The Differing Scope Of Revocations And Invalidity Defences In India

Challenges to patents through revocation petitions can be filed independently or as counterclaims in infringement suits. In infringement suits, a defending party has the option to file a revocation petition or argue that the patent itself is invalid. Many questions arise in these contexts, and the Delhi High Court recently had occasion to clarify precisely some of these, concluding that the scope and effect of a revocation petition filed under Section 64 (which deals with revocation) are different from an invalidity defence raised under Section 107 of the Patents Act ('the Act').

In Macleods Pharmaceuticals Ltd. vs. The Controller of Patents & Anr. (I.A. 7635/2024 and I.A.46685/2024 IN C.O.(COMM.IPD-PAT)38/2022), the Court addressed two issues: firstly, whether a revocation petition is maintainable if the petitioner has filed a written statement, taking defence of the patent's invalidity under Section 107 in an infringement suit; and secondly, whether a revocation