Comprehensive Guide to Grounds for Patent Revocation in India

A granted patent is not always an unassailable fortress. Under Indian patent law, any patent – regardless of when it was granted – can be challenged and declared void if it fails to meet the legal standards that justify its existence. This isn’t just a theoretical possibility; patent revocation is an active, frequently used legal tool in India, both as a standalone action and as a defence in infringement suits. Section 64 of the Patents Act, 1970 is the central provision that governs this process, listing comprehensive grounds on which a patent can be revoked. Understanding these grounds is essential – whether you’re a patent holder trying to protect your rights, a competitor challenging a questionable patent, or a law student navigating patent litigation.

What is patent revocation? 🔗

Patent revocation is the legal process by which a granted patent is declared invalid and effectively cancelled. Once revoked, the patent ceases to exist, and the invention enters the public domain. Under the Patents Act, 1970, the validity of a patent can be challenged through several routes: a post-grant opposition under Section 25(2) within one year of the grant’s publication, a revocation petition under Section 64, a counterclaim filed by a defendant in an infringement suit before the High Court, revocation for non-working under Section 85, and revocation in public interest by the Central Government under Section 66.

What makes revocation especially significant in litigation is its dual-purpose nature. The same grounds listed under Section 64 that can be used to revoke a patent outright can also be pleaded as a defence by a defendant in an infringement suit. This means that when a patentee sues someone for infringement, the accused can turn around and challenge the very validity of the patent being enforced against them. It is a powerful tool that fundamentally shifts the battlefield in patent disputes.

Who can file for revocation? 🔗

Under Section 64 of the Patents Act, a revocation petition can be filed by any “person interested” or by the Central Government. Indian courts have interpreted “person interested” broadly to include any individual or entity whose commercial or research interests are materially affected by the patent’s continued existence. A counterclaim for revocation can also be raised before the High Court during an infringement suit – and importantly, under Section 104, once such a counterclaim is filed in an infringement suit before a lower court, the entire matter is transferred to the High Court for adjudication.

Grounds for revocation under Section 64 🔗

Section 64 provides a detailed, though not exhaustive, list of grounds for revocation. Each ground targets a different vulnerability in a patent’s legal standing. Here is a structured breakdown of the most critical ones.

Prior claiming (anticipation by an earlier patent) 🔗

A patent can be revoked if the invention claimed in its complete specification was already claimed in an earlier valid patent granted in India with an earlier priority date. This is the “prior claiming” ground. The logic is straightforward – if someone already holds a valid patent for the same invention with an older claim date, granting another patent for the same subject matter creates a duplicate monopoly, which the law does not permit. The earlier patent’s claim must be valid; a prior but already revoked patent cannot serve as the basis for this ground.

Entitlement issues: patent granted to the wrong person 🔗

Under Section 64(1)(b), a patent is liable to be revoked if it was granted to a person not entitled to apply for it under the Act. The Patents Act specifies who may apply for a patent – primarily the true and first inventor or their assignee. If a patent is granted to someone who is not the actual inventor and had no legitimate right to the invention, the grant itself is flawed from inception. This ground is closely linked to the concept of inventorship, which is a matter of legal entitlement, not just scientific contribution.

Wrongful obtaining of the patent 🔗

Distinct from the entitlement ground, Section 64(1)(c) deals with situations where a patent was obtained wrongfully in contravention of the rights of the petitioner or any person through whom the petitioner claims. This typically applies where the patent applicant derived the invention from the actual inventor – essentially, where the invention was “stolen” or appropriated. In such cases, the person who was rightfully entitled to the patent can petition for revocation, and may simultaneously seek to have the patent transferred to themselves.

Subject matter not an invention 🔗

If the subject matter claimed in the patent does not qualify as an “invention” within the meaning of the Patents Act, the patent can be revoked. Section 3 of the Act lists categories of subject matter that are not patentable in India – these include frivolous inventions, mere discoveries of scientific principles, mental acts, mathematical methods, and literary or artistic works. Section 3(d), in particular, has had enormous impact in pharmaceutical patent disputes. It bars patents for new forms of known substances unless they demonstrate significantly enhanced efficacy – a provision that was at the heart of the landmark Novartis AG v. Union of India (2013) case, where the Supreme Court refused a patent for a modified form of an existing cancer drug on precisely this ground.

Lack of novelty (anticipation) 🔗

One of the most commonly invoked grounds, lack of novelty arises when the invention was already publicly known or publicly used in India before the priority date of the patent claim, or was published anywhere in the world before that date. Novelty is a foundational requirement for patentability – an invention that already exists in the public domain cannot be monopolised through a patent. The relevant prior art can include published documents, prior patents, prior use in trade, or even oral knowledge within a local or indigenous community. This last point is particularly significant in India: Section 64(1)(q) specifically allows revocation if the invention was anticipated by knowledge – oral or otherwise – available within any local or indigenous community in India or elsewhere. This provision was introduced to protect traditional knowledge from being patented by third parties.

Obviousness (lack of inventive step) 🔗

Even if an invention is technically novel, it can still be revoked on the ground of obviousness – meaning it does not involve an inventive step. Under the Patents Act, an inventive step requires that the invention not be obvious to a person skilled in the relevant field, having regard to what was publicly known or used before the priority date. If a skilled professional in the field could have arrived at the same invention through routine experimentation or logical deduction from existing knowledge, the patent is vulnerable on this ground. In Bajaj Auto Ltd. v. TVS Motor Company (2009), the Madras High Court examined this ground closely in the context of a two-wheeler engine design patent, reinforcing that patents must represent a genuine technical advance beyond the obvious.

