Grounds for Patent Revocation: Ensuring Patents Meet Legal Standards

A patent, once granted, is not permanent by default – it can be challenged and taken away if it turns out the grant should never have happened in the first place. This is what patent revocation means: the legal cancellation of a granted patent on the basis that it fails to meet the standards the law demands. In India, the Patents Act, 1970 lays down a detailed framework for this, primarily through Section 64, which lists the grounds on which any interested party or the Central Government can seek revocation. Understanding these grounds is essential – not just for defending a patent you hold, but for challenging one that shouldn’t exist.

What is revocation of a patent? 🔗

Patent revocation is the statutory process by which a granted patent is declared invalid and cancelled, either wholly or in part. The Indian patent system does not presume that every granted patent is valid. Third parties who are required to seek permission from the patentee for using the patented invention are also given the right to challenge its validity. As Khurana & Khurana note, this challenge can be brought independently or in response to an infringement action initiated by the patentee. Revocation, therefore, works both as a proactive remedy and as a defensive tool in patent litigation.

Once a patent is revoked, the invention effectively re-enters the public domain – anyone can use it without seeking permission or paying royalties. This makes revocation one of the most powerful checks in the patent system.

Who can initiate revocation proceedings? 🔗

Under Section 64 of the Patents Act, 1970, revocation can be sought by any interested person or the Central Government. Indian courts have interpreted “interested person” broadly – it includes anyone whose commercial, research, or industrial interests are affected by the existence of the patent. Revocation can be initiated through three routes:

• A petition to the High Court at any time during the 20-year patent term (this function was earlier with the IPAB, which has since been abolished)
• A counterclaim in an infringement suit before the High Court – when a patentee sues for infringement, the defendant may counter-attack by seeking revocation
• A petition by the Central Government in matters involving public interest

It is also worth noting that Section 25(2) provides for post-grant opposition, which must be filed within one year of the publication of the patent grant. While it shares many grounds with Section 64, it is a distinct proceeding before the Patent Controller and is more restrictive in scope.

Grounds for revocation under Section 64 🔗

Section 64 provides a comprehensive – and importantly, non-exhaustive – list of grounds for revocation. Each ground targets a different kind of defect in the patent. Here are the most significant ones:

Prior claiming – the invention was already patented 🔗

A patent can be revoked if the claimed invention was already covered by a valid earlier patent in India with an earlier priority date. This ensures that two patents cannot exist for the same invention simultaneously. If a later patent essentially duplicates an earlier one, the later grant is legally unsustainable and liable to be struck down.

Lack of novelty (anticipation) 🔗

Every patentable invention must be new – it must not form part of the “state of the art” at the time of filing. If the invention was already disclosed publicly, through prior publications, prior use, or even knowledge available within any local or indigenous community in India or elsewhere, the patent is vulnerable to revocation on the ground of lack of novelty. This is one of the most commonly invoked grounds in revocation proceedings.

Obviousness – absence of an inventive step 🔗

An invention that is obvious to a person skilled in the relevant field does not deserve patent protection. Obviousness, or the lack of an inventive step, means that the claimed invention is merely a straightforward extension of what was already known – something that a technically skilled person would arrive at without any creative leap. A patent granted for something obvious distorts market competition and stifles genuine innovation.

Non-patentable subject matter 🔗

If the invention falls into a category that is expressly excluded from patentability under the Act, it can be revoked. Section 3 of the Patents Act provides an extensive list of non-patentable subject matter, including discoveries of natural phenomena, mathematical methods, business methods, and mere new uses of known substances. Section 3(d), in particular, has been a critical provision in pharmaceutical patent disputes – it prevents the grant of patents for new forms of known substances unless the new form demonstrates significantly enhanced efficacy.

The landmark Supreme Court decision in Novartis AG v. Union of India (2013) is the defining case here. Novartis sought a patent for Gleevec (imatinib mesylate), a cancer drug that was a modified form of a previously known compound. The Supreme Court rejected the patent under Section 3(d), holding that the modification did not show enhanced therapeutic efficacy. The Court’s ruling firmly shut the door on “evergreening” – the practice of making minor tweaks to existing drugs to extend patent monopoly – setting a precedent that continues to shape pharmaceutical patent law in India.

Wrongful obtaining of the patent 🔗

A patent can be revoked if it was obtained by a person who had no right to apply for it – for example, if the patent was taken out in the name of someone who did not actually invent the claimed invention, or if it was secured by wrongfully appropriating the invention from the true inventor. The person who is actually entitled to the patent may petition for revocation on this ground.

Insufficient disclosure in the specification 🔗

This ground goes to the heart of the bargain underlying patent law: in exchange for a limited monopoly, the patentee must fully disclose the invention so that the public can understand and, once the patent expires, reproduce it. If the complete specification does not sufficiently and fairly describe the invention, or does not disclose the best method of performing it, the patent can be revoked. A patent whose specification is vague, misleading, or incomplete fails to fulfill its end of this bargain and cannot be allowed to stand.

