Revocation Plea Maintainable Despite Patent Expiry: Delhi HC

ENA Sectors 2026-02-26 16:19:18 New Delhi, Feb 26 (KNN) The Delhi High Court has ruled that the expiry of a patent does not make a pending revocation petition meaningless. The Court ruled that a revocation plea can continue even after a patent has lapsed due to the passage of time. A Division Bench of Justice C. Hari Shankar and Justice Om Prakash Shukla on Tuesday held, A revocation petition would be maintainable, and would continue to survive, even after the patent of which revocation is sought expires by efflux of time. Once revoked, the patent is rendered ineffective and incapable of assertion ab initio, the court further clarified. Background of the Case The decision came in an appeal filed by Boehringer Ingelheim Pharma GmbH & Co. KG against an order permitting a revocation petition filed by Macleods Pharmaceuticals Limited to proceed. Boehringer argued that its patent for the drug Linagliptin had expired in August 2023 and that continuing the revocation proceedings served no purpose. It further contended that since Macleods had raised an invalidity defence under Section 107 of the Patents Act in a separate infringement suit, it could not maintain a separate revocation petition under Section 64. Courts Observations Rejecting these arguments, the Bench held that a patent remains a patent granted under the law even after expiry. While expiry makes a patent unenforceable, it does not remove its legal character. Therefore, a revocation petition remains maintainable. The Court clarified that Sections 107 and 64 of the Patents Act operate in distinct legal spheres. A Section 107 defence allows a party to challenge validity within an infringement suit. In contrast, a Section 64 petition seeks cancellation of the patent itself. If allowed, the patent is rendered void from the outset and unenforceable against all. Referring to the Supreme Courts ruling in Aloys Wobben v. Yogesh Mehra, the Bench stated that a statutory bar applies only where a counter-claim for revocation has been filed in the infringement suit. Raising an invalidity defence alone does not prevent filing a separate revocation petition. Appeal Dismissed The Court noted that Macleods continued to have a real and live interest in challenging the patents validity, particularly in view of the damages claim in the infringement proceedings. It accordingly dismissed Boehringers appeal and allowed the revocation petition to continue. Impact on MSMEs The ruling has implications for MSMEs, especially in the pharmaceutical and manufacturing sectors. By clarifying that expiry does not bar revocation, the Court has affirmed that a patent may still be invalidated retrospectively under the Patents Act, 1970 even after it lapses. For MSMEs facing infringement claims or damages, this means they may continue challenging a patents validity to limit past liability and reduce legal uncertainty. At the same time, MSMEs holding patents may remain open to revocation challenges even after expiry, extending potential legal exposure. (KNN Bureau) 45290 https://knnindia.co.in/news/newsdetails/sectors/revocation-plea-maintainable-despite-patent-expiry-delhi-hc 2026-02-26 16:19:18 knnindia.co.in Revocation Plea Maintainable Despite Patent Expiry: Delhi HC