Delhi High Court Clarifies Patent Revocation Rights: Expired Patents Can Be Revoked, Section 107 Defence Does Not Bar Revocation Petition
Summary The Delhi High Court Division Bench held that patent revocation petitions under Section 64 of the Patents Act remain maintainable even after patent expiry, and that filing a Section 107 invalidity defence in an infringement suit does not preclude a separate revocation petition. The Court emphasized that revocation operates retrospectively and in rem (affecting all parties), while Section 107 defence operates only in personam (between specific parties), making them fundamentally distinct remedies serving different purposes. Factual Background In February 2022, Macleods Pharmaceuticals filed a revocation petition under Section 64 of the Patents Act, 1970 seeking to invalidate Boehringer Ingelheim's Indian Patent IN'243301 covering the pharmaceutical compound Linagliptin (a diabetes medication). Two days after the revocation petition was filed, Boehringer Ingelheim initiated infringement proceedings against Macleods before the Himachal Pra...