Non-usefulness (lack of utility) 🔗

A patent can be revoked if the invention is not useful – meaning it does not have industrial applicability or does not work as described in the specification. The Patents Act requires that an invention be capable of industrial application, which is broadly understood to mean that it can be made or used in some kind of industry. An invention that is purely theoretical, cannot be reproduced, or does not achieve the claimed result is liable to be revoked on this ground. Utility is not a high bar in Indian patent law, but a patent that openly fails to deliver any practical benefit cannot survive scrutiny.

Insufficient description or disclosure in the specification 🔗

This ground strikes at the core of the patent bargain – the inventor receives a monopoly in exchange for fully disclosing the invention to the public. If the complete specification does not describe the invention clearly and completely enough for a person skilled in the relevant field to reproduce it, the patent can be revoked. This includes failure to disclose the best method of working the invention. A patent that keeps crucial details vague or incomplete defeats the public benefit purpose of the patent system and is therefore revocable. Sufficiency of description is a technical and legal question that often requires expert evidence in revocation proceedings.

Failure to disclose information or false suggestion 🔗

A patent may also be revoked if it was obtained by fraud, false suggestion, or non-disclosure of material information. If the applicant concealed prior art, made misrepresentations about the invention, or failed to disclose the geographical origin of biological material used in the invention, these constitute grounds for revocation. This ground maintains the integrity of the patent system by ensuring that monopoly rights are not secured through dishonest means.

Prior secret use 🔗

If the invention was secretly used in India before the priority date of the patent claim by the patentee or their predecessor – for purposes other than reasonable trial or experimentation – it constitutes a ground for revocation. The distinction here is important: the use must have been more than experimental. Secret commercial exploitation of an invention, followed by a patent application, is treated as an abuse of the patent process.

Revocation beyond Section 64: sections 65, 66, and 85 🔗

While Section 64 is the primary provision, the Patents Act provides additional revocation mechanisms. Under Section 65, the Central Government can direct the Controller to revoke a patent if the invention relates to atomic energy, since such inventions cannot be patented under the Atomic Energy Act, 1962. Under Section 66, the Central Government has the power to revoke a patent by a declaration in the Official Gazette if it is satisfied that the patent or the way it is being exercised is mischievous to the State or prejudicial to the public. This provision was applied in the well-known Avesthagen case, where a patent over a medicinal composition involving traditional Indian plants was revoked after questions arose about appropriation of traditional knowledge. Finally, Section 85 allows for revocation for non-working – where the patented invention has not been worked in India even after a compulsory licence has been in place for two years, and public requirements remain unmet.

Revocation as a defence in infringement suits 🔗

In the context of patent litigation, the grounds under Section 64 take on additional practical importance. When a patentee initiates an infringement suit, the defendant has the option to file a counterclaim for revocation before the High Court. This is not merely a technical procedural move – it is a substantive challenge that, if successful, eliminates the plaintiff’s patent entirely. Raising revocation as a defence essentially puts the patentee on trial: they must now defend not just the infringement allegation, but the very existence and validity of their patent. This makes a thorough understanding of revocation grounds indispensable for anyone involved in patent litigation, from either side of the dispute.

It is worth noting that a person who has already initiated post-grant opposition proceedings under Section 25(2) may face restrictions in simultaneously pursuing a revocation petition under Section 64(1), given the opening words of Section 64(1) – “subject to the provisions contained in this Act.” Courts have interpreted this to mean that the two proceedings cannot run in parallel for the same party in respect of the same patent.

Key judicial landmarks 🔗

Indian courts have consistently applied revocation grounds rigorously. In Novartis AG v. Union of India (2013), the Supreme Court’s refusal to grant a patent for a modified form of Imatinib (Gleevec/Glivec) under Section 3(d) sent a clear signal against pharmaceutical “evergreening.” In Monsanto Technology LLC v. Nuziveedu Seeds Ltd. (2018), Monsanto’s patent on Bt cotton seed technology was challenged on the ground of non-patentable subject matter, with the Delhi High Court holding that the patent related to a biological process falling under Section 3(j). These cases illustrate that revocation proceedings in India are far from mere procedural exercises – they have reshaped entire industries and defined the boundaries of what can and cannot be owned through a patent.

What do you think? Given that the same grounds used to revoke a patent can also be raised as a defence in an infringement suit, do accused infringers in India have a structural advantage in patent litigation? And should the threshold for “insufficient disclosure” be more precisely defined in the law to reduce uncertainty in revocation proceedings?

References

1. https://www.ipandlegalfilings.com/revocation-of-patents/
2. https://www.mondaq.com/india/patent/839518/revocation-of-patent-in-india
3. https://www.khuranaandkhurana.com/2017/02/13/revocation-of-patents-according-to-indian-patent-act-1970-insight/
4. https://www.mondaq.com/india/patent/1617256/patent-revocation-grounds-process-legal-framework
5. https://www.waterandshark.com/en-in/blog/understanding-the-grounds-for-patent-revocation-in-india