The Delhi High Court has held that a revocation petition can be filed or sustained after the expiry of the term of the subject patent when there is a valid cause of action in favour of the petitioner.

The Court was considering Interlocutory Applications filed seeking dismissal of the Revocation Petition by Macleods Pharmaceuticals Ltd.

The single- bench of Justice Amit Bansal observed, "The Himachal Suit filed by the respondent no.2 is still continuing despite the term of the patent having expired. If the petitioner succeeds in the present petition and the subject patent is revoked, the suit of the respondent no. 2 would be liable to be dismissed. Therefore, there is a valid cause of action in favour of the petitioner to pursue the present petition and simply because the life of the patent has expired, would not mean that the present petition becomes infructuous.....Therefore, I am of the opinion that the present petition can be sustained even after the expiry of the subject patent."

The Applicant (Respondent) was represented by Senior Advocate Sandeep Sethi while the Petitioner was represented by Advocate G. Nataraj.

Facts of the Case

The Revocation Petition was filed by the Petitioner under Section 64(1) of the Patents Act, 1970 seeking revocation of Indian Patent IN 243301 registered in the name of the Respondent in respect of a medicinal product called ‘LINAGLIPTIN’, an anti-diabetic product. The subject patent was granted in favour of the respondent on October 05, 2022 with the priority date of August 21, 2002. The present petition was filed on February 17, 2022 just before the intended date for the commercial launch of the petitioner’s generic ‘LINAGLIPTIN’ product, i.e. February 22, 2022. Subsequently, on February 19, 2022, the Respondent filed an infringement suit against the petitioner before the High Court of Himachal Pradesh alleging infringement of the subject patent.

The earlier Application seeking dismissal of the present revocation petition on the ground that it was filed twelve years after the grant of the subject patent was dismissed by Court on the ground that there is no prescribed time limit to file a revocation petition. The Application seeking transfer of the present revocation petition to the High Court of Himachal Pradesh, to be consolidated with the Himachal Suit was also dismissed.

The present Application was eventually filed stating that since the subject patent has expired on 18th August, 2023, nothing survives in the present revocation petition and, therefore, the same should be dismissed.

Reasoning By Court

The Court at the outset considered the legal question as to whether a revocation petition can be held to be not maintainable if the petitioner has 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.

After a detailed analysis of the provision of the Patents Act, it was of the considered view that the scope of a petition under Section 64 of the Patents Act is entirely different from the defence of invalidity under Section 107 of the Patents Act for the reasons set out hereinafter.

"Under Section 64 of the Patents Act, a petition for revocation of the patent can be filed on a stand-alone basis or by way of a counter-claim in an infringement suit. The power to entertain such a revocation petition has been given only to a High Court. On the other hand, in terms of Section 1041 of the Patents Act, a patent infringement suit can be adjudicated by a District Court as well. Consequently, defence under Section 107 of the Patents Act can also be adjudicated by the District Court. However, where a counter-claim has been filed in a patent infringement suit seeking revocation of the patent by the defendant, in terms of proviso to Section 104 of the Patents Act, the suit along with the counter-claim has to be transferred to the High Court," the Court observed.

"A reading of Sub-section (1) of Section 151 of the Patents Act would show that all orders of the High Court on a petition for revocation shall be transmitted to the Controller who shall make suitable entry in the register on the basis of the said order. Once a revocation petition under Section 64 of the Patents Act is allowed, the patent is effaced from the Register of Patents as if it never existed," the Court further observed.

The Court was of the view that based on a finding of invalidity of claims by a competent court on the basis of a defence under Section 107 of the Patents Act, the defendant has a right to take additional steps under Section 71(1)2 of the Patents Act for rectification of the register and hence, a finding of invalidity by itself would not result in removal of the patent from the register.

It was asserted that the effect of the two proceedings is completely different.

"In the present revocation petition, the petitioner is seeking revocation/ removal of the subject patent from the Register of Patents. However, in the Himachal Suit, the petitioner is praying for declaration of invalidity which would render the subject patent “liable to be revoked and removed from Register of Patents” which implies that the defendant/ petitioner herein would need to take additional steps for getting the patent revoked/removed from the Register of Patents," the Court observed.

"This is not a case where the petitioner deliberately chose to file the revocation petition in Delhi after the Himachal Suit had been instituted. The present revocation petition was filed before the Himachal Suit. Further, it is to be noted that the petitioner, though has taken the defences under Section 107 of the Act in its written statement, it has not filed a counter-claim in the suit seeking revocation of the suit patent," the Court pointed out.

The Court concluded that the scope and effect of a revocation petition filed under Section 64 of the Patents Act and the defence of invalidity taken under Section 107 of the Patents Act in an infringement suit is entirely different.

It then went on to answer as to whether a revocation petition can be filed or sustained (if already filed) after the expiry of the term of the patent and accordingly decided in affirmative of the same.

"The respondent no. 2 has filed a patent infringement suit in which it has claimed damages for the alleged infringement of its patent by the petitioner during the life of the patent. Just because the term of the patent has expired, it would not mean that the suit has become infructuous, as the cause of action, insofar as damages are concerned, still survives. Applying the same rationale, it cannot be argued that a revocation petition cannot be filed or will not survive (if filed earlier) after the term of the patent has expired," the Court observed.

The Applications were accordingly dismissed.

Cause Title: Macleods Pharmaceuticals Ltd. vs. The Controller Of Patents & Anr. (2025:DHC:158)

Appearances:

Petitioner- Advocate G. Nataraj, Advocate Rahul Bhujbal, Advocate Yash Ra

Respondent- Senior Advocate Sandeep Sethi, Advocate Sanjay Kumar, Advocate Arpita Sawhney, Advocate Meenal Khurana, Advocate Pallavi Kiran, Advocate Arun Kumar Jana, Advocate Priyansh Sharma, Advocate Pratiksha Varshney, Advocate Sumer Seth, Advocate Riya Kumar

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