Summary
The Delhi High Court held that a revocation petition under Section 64 of the Patents Act is distinct from an invalidity defence under Section 107 and remains valid post-patent expiry. The Court emphasized the broader legal impact of revocation, affirming its maintainability even when the patent has lapsed.
Introduction
The Delhi High Court, in Macleods Pharmaceuticals Ltd. v. Boehringer Ingelheim Pharma GmbH & Co. KG, addressed two crucial aspects of patent law: (i) the distinction between a revocation petition under Section 64 of the Patents Act, 1970, and an invalidity defence in an infringement suit under Section 107, and (ii) the maintainability of a revocation petition for an expired patent. The Court asserted that revocation under Section 64 is a separate and independent remedy from an invalidity defence under Section 107, carrying broader legal implications. The Court further clarified that a revocation petition can be filed or sustained even after a patent has expired, provided there is a pending infringement suit or a continuing legal interest.
Background of the Suit
Macleods Pharmaceuticals Ltd. (“Macleods”) initiated a revocation petition before the Delhi High Court, challenging the validity of Indian Patent IN 243301, granted to Boehringer Ingelheim Pharma GmbH & Co. KG (“Boehringer”) for its anti-diabetic drug, LINAGLIPTIN. The petition was filed on February 17, 2022, ahead of Macleods’ planned launch of its generic version of the drug.
Following the revocation petition, Boehringer filed an infringement suit against Macleods before the High Court of Himachal Pradesh on February 19, 2022 (“Himachal suit”). In its defence, Macleods raised a plea of invalidity under Section 107 of the Patents Act.
Boehringer sought dismissal of the revocation petition, arguing that it was filed twelve years after the grant of the patent. The Delhi High Court, however, rejected this argument, clarifying that the Patents Act does not impose any statutory time limit for initiating a revocation petition.
Arguments by Boehringer
Boehringer raised strong procedural objections to the maintainability of the revocation petition. They argued that Macleods had already invoked patent invalidity as a defence under Section 107 of the Patents Act in the infringement suit pending before the Himachal Pradesh High Court. In Boehringer’s view, this rendered a parallel revocation petition unnecessary and potentially problematic.
Boehringer contended that the reliefs sought in both proceedings were substantially similar and that permitting both to proceed could result in conflicting judgments from different High Courts. They submitted that finding of invalidity, whether in a revocation petition or an infringement suit, is a finding in rem that universally applies to all parties. Given that an infringement suit entails a more comprehensive examination of evidence, they argued that adjudicating a separate revocation petition would be redundant. With the expiry of the patent on August 18, 2023, Boehringer also argued that Macleods no longer qualified as a person interested under Section 2(1)(t) of the Patents Act.
Arguments by Macleods
Macleods argued that invoking Section 107 of the Patents Act as a defence in an infringement suit has distinct legal and practical implications compared to filing a revocation petition under Section 64. While Section 107 allows a defendant to challenge the validity of specific claims, it does not grant the right to seek full revocation of the patent.
Further, even if some claims are invalidated in an infringement suit, valid claims can still be enforced against third parties under Section 114. In contrast, a revocation petition under Section 64 applies to the entire patent and can lead to the removal of the patent from the Register of Patents. Section 64 provides a stand-alone right to file a revocation petition at any time, even after a patent has expired, as there is no statutory time limit. Additionally, since a patentee can claim damages post-expiry, the right to seek revocation should also survive beyond the patent’s term.
Analysis and Judgment by the Court
The Court clarified two key legal questions in its judgement.
(I) Maintainability of revocation petition despite the invalidity defence in the infringement suit
The Court upheld the maintainability of the revocation petition, highlighting the fundamental distinctions between revocation under Section 64 and the invalidity defence under Section 107 of the Patents Act. It observed that a revocation petition seeks the complete removal of a patent from the Register of Patents, whereas an invalidity defence merely renders the patent liable for revocation, necessitating additional steps for its removal from the register.
The Court further noted that under Section 58 of the Act, the High Court has the discretion to allow amendments to the patent specification instead of outright revocation, an option not available in an invalidity defence under Section 107.
Additionally, the Court clarified that findings in a suit between two parties apply only to the contesting parties (in personam) and specifically observed that “Under Section 114 of the Patents Act, even when certain claims have been held to be invalid in a patent infringement suit, the Court may grant relief in respect of any valid claims which are infringed. The finding of invalidity given by the Court would not have a direct bearing in a suit filed by the patentee against third parties.” But on the other hand, a revocation order under Section 64 would operate in rem, preventing the patentee from asserting any claims in the patent against any third party.
The Court also upheld the petitioner’s right to independently pursue revocation proceedings. It clarified that filing a defence under Section 107 does not preclude a petitioner from independently seeking revocation under Section 64.
(II) Can a revocation petition be filed or sustained after the expiry of the term of the patent
The Court observed that expiration of a patent does not render an infringement suit or a revocation petition infructuous. It noted that legal remedies remain available for actions initiated during the life of the patent. Accordingly, Boehringer’s infringement suit, which seeks damages for alleged infringement while the patent was still in force, remains unaffected by the patent’s expiry. Extending the same reasoning, the Court affirmed that a revocation petition cannot be dismissed merely on the ground that the patent has lapsed. The Court concluded the petition be maintainable, since Macleods had initiated the revocation during the subsistence of the patent.
Conclusion
The Delhi High Court dismissed the application filed by Boehringer seeking the rejection of the revocation petition, affirming its maintainability and sustainability.
Citation: Macleods Pharmaceuticals Ltd vs The Controller of Patents & Anr., C.O.(COMM.IPD-PAT)38/2022 (H.C. Delhi January 15, 2025)
Available at: https://indiankanoon.org/doc/83528155/
Article Review: Dr. Kalyan C. Kankanala
Accessibility Review: Kavya Sadashivan
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