Claim scope exceeds the disclosure 🔗

If the scope of any claim in the complete specification is wider than what the invention described actually justifies, the patent is vulnerable to revocation. The claims define the legal boundaries of protection – they cannot be drafted to grab more territory than the disclosed invention supports. Overclaiming is a ground for revocation because it unfairly extends the patentee’s monopoly beyond what was actually invented.

Secret use before the date of filing 🔗

If the invention was secretly used in India before the date of the patent application by or with the knowledge of the true and first inventor, this can constitute a ground for revocation. This provision prevents inventors from commercially exploiting their invention in secret for a period before filing, and then using the patent to prevent others from entering the market after the filing date.

Grant to a person not entitled to apply 🔗

The Patents Act provides specific rules about who is entitled to apply for a patent. If a patent was granted in contravention of these rules – for instance, to someone other than the inventor or their assignee – it is liable to be revoked. This ground upholds the integrity of the entitlement rules built into the patent application process.

Revocation in public interest – Section 66 🔗

Beyond the grounds in Section 64, Section 66 arms the Central Government with a distinct power: to revoke a patent if it is satisfied that the patent or the manner in which it is exercised is mischievous to the State or prejudicial to the public. Before doing so, the government must give the patentee an opportunity to be heard.

A well-known example is the revocation of Avesthagen’s patent for a medicinal formulation involving jamun, on the grounds that it was derived from traditional knowledge and that its continued existence was prejudicial to the public. This provision also served as the basis for challenges to patents on neem and turmeric in the 1990s – patents granted abroad that drew on centuries of indigenous Indian knowledge. Section 66, in this sense, acts as a safeguard for traditional knowledge and public health.

Revocation for non-working – Section 85 🔗

A patent comes with an obligation: the invention must actually be worked in India. Under Section 85, a patent can be revoked for non-working if, even after two years from the date of the first compulsory licence being granted, any of the following conditions persist:

• The patented invention has not been worked in India
• The reasonable requirements of the public have not been met
• The invention is not available to the public at a reasonably affordable price

The application may be filed by the Central Government or any interested person before the Controller. This provision reflects the policy that a patent is not meant to be a tool for sitting on an invention while blocking others – the monopoly granted by the State is conditional on genuine exploitation of the technology for public benefit.

Revocation for atomic energy – Section 65 🔗

Section 65 provides that if a patent is found to relate to an invention relevant to atomic energy, the Central Government may direct the Controller to revoke it. Patents for atomic energy inventions are not permissible under the Atomic Energy Act, 1962, which vests control over all such matters exclusively in the State. A patent inadvertently granted in this area must therefore be revoked.

How revocation interacts with infringement proceedings 🔗

One of the most strategically significant aspects of patent revocation is its role in infringement litigation. Under Section 104 of the Patents Act, no suit for patent infringement can be filed in a court below the level of a District Court. If, in such a suit, the defendant files a counterclaim for revocation of the patent, the entire matter – including the infringement suit – is transferred to the High Court. This reflects the seriousness with which the law treats revocation: it is not just a defensive tactic but a substantive challenge that elevates the jurisdiction of the dispute.

The same grounds that can be used to seek revocation can equally be raised as a defence in infringement proceedings. A defendant accused of infringement can argue that the patent being enforced against them is invalid – because the invention lacked novelty, or was obvious, or was not sufficiently disclosed. If the court accepts any of these grounds, the patent falls and the infringement action along with it.

The purpose behind these legal checks 🔗

The grounds for patent revocation are not arbitrary hurdles – they are calibrated to ensure that the patent system serves its fundamental purpose: incentivising genuine innovation while preventing monopolistic abuse. When a patent fails to meet standards of novelty, inventive step, or sufficient disclosure, it is not just a technical deficiency. It represents a situation where the State has handed a private party a monopoly that the public did not truly bargain for. Revocation corrects that situation. The legal framework, taken as a whole, strikes a balance: it protects legitimate inventors while keeping an active check against patents that should never have been granted, or that have outlived their legal justification.

What do you think? If a competitor holds a patent on a technology that appears to be based entirely on prior art known in the industry for decades, what legal route would be most effective to challenge it – and at what stage of the patent’s life would such a challenge carry the most weight? Also, given India’s rich tradition of indigenous knowledge, do you think the current provisions under Section 66 are sufficient to protect traditional knowledge from being wrongly patented?

References

1. https://ipindia.gov.in/patents.htm
2. https://www.khuranaandkhurana.com/2017/02/13/revocation-of-patents-according-to-indian-patent-act-1970-insight/
3. https://ipindia.gov.in/writereaddata/Portal/ev/sections/ps64.html
4. https://www.ipandlegalfilings.com/revocation-of-patents/
5. https://legislative.gov.in/sites/default/files/A1970-39.pdf
6. https://ipindia.gov.in/writereaddata/Portal/ev/sections/ps66.html
7. https://ipindia.gov.in/writereaddata/Portal/ev/sections/ps85.html
8. https://dae.gov.in/
9. https://www.lexology.com/library/detail.aspx?g=3d2f2c0f-d543-4374-9667-d0f4f7ed40a7
10. https://www.mondaq.com/india/patent/1617256/patent-revocation-grounds-process-legal-framework