimilar approval should identify the specific regulatory requirement allegedly violated and support the challenge with relevant evidence. Mere disagreement with a regulator's scientific assessment is not necessarily sufficient.

Case 3: Roche Products (India) Private Limited v. Zydus Lifesciences Limited and Others (Delhi High Court, 18 February 2025)

Proceedings: Connected commercial suits, CS(COMM) 540/2016 and CS(COMM) 1119/2016; interlocutory judgment concerning discovery and production of documents.

Indian Kanoon+1

Background: Roche and related companies sought disclosure of regulatory and technical documents in disputes concerning Hetero's bevacizumab product and Zydus's trastuzumab product. They questioned the adequacy of testing and the validity of the relevant approvals. The manufacturers disputed those allegations.

Issue: Whether documents concerning clinical trials, product testing and regulatory approval were relevant and should be disclosed during the litigation.

Legal principle: The Court applied the principles governing discovery and production under Order XI Rules 12 and 14 of the Code of Civil Procedure, 1908. Documents that could shed light on the controversy may be relevant even if they are not themselves admissible as evidence at trial.

Importance for biosimilar law:

Regulatory approval can generate disputes requiring examination of the supporting scientific record.

Clinical and regulatory documents may be material to determining whether the applicable approval process was followed.

Confidentiality and proprietary interests must be considered alongside the need for relevant evidence.

An order permitting discovery is a procedural ruling; it does not, by itself, establish that the biosimilar approval was unlawful.

This is a particularly useful case for studying the evidentiary and procedural dimensions of biosimilar regulation in India.

Case 4: Sandoz Inc. v. Amgen Inc. (United States Supreme Court, 2017)

Citation: 582 U.S. 1 (2017), commonly reported as Sandoz Inc. v. Amgen Inc., 582 U.S. ___ (2017).

Official judgment: U.S. Supreme Court opinion.

Supreme Court of the United States+1

Background: Sandoz sought FDA approval for a biosimilar to Amgen's Neupogen. The dispute concerned the Biologics Price Competition and Innovation Act (BPCIA), including disclosure of the biosimilar application and advance notice of commercial marketing.

Questions before the Court:

Could a federal injunction enforce the statutory requirement to provide the application and manufacturing information to the reference-product manufacturer?

Could the biosimilar applicant provide notice of commercial marketing before obtaining FDA approval?

Holding: The Supreme Court held that the BPCIA did not make a federal injunction available to enforce the particular application-disclosure requirement at issue. It also held that notice of commercial marketing could be given before FDA licensure.

Legal significance: Biosimilar approval is governed not only by scientific standards but also by statutory procedures addressing patent disputes and market entry.

Limitation: This decision interprets US law. Its statutory holdings do not automatically apply in India, where the relevant legislation and procedures differ.

Case 5: Amgen Inc. v. Sandoz Inc. (U.S. Court of Appeals for the Federal Circuit, 2017)

Citation: 877 F.3d 1315 (Fed. Cir. 2017).

Background: Following the Supreme Court's decision, the Federal Circuit reconsidered the consequences of non-compliance with the BPCIA's information-disclosure requirements.

Significance: The Federal Circuit concluded that federal law precluded the particular state-law remedies pursued for failure to comply with the BPCIA's disclosure provision. The litigation demonstrates the importance of statutory remedies and pre-emption in biosimilar disputes.

Justia Law+1

Principle: The consequences of failing to follow a biosimilar statutory procedure depend on the remedies the legislation permits, not simply on whether a procedural obligation exists.

6. Comparison of major regulatory systems

The FDA describes analytical studies as the foundation of biosimilar assessment, while the EMA uses a stepwise comparability approach. India's official biosimilar guidelines provide its specific framework.

FDA+2

7. Common grounds for challenging a biosimilar approval

A regulatory challenge may arise where evidence supports allegations such as:

Inadequate comparability evidence: Material differences have not been sufficiently characterised or explained.

Procedural non-compliance: A mandatory trial permission, approval, inspection or other regulatory requirement was not satisfied.

Defective clinical evidence: Studies were not appropriately designed or conducted, or their findings do not support the proposed product claims.

Manufacturing or quality defects: The production process, specifications or quality controls fail applicable requirements.

Misleading labelling or promotion: The product's claims exceed its demonstrated characteristics or authorised indications.

Failure to meet continuing obligations: Post-approval safety reporting or other mandatory conditions are not fulfilled.

The appropriate remedy depends on the legal basis and evidence. Potential outcomes include further regulatory review, directions to produce documents, corrective action, suspension or cancellation of an authorisation, or judicial relief where legally justified.

8. Critical distinction: biosimilarity, interchangeability and patents

These concepts should not be treated as synonymous.

Biosimilarity concerns the scientific relationship between the proposed product and the reference product.

Interchangeability concerns whether the product may be substituted for the reference product under the relevant regulatory and legal framework.

Patent clearance concerns whether manufacture, use or marketing infringes enforceable patent rights.

Marketing authorisation concerns whether the product satisfies the regulatory conditions for marketing.

A biosimilar approval does not itself resolve patent disputes. Similarly, the existence of a patent does not establish that a product fails the scientific test for biosimilarity.

FDA+2

9. Conclusion

The biosimilar approval pathway is a science-led regulatory process operating within a broader legal framework of licensing, patient safety, clinical evidence, manufacturing quality, intellectual property and post-marketing accountability.

In India, the central questions are whether the manufacturer has demonstrated biosimilarity in accordance with the applicable regulatory framework and whether the competent authority has acted within its statutory powers. The Roche-related litigation illustrates how courts may become involved when the adequacy of testing, validity of approvals or disclosure of regulatory records is disputed.

For a complete legal assessment, the applicable statutory provisions, the current CDSCO guidelines, the precise procedural history of relevant judgments and the evidence relating to the individual product must all be examined together.

This is a general legal and regulatory explanation, not a legal opinion on any particular product or approval.