On the Delhi High Court’s recent order in Frimline v. Smatco, Anushka Kanabar explains how the order is another step in the judicial shift towards a broad interpretation of claim construction, which is aligned with the US’ approach. Anushka is a fourth-year B.A., LL.B. (Hons.) student at the National Law School of India University. Her previous posts can be accessed here.
Frimline and the Future of Open-Ended Transition Phrases in Indian Patent Law
By Anushka Kanabar
In its recent decision in Frimline Pvt. Ltd. v. K-Smatco Lifesciences, the Delhi High Court granted an interim injunction against the infringement of a patent over a pharmaceutical composition for treating anemia. Frimline claimed that K-Smatco’s rival product, Ferrotok Plus, contained the patented component, defined in the specification as “a pharmaceutical composition comprising a combination of (a) lactoferrin, (b) one or more Guanosine Nucleotide …” This case turned on a question of claim construction: whether K-Smatco’s product, containing the element Disodium Guanosine 5-Monophosphate, could fall within the scope of the patent’s specification and thus infringing it?
This judgement has interesting implications for Indian patent law for its acceptance of Frimline’s argument that the use of the open-ended term “comprising” in the patent specification covers any product containing the claimed components, even with added features. The Court drew on its previous judgement in Guala Closures v. Agi Greenpac (2024), which relied on its previous decision in F. Hoffman-Laroche v. Cipla (2012), as well as the UK Court of Appeal in Virgin Atlantic Airways v. Premium Aircraft Interiors (2009). Interestingly, the latter had some statutory guidance in its approach, in the form of Rule 43 of the Implementing Regulations to the European Patent Convention, which states that claims should contain a characterising portion, beginning with the expression “characterised in that” or “characterised by” and specifying the technical features sought to be protected.
The interpretative technique in Frimline can be found in a range of Delhi High Court judgements following F. Hoffman-Laroche v. Cipla (2012), which states that ‘comprising’ entails that “if the claim contains three elements ‘A’, ‘B’ and ‘C’ it would still be an infringement for someone to add a fourth element ‘D.’” There is also a body of cases following Guala Closures, including, for instance, Jay Switches v. Sandhar Technologies (2024), wherein the Court interpreted minor structural differences in a fuel-cap as falling within the core specification. Frimline is therefore only another in a line of cases demonstrating a judicial shift in favour of broad claim construction.
The reasoning in Guala Closures and F. Hoffman-Laroche is analogous to American patent jurisprudence on the phrase “characterized by” and other open-ended “transition phrases.” While neither cite the American judge-made law – instances of which can be found here and here – on how transition phrases like “comprising,” “consisting of,” etc. must be interpreted as inclusive, Guala Closures notes the US Supreme Court’s approach to the interpretation of specifications as outlined in Herbert Markman v. Westview (1996), i.e., to first outline the scope of the specification, and discusses “transition phrases” in that context. Within American jurisprudence as well as under the European Patent Convention, these phrases serve the dual function of demarcating the inventive contribution from the prior art outlined in the disclosure, and more importantly, defining the essential ingredients of a claim while permitting the inclusion of extra, unwritten components.
Before this approach is examined, a small point may be made about how it may not strictly have been necessary in the facts of Frimline itself. The infringing element, Disodium Guanosine 5-Monophosphate, was explicitly included in the examples given in the patent specification and could very reasonably be argued as being taught by the specification. The Court then did have the option to allow Frimline’s argument on the basis that it ordinarily is under Section 10 of the Patents Act: that the claims literally fall within the terms of the specification. However, as we will see, the Court ends up taking a broader, more first principles approach to the issue.
Comprising A+B+C… and D?
The effect of open-ended transition phrases on claim construction, according to this line of judgements, is to permit infringement actions in respect of characteristics that may be included in the specification even when they are not. This evidently dilutes the symmetry of claims and disclosures under the Patents Act: a patentee that disclosed ingredients A and B may be able to claim A, B, C, D and more without formally seeking additions to the original patent specification.
This prevents defendants from exploiting trivial differences in products to escape liability for infringement. This results in a patent protection that is effective and comprehensive. However, the effectivity of patent protection must be balanced against social concerns, i.e., that a broad reading of “comprising” may preclude innovation that designs around existing patents. This is particularly an issue with pharmaceutical products like the one that formed the subject-matter of Frimline, because of the pervasiveness of incremental innovations in the pharmaceutical industry, in which manufacturers often add small elements to reduce side effects. The sweeping logic in Frimline risks reading follow-on ingredients as a part of the overarching patent.
So while Frimline takes a step forward in terms of doctrinal harmonization – moving Indian law closer to the US standard – this might result in tensions with existing Indian patent jurisprudence. Here I mostly refer to how Section 10 of the Patents Act – prescribing the contents of patent specifications – requires a full and particular disclosure, and the Supreme Court’s famous warnings against overbroad claims in Novartis, including its remarks against a “vast gap between the coverage and the disclosure under the patent.”
Striking a balance
The approach of the European Patent Office is insightful in this regard, because it incorporates further substantive requirements for interpreting an element following “comprising” as a part of the overall specification. Some of these include asking whether the added feature counteracts the technical purpose of the overall claim, and the threshold of “exceptional cases” wherein an addition supporting the main claim can be added as long as it corresponds to the description and subject-matter of the claimed invention. This balances the largely textual basis of claim construction (that correctly recognizes the inclusivity of “comprising”) with the need to align its scope with disclosures.
Frimline therefore reflects one aspect of the Indian courts’ approach to claim construction, one that respects and effectuates patent drafting formulae like “comprising” and “characterized by.” This is yet to be expressly balanced and harmonized with the other aspect, that stresses the need for claims to not go beyond what is disclosed in the specification. A substantive threshold for permitting such inclusions – one that balances patentees’ interests in protection against minute tweaks against the public interest in permitting incremental innovation – is in order.