Introduction
Patents grant exclusive rights to inventors for a specific period, but this exclusive right can be contested if a party believes that the patent was erroneously granted. The Indian Patents Act of 1970 (“Act”) provides the mechanisms for challenging the validity of patents through revocation petitions. One of the primary concerns is whether certain actions, such as filing a written statement in an infringement suit or the expiration of the patent term, impact a party’s ability to file or sustain a revocation petition. These questions are central to the proceedings in a recent decision of the Delhi High Court in Macleods Pharmaceuticals Ltd. vs. The Controller of Patents & Anr. (2025) [1].1 In this blog, we will delve deeper into this aspect.
Background
Macleods Pharmaceuticals Ltd. (Petitioner) is a pharmaceutical company that manufactures and markets anti-diabetic drugs and other pharmaceutical products. Macleods filed a revocation petition under Section 64(1) of the Act, to challenge the validity of Indian Patent IN 243301, granted on October 5, 2010, to Boehringer Ingelheim Pharma GmbH & Co. KG (Respondent).
Interestingly, the Petitioner filed the revocation petition on February 17, 2022, just before the launch of its generic version of the product on February 22, 2022. In response, the Respondent filed an infringement suit against the petitioner in the High Court of Himachal Pradesh (COMS 3/2022) on February 19, 2022.
On May 4, 2022, the Respondent sought to dismiss the petition, arguing that it was filed twelve years after the patent was granted. Accordingly, the petition was dismissed on July 27, 2022. The Respondent also filed a transfer application (I.A. 13077/2023) to transfer the revocation petition to the Himachal Pradesh High Court, but this was also dismissed on July 20, 2023.
The patent then expired on August 18, 2023. On April 2, 2024, the Respondent filed a second application (I.A. 7635/2024) to dismiss the revocation petition, arguing that it was no longer relevant. On May 8, 2024, the petitioner filed a transfer petition before the Supreme Court, requesting to transfer the Himachal Pradesh suit to this Court. Said case is still pending.
On November 25, 2024, the Respondent filed a third application (I.A. 46685/2024) to dismiss the revocation petition on the grounds that the petitioner had already filed a written statement in the Himachal Pradesh suit and had challenged the validity of the patent.
Issues
- Can a revocation petition be dismissed as not maintainable if the petitioner has already filed a written statement in an infringement case, where the petitioner argues that the patent in question is invalid under Section 107 of the Patents Act of 1970?
- Can a revocation petition be filed, or remain valid if it has already been filed, after the patent has expired?
Respondent’s Contentions
The Respondent argued that the Petitioner had already raised the defense of patent invalidity under Section 107 of the Act in a written statement filed in a separate infringement suit before the Himachal Pradesh High Court. They contended that the claims made in the revocation petition under Section 64 are similar to those raised in the written statement. This makes the petition redundant. According to the respondent, a finding of invalidity in either a revocation petition or an infringement suit has the same effect, which means it universally binds and conclusively settles the rights related to the patent.
The Respondent further emphasized that an infringement suit under Section 104 is a detailed process which includes evidence from both sides that renders the revocation petition unnecessary.
Moreover, the patent had expired on August 18, 2023. The Petitioner no longer qualified as a “person interested” under Section 2(1)(t). Citing Dr. Reddy’s Laboratories Limited vs. Controller of Patents (2022) [2]2, the Respondent argued that once a patent expires, petitioner cannot challenge it through a revocation petition.
Petitioner’s Contentions
The Petitioner contended that a revocation decision under Section 64 can only be made by a High Court. However, invalidity based on a defense under Section 107 can be decided by a District Court. Section 107 allows a defendant to challenge the validity of a patent in an infringement suit, but it does not allow for outright revocation of the patent.
The Petitioner further contended that the relief sought in the revocation petition is broader than what was requested in the infringement suit. They highlighted that under Section 114, even if some patent claims are invalid, valid claims can still be enforced against other parties.
Furthermore, the Petitioner contended that a revocation petition under Section 64 is not time-barred and can be filed even after the patent’s expiry. The rights under a patent, like compensation for damages, survive after the expiry of the patent. Therefore, the right to file a revocation petition should also survive.
The Verdict
- According to the Indian Patent Act, 1970, a party has the choice to file a revocation petition under Section 64 or a counterclaim in an infringement suit.
- There is no limitation on filing a revocation petition after the infringement suit has been filed.
- Under Section 64, a person who has an interest in a patent can ask to revoke it, even if the patent’s validity period has ended.
- The person requesting in this case, the Petitioner, is “interested” because they were making and selling the same type of product that was patented. Because of this, the Petitioner had the right to request the patent’s cancellation.
Ratio Decidendi
The court found that a revocation petition under Section 64 is maintainable even if the defendant in an infringement case has already taken a defense under Section 107. According to the court, a revocation petition raises doubts about the validity of the patent and may result in its deletion from the Register of Patents. On the other hand, a defense under Section 107 only contests the enforceability of the patent in the specific infringement suit. The court also held that a revocation petition can be filed by a party accused of patent infringement. This can be done separately from the infringement proceedings. It noted that the Act does not compel a party to raise a counterclaim for revocation within the infringement suit, instead, they can pursue the revocation separately.
The court noted that a revocation petition can be filed even after the patent term has expired, provided the petitioner qualifies as a “person interested” under Section 2(1)(t). The “person interested” includes individuals or entities involved in activities related to the patented product or process.
The court determined that if a revocation petition is successful, the patent will be completely removed from the Register of Patents. In contrast, a finding of invalidity under Section 107 does not result in the patent’s removal but only limits its enforceability in the specific suit.
Our Analysis
This case highlights the independence of a revocation petition under Section 64 from the defenses raised under Section 107 in an infringement suit. While Section 107 addresses the specific enforceability of a patent in an infringement suit, Section 64 allows for a broader challenge to its validity. The court acknowledged that a revocation petition serves a broader purpose beyond resolving disputes between parties. It plays a crucial role in ensuring that only genuine inventions are retained in the Register of Inventions.
By permitting these petitions, the court clarified that the expiry of a patent does not render a revocation petition invalid, provided the petitioner qualifies as a “person interested” under Section 2(1)(t). This approach ensures that patents that fail to meet the statutory requirements for validity can still be removed.
The court, while deciding this case, referred to the case of Dr. Reddy’s Laboratories Limited [2], that interpreted the term “person interested” as defined under Section 2(1)(t) includes the following, and clarified that a patent can be revoked even after its expiry, by a person interested, as long as there is a valid interest in challenging its validity.
- A person wishing to manufacture or sell the patented product or a product using the patented process.
- A person against whom a suit for infringement has been filed.
- A person interested in the invention covered by the patent in any other manner.
Conclusion
From this ruling, it has been established that a revocation petition can still be maintained even after a patent expires. Additionally, filing a written statement in an infringement suit does not prevent a party from pursuing a revocation petition separately. If anyone is accused of infringing a patent, they can defend themselves in the infringement case and still have the option to file a revocation petition to challenge the patent’s validity. Thus this ruling protects the rights of individuals and businesses by making sure that invalid patents can be challenged and removed at any time.
References