Landmark ruling in pharma appeal cements scope of product-by-process claims

In an appeal brought by Vifor, a Delhi High Court division bench has issued a landmark judgment that clarifies the ambiguity of assessment and scope of product-by-process claims and infringement thereof.

On 7 February 2024 the bench held that patent protection awarded from product-by-process claims would extend to the product regardless of the process used for its manufacture, provided that the product itself is novel and inventive (FAO (OS)(COMM) 159-161/2023).

Accordingly, the bench allowed Vifor’s appeals and set aside the single judge’s order denying Vifor an interim injunction against MSN Laboratories, Dr Reddy’s Laboratories and Corona Remedies, which are all prominent generics manufacturers in India.

Case background

Product-by-process claims are a subspecies of product claims. They are used in cases where a novel and inventive product cannot be described by its characteristics alone and process terms are required to properly describe it. While the claimed subject matter is still novel and inventive, it is described through the means of a process that may have been used to make the product.

Vifor filed three separate suits seeking interim injunctions to prevent the defendants from infringing its patent titled “Water Soluble Iron Carbohydrate Complex and a Process for Producing Water Soluble Iron Carbohydrate Complex” (221536). This patent relates to ferric carboxymaltose (FCM), which is used for intravenous treatment of iron-deficiency anaemia.

Vifor asserted that claim 1 of the patent was a product claim for FCM, and that the process elements used to describe the end product did not restrict its rights to the process itself. In other words, claim 1 was set out in the product-by-process format.

The defendants contended that Vifor’s patent rights were limited to the specific process described in the claims; since they used different processes to produce FCM, they maintained that their actions were not infringing.

The single judge had refused to grant Vifor an interim injunction in its 24 July 2023 ruling, holding that the product-by-process claim was essentially a process claim and that the defendants’ processes did not infringe Vifor’s suit patent.

Aggrieved, Vifor challenged this decision by filing an appeal before a division bench of the Delhi High Court.

The bench’s ruling

The appellate bench provided a detailed judgment that clearly outlined the legal position on product-by-process claims.

Product-by-process claims

A product-by-process claim straddles the boundaries between product and process patents. As such a patent is founded on a claim relating to a novel product that cannot be fully described by its structure, the applicant is compelled to refer to the manufacturing process in order to describe its invention.

Product-by-process claims do not relate to products that are rendered novel merely because they have been produced by a new process; if novelty was claimed only in respect of a process, these products would be treated and granted as process patents.

Any reference to process terms in product-by-process claims only aids in explaining the novel attributes of a new product, unknown in the prior art.

Under the rule of necessity, patent registries and courts around the world acknowledge and accept the possibility of structurally undefinable products.

Patentability must be examined and evaluated independently of the allocation of an international non-proprietary name to a chemical formulation.

Dichotomy between product and process

The dichotomy between a product and a process does not operate in a vacuum: it is liable to external influence.

Dissimilar or double standards at the grant stage

Separate yardsticks of novelty cannot be applied when deciding whether to grant a patent and subsequent infringement, as the claim language is the same in both scenarios. If a patent is accepted to be novel and inventive at the grant stage, then there is no justification for disregarding its novelty and inventiveness when examining infringement claims. This would amount to propagating a double standard, which is an unjust and untenable approach.

Distinction between ‘obtainable by’ and ‘obtained by’

In its claim, Vifor used the words “obtainable by” to convey the process by which the claimed product could be manufactured or produced. However, as established, the process itself need not be the inventive element of a patent. The court clarified that use of the term ‘obtainable by’ corresponds to Section 48(a) of the Patents Act 1970, which grants a patentee the exclusive right to prevent third parties from misusing its product patent.

By contrast, claims featuring the words ‘obtained by’ indicate a direct link between the product and the process, and this expression amounts to process patent infringement under Section 48(b) of the act.

To determine whether protection extends to the product, the claim language and specification would have to be examined case by case, and a product-by-process claim would have to pertain to a novel and inventive product, as opposed to a process.

Errors in the single judge’s ruling

The bench held that, since the novelty of FCM appears to have been uncontested, the single judge fundamentally erred in understanding product-by-process claims as being limited to a product obtained through a specific process.

Key takeaways

The division bench’s decision provides much-needed clarity on the assessment of product-by-process claims and infringement of such patents – an issue that, until now, had not been decisively elucidated in Indian patent jurisprudence.

While the decision may not technically be binding for the final adjudication of any of the FCM patent infringement suits, it clearly outlines the legal position regarding product-by-process claims, which is in line with global benchmarks. Further, while Vifor was not granted an interim injunction as its FCM patent had expired in October 2023, the court – in a very encouraging move – granted Vifor the liberty to press its claim for deposit of percentage of sales made by the infringers in the respective suits.