Product-by-process claims in Indian patent law

On February 7, 2024, the Delhi High Court, led by Justices Yashwant Varma and Dharmesh Sharma, delivered a 188-page landmark verdict in the field of patent law. Overturning the restrictive approach adopted by a single-judge, the Division Bench broadened the scope of product-by-process claims, emphasising that patent protection extends to the product itself, provided it is novel and inventive, irrespective of the manufacturing process.

The Court was hearing appeals filed by Vifor International against various pharmaceutical companies including Corona Remedies and MSN Laboratories. Vifor sought to secure an interim injunction to prevent alleged infringement of its patented product, a claim previously denied by the single-judge.

The judgment provided critical clarity on the interpretation and enforcement of product-by-process claims within the framework of the Indian Patents Act. It addressed pivotal questions surrounding the scope, limitations and applicability of such claims, offering critical insights into patent law and its implications for the pharmaceutical industry.

Vifor’s patent IN’536 pertains to Ferric Carboxymaltose (FCM), a novel iron carbohydrate complex designed to address issues of toxicity, stability and ease of administration that plagued prior art. The application was filed on May 24, 2005, granted on June 25, 2008, and expired on October 20, 2023. Vifor alleged that Corona Remedies and MSN Laboratories infringed its patent related to FCM. Vifor’s claims described the FCM product primarily through the manufacturing process, making it a product-by-process claim. This approach was necessitated by the complexity of the product.

Vifor emphasised the distinctiveness of its FCM product, supported by extensive commercial and scientific data. It argued that the patent should cover all products exhibiting the characteristics described in the claims, irrespective of the manufacturing method

The pharmaceutical entities argued that product-by-process claims are inherently restrictive. Their products did not infringe the patent as they were manufactured through different processes.

Does a product-by-process claim protect the product regardless of how it is manufactured, or is its scope limited to products made through the disclosed process?

How should courts evaluate whether a competing product infringes a product-by-process claim, especially when alternative manufacturing methods are used?

Product-by-process claims refer to patents where the product is defined primarily by the process of its manufacture. These claims are significant in fields such as pharmaceuticals, where certain products are difficult to describe structurally but can be distinctly characterised by their production processes. In this case, Vifor's patent explicitly described the product as being produced through specific manufacturing steps. While the European Patent Office (EPO) and other jurisdictions recognise such claims, they remain enforceable only when the product is novel and distinct regardless of the process used. Under the Indian Patents Act, Section 48 provides the patentee the exclusive right to prevent third parties from making, using, or selling the patented product without authorisation. However, the scope of protection for product-by-process claims is inherently narrower, as it applies only to products derived specifically from the patented process.

European Patent Convention (EPC): Article 84 mandates that claims must clearly define the invention's scope, and Article 69 emphasises that the extent of protection is derived from claims. Product-by-process claims under the EPC are allowed if the product meets requirements for novelty and inventive step, independent of the process.

UK jurisprudence: Landmark cases like Catnic Components v Hill & Smith Ltd and Hospira UK Ltd v Novartis AG elucidate the principles of purposive construction, emphasising that claims must be interpreted in light of their technical context.

US Patent Law: In the US, product-by-process claims are treated similarly, with the burden on patentees to demonstrate that the accused product is indistinguishable from the claimed invention.

The Division Bench recognised product-by-process claims as a hybrid category, bridging the gap between product and process patents. It emphasised that such claims are inherently directed at novel products, with process terms serving as explanatory aids rather than limitations. Critiqued the single-judge’s restrictive interpretation, the Bench held that product-by-process claims extend beyond products obtained through the disclosed process. The Court clarified that product-by-process claims fall under Section 48(a) if the product is novel and inventive, rejecting attempts to confine them to process claims under Section 48(b).

Product-by-process claims: These claims represent a hybrid approach, combining features of product and process patents. These claims are invoked when a product cannot be fully described by its structure alone and must reference its manufacturing process to establish novelty. Global patent guidelines, including those of the Indian Patent Office (IPO), acknowledge the necessity of product-by-process claims for structurally indefinable products. The Division Bench referred decisions from the EPO, USPTO, and the UK, affirming the principle that novelty must focus on the product itself, not the manufacturing process. It held that the subject matter claims protect the product itself, as long as it is novel and inventive, regardless of the manufacturing process.

Novelty and patentability of product-by-process claims: A product-by-process claim must be founded on a novel and inventive product. The novelty of the product - not merely the process - determines its patentability. Claims relying solely on process novelty are treated as process patents and do not qualify as product patents. During patent evaluation, the process terms are disregarded to assess whether the product itself possesses novelty and inventiveness. A product cannot derive novelty merely from the adoption of a new process.

Interpretation of claims: Claims remain unchanged from the grant stage to infringement analysis, requiring a consistent application of novelty tests. Courts interpret claims objectively, considering the language, specifications and intent of the patentee. Process terms in product-by-process claims are considered auxiliary, intended to describe the novel attributes of the product rather than confine its scope.

Scope and protection: The scope of protection extends only to the novel product described in the claim and not to any product sharing similar characteristics unless derived from the specified process. There is distinction between "obtained by" and "obtainable by". The first phrase indicates a direct link between the product and the process, typically associated with process patents under Section 48(b) of the Indian Patents Act. The second phrase conveys the broader potential for obtaining the product through various processes, aligning with Section 48(a) for product claims.

Infringement analysis: The criteria for assessing patentability and infringement must remain consistent. Distinct standards for these stages would lead to contradictory interpretations. If a product is novel and inventive at the grant stage, it should retain the same protection during infringement analysis. The onus lies on the patentee to establish that the accused product corresponds to the novel attributes defined in the claim, irrespective of process differences. The Division Bench rejected the “double standard” approach, which applies different tests for patentability and infringement.

The single-judge’s distinction between “product-by-process” and “pure product claims” was erroneous, as both must align with principles of novelty and inventive step. Product-by-process claims cannot be restricted to the process terms alone. The inventive product must be assessed independently of the process, even during infringement disputes.

At its core, this judgment represents a monumental shift in how Indian patent law views product-by-process claims. The Court decisively rejected the narrow interpretation that confined these claims to products manufactured using the specific processes outlined in the patent. Instead, it embraced a globally accepted principle: patent protection for product-by-process claims extends to the product itself, provided it meets the tests of novelty and inventiveness, regardless of the process employed to create it.

This shift is particularly significant in the pharmaceutical industry, where many innovative products cannot be fully described by their structure alone and must rely on process descriptions to articulate their novel attributes. The judgment acknowledges the inherent challenges faced by inventors in patenting complex chemical and biological products, offering them broader protection while upholding the integrity of the patent system.

The Delhi High Court’s judgment is a landmark ruling that reinforces the foundational principles of Indian patent law while adapting to the complexities of modern innovation. By broadening the interpretation of product-by-process claims and prioritising the novelty of the product over the process, the Court has laid the groundwork for a more inclusive and equitable patent regime.

This decision not only resolves the specific legal dispute at hand but also serves as a beacon for the pharmaceutical and technological sectors, offering a framework that promotes innovation, ensures consistency and aligns Indian patent law with global standards. It is a pivotal moment in the evolution of Indian patent jurisprudence, reflecting a progressive and forward-thinking approach to the challenges of modern intellectual property law.

Ajay Amitabh Suman is a patent and trademark attorney.