The Delhi High Court has in its Judgement dated 15 January 2025 held that a revocation petition is maintainable even if the petitioner had filed a written statement, taking a defence of invalidity of the suit patent under Section 107 of the Patents Act, in an infringement suit filed by the patentee. The petitioner had filed a written statement seeking invalidity of the subject patent in an infringement suit filed before the Himachal Pradesh High Court by the patentee/respondent (in the present revocation petition).
The High Court has also held that a revocation petition can be filed or sustained (if already filed) after the expiry of the term of the patent.
Revocation petition v. Defence of invalidity
Upholding the maintainability of the revocation petition, the Court in Macleods Pharmaceuticals Ltd. v. Controller of Patents and Anr. observed that the scope of a petition under Section 64 of the Patents Act (for revocation of a patent) is entirely different from the defence of invalidity of the patent under Section 107 of the Patents Act, 1970. The High Court in this regard noted the following:
- Only a High Court can entertain revocation petition while defence of invalidity can also be adjudicated by District Court.
- A finding of invalidity by itself would not result in removal of the patent from the register, while the patent is effaced from the Register of Patents as if it never existed if a revocation petition is allowed. Section 151 was relied upon.
- In revocation proceedings the High Court can allow the patentee to amend the specification instead of revoking the patent, while based on a defence under Section 107, the Court cannot direct the patentee to amend the claims in a patent.
- Revocation of patent operates in rem, while findings of invalidity only bind the contesting parties, i.e., are in persona.
- Party to choose whether to file a revocation petition on a stand-alone basis under Section 64 or file a counter claim in a pending suit. Provisions do not suggest that in an infringement suit, the defendant can only use the defence under Section 107 or file a counterclaim.
- Revocation petition was filed before the Delhi High Court after the infringement suit was filed in Himachal Pradesh High Court.
- Transfer petition for transfer of infringement suit to Delhi HC pending before the Supreme Court.
Revocation petition after expiry of patent
Holding that the present revocation petition was sustainable even after the expiry of the subject patent, the Court noted the following:
- Infringement suit does not become infructuous after expiry of the term of the patent as cause of action concerning damages still survives.
- Infringement suit before the Himachal Pradesh HC was continuing despite the expiry of the term of the patent.
- Valid cause of action in favour of petitioner to pursue present revocation petition because if the petitioner succeeds and the subject patent is revoked, the suit of the respondent/patentee would be liable to be dismissed.