Declaration of non-infringement patent: FMC Corporation vs. NATCO Pharmaceuticals.

Introduction

Indian patent law has witnessed a steady stream of genus–species cases across multiple High Courts. The post-Novartis tension has generally focused on a single question: does a later species patent stand disclosed, and therefore already claimed, by an earlier genus patent under Section 64(1)(a)? This line of inquiry has shaped much of the conversation around disclosure, anticipation, and the scope of protection in chemical and pharmaceutical inventions.

What makes the recent Delhi High Court decision in FMC Corporation v. Natco particularly intriguing is that it raises the inverse problem, one that, based on current research, Indian courts have not previously addressed: can a prior species patent anticipate a later genus patent under Section 64(1)(a)? In other words, instead of asking whether a genus swallows a species, the court is now asked to consider whether a species can swallow a genus. This reversal of the usual dynamic places the FMC v. Natco dispute in a novel jurisprudential space, making the case an important development. 

The dispute between FMC and Natco Pharma emerges from a long-running and complex battle over the agrochemical compound Cyantraniliprole, a blockbuster insecticide used widely in modern crop protection.

 At the centre of this specific conflict lies an intermediate chemical—2-amino-5-cyano-N,3-dimethylbenzamide, protected under Claim 12 of Indian Patent IN’645, co-owned by FMC Corporation and FMC IP Technology GmbH. Although this patent is nearing its expiry date in December 2025, the final months of exclusivity have become the setting for a fresh round of litigation, triggered by Natco’s recent launch of a Cyantraniliprole-based product. 

Background

The story begins with FMC filing a quia timet action, essentially a preventive suit, aimed at stopping Natco from manufacturing or commercialising its product “Cyantraniliprole 10.26% OD.” 

In this regard, FMC argued that production of this formulation necessarily involves the use of the patented intermediate contained in Claim 12 of IN’645, and emphasizes that Natco itself has acknowledged using the compound. From FMC’s perspective, this admission leaves little doubt: the manufacturing pathway allegedly crosses into protected territory, and injunctive relief is necessary to prevent the erosion of FMC’s patent rights before expiry.

FMC Corporation (USA) and FMC IP Technology GmbH (Switzerland) hold the patent, while FMC India and Cheminova India operate locally within the Indian agrochemical market. The history of the patent itself traces back to DuPont, from whom FMC acquired a broad portfolio of crop-protection technologies. Natco Pharma, on the other hand, is a major Indian manufacturer known for both pharmaceuticals and agricultural chemicals, including insecticides, herbicides, and fungicides. FMC accuses Natco of incorporating the protected intermediate into its newly launched product, thereby infringing Claim 12.

This case does not exist in a vacuum. It is one chapter in a much longer saga of legal confrontation between the two companies. Since 2019, FMC and Natco have clashed across multiple courts and through multiple patent families connected to Cyantraniliprole and to its related compound, Chlorantraniliprole. Natco has filed declaratory suits seeking findings of non-infringement, while FMC has repeatedly pursued infringement actions. Natco has also initiated revocation proceedings against IN’645, arguing that its claims lack novelty or were anticipated by an earlier Indian patent (IN’104). Parallel proceedings have unfolded internationally as well, including challenges in China that resulted in partial invalidation of related patents. All of this forms the backdrop to the current dispute.

Against this complex procedural and technical history, the present case distills into a straightforward confrontation: FMC maintains that Natco’s admitted use of the patented intermediate constitutes clear infringement and warrants urgent judicial intervention, while Natco counters that the patent itself is invalid or improperly extended through multiple related filings, a strategy it characterizes as an attempt at evergreening. 

Now, with the procedural context in place, we can turn to the real patent question at the heart of the case and explore why it is legally significant.

The legal issue

The legal issue at the heart of this dispute revolves around a classic problem in patent law: whether a later, broader patent claim can survive when an earlier patent has already disclosed a more specific version of the same invention.

The case involves two patents. The first, IN’104, is an older patent that claimed specific 2-aminobenzamide compounds. The second, IN’645, is a newer patent whose contested Claim 12 attempts to protect a broader family of related compounds. When the court compared the chemical structures disclosed in both patents, it found something decisive: the earlier patent already contained at least one compound that was identical to a compound included within the broader claim of the later patent. In other words, the specific molecule (the “species”) had been disclosed long before, and now appeared again inside a wider category (the “genus”).

This finding triggered a well-established principle in patent law. Across jurisdictions the rule is the same: a specific prior disclosure anticipates a later, more general claim. Courts often summarize this with the maxim: “Whatever would infringe if later, anticipates if earlier.” Allowing a genus patent after a species has already been patented would effectively extend the monopoly on that same species for another 20 years, resulting in impermissible double patenting.

Applying this principle, the court concluded that Claim 1 of IN’104 operates as the species, while Claim 12 of IN’645 functions as the genus. Because the broader claim necessarily includes the earlier-disclosed species, the novelty of the later claim cannot stand. As a result, the defendant successfully raised a credible challenge to the validity of the suit patent.

In summary, the Delhi High Court concluded that IN’104 (the earlier “species” patent) and IN’645 (the latter “genus” patent) share a common chemical core. The court pointed out that both disclosures feature the same benzene backbone, identical substituents at positions 1 and 2 (C(O)NH and NH₂), and that both sets of claim’s concern 2-aminobenzamide compounds. On that basis the court treated IN’104 as a species and IN’645 as the corresponding genus, and held, at least at the prima facie stage, that the prior species anticipates the later genus, undermining the novelty of Claim 12 of IN’645.

Conclusion

As this case shows, the legal patent landscape in India continues to evolve in unexpected and sometimes unconventional ways. The court’s approach in FMC v. Natco highlights how nuanced, and at times unsettled, the patent framework remains, especially when questions of anticipation, disclosure, and claim scope intersect. It is a reminder that Indian patent practice is both complex and fast-moving, shaped simultaneously by local jurisprudence, comparative influences, and the technical specificities of each invention.

For SMEs navigating this shifting terrain, understanding these developments is essential. And if you ever need deeper insight into the Indian patent system or guidance on cases like this one, our team is here to help. You can always reach out to the India Helpdesk, where we assist clients with these issues and a wide range of related matters.