The Delhi High Court’s judgment in Novo Nordisk A/S v. Dr Reddy’s Laboratories Limited delivers a sobering reminder that courts must not expend scarce judicial resources on patent disputes where the patent is on the verge of expiry and no meaningful relief can be granted. Beyond procedural prudence, the Court clarified the legal standard for assessing obviousness under the Patents Act, 1970, and reinforced that a credible challenge to patent validity at the interim stage requires no exhaustive trial - but only a prima facie showing that the invention is obvious to a person skilled in the art.
Background & Facts
The Dispute
The appellant, Novo Nordisk A/S, holds Indian Patent No. 262697 for Semaglutide, a long-acting anti-diabetic drug marketed as Wegovy and Rybelsus. The patent’s priority date is 18 March 2005, and it was set to expire on 20 March 2026. In December 2024, Novo Nordisk discovered that Dr Reddy’s Laboratories was importing Semaglutide. On 26 May 2025, Novo Nordisk filed a suit for patent infringement and sought an interim injunction to restrain the respondents from selling the drug.
Procedural History
- 26 May 2025: Suit filed before the Delhi High Court’s Intellectual Property Division.
- 29 May 2025: Respondents undertook not to sell Semaglutide in India, a restraint that remained in force.
- 2 December 2025: Learned Single Judge rejected the application for interim injunction, holding that the patent was vulnerable to revocation under Section 64(1)(f) of the Patents Act due to obviousness.
- January 2026: Appeal filed before the Division Bench, with only two months remaining before patent expiry.
Relief Sought
The appellant sought an interim injunction to prevent the respondents from manufacturing or selling Semaglutide until final adjudication of the suit. The respondents opposed the injunction on the ground that the patent was invalid due to lack of novelty and inventive step.
The Legal Issue
The central question was whether the invention claimed in the patent for Semaglutide was obvious to a person skilled in the art, having regard to the teachings of prior art, and whether such a finding sufficed to defeat an application for interim injunction under Order XXXIX of the CPC.
Arguments Presented
For the Appellant
Novo Nordisk argued that Semaglutide was a novel compound with three specific modifications to the GLP-1 peptide sequence, none of which were explicitly disclosed in the prior art patent IN’964. It contended that substitution of alanine with α-aminoisobutyric acid (Aib) at position 8 involved a non-obvious technical advance, as Aib is a non-proteogenic amino acid with distinct pharmacological properties. It relied on F. Hoffmann-La Roche Ltd v. Cipla Ltd (Roche-II) to argue that a detailed five-step test for obviousness must be applied, and that the Single Judge erred in concluding obviousness without full evidence.
For the Respondent
Dr Reddy’s contended that the prior art patent IN’964, a genus patent, disclosed a Markush structure encompassing Semaglutide. Claim 16 of IN’964 specifically identified Aib as the preferred amino acid at position 8, and Claim 21 exemplified a compound with the same modifications at positions 26 and 34. The respondents argued that a person skilled in the art, guided by these disclosures, could easily substitute Ala with Aib to arrive at Semaglutide without inventive step. They relied on Novartis AG v. Union of India and AstraZeneca AB v. Intas Pharmaceuticals Ltd to support the view that common inventors and overlapping disclosures negate inventiveness.
The Court's Analysis
The Court began by acknowledging the procedural impropriety of hearing an appeal on an injunction when the patent was days from expiry. It emphasized that courts must apply the principles of balance of convenience and irreparable loss even in intellectual property cases, and that appeals against interlocutory orders are appeals on principle, not on merits (Wander Ltd v. Antox India).
The Court then turned to the substantive issue. It disagreed with the Single Judge’s application of Section 64(1)(a) (anticipation by prior claim), noting that this provision requires identity of claims - not structural similarity or enablement. However, the Court found that the very reasoning used by the Single Judge to reject the patent under Section 64(1)(a) actually established a prima facie case under Section 64(1)(f) (obviousness).
"The findings returned by the learned Single Judge, for holding a prima facie case to have been made out under Section 64(1)(a), in fact make out a prima facie credible challenge to the validity of the suit patent under Section 64(1)(f)."
The Court held that the Single Judge’s analysis - showing that IN’964 disclosed the same modifications at positions 26 and 34, and that Claim 16 explicitly preferred Aib at position 8 - demonstrated that a person skilled in the art could combine these teachings to arrive at Semaglutide. The substitution of Ala with Aib was not an inventive leap but a predictable modification within the scope of the genus patent.
The Court further endorsed the "person in the know" test from AstraZeneca v. Intas, noting that since five inventors were common to both patents, the standard should be higher than the ordinary "person skilled in the art." Even under this stricter lens, the invention was obvious.
The Court declined to apply the five-step Roche-II test at the interim stage, citing Brihan Karan Sugar Syndicate, which cautions against mini-trials on interlocutory applications. A prima facie showing of obviousness, based on clear prior art disclosures, was sufficient.
The Verdict
The appeal was dismissed. The Court held that the respondents had made out a credible challenge to the validity of the patent under Section 64(1)(f) of the Patents Act, establishing that the invention was obvious to a person skilled in the art. Consequently, the rejection of the interim injunction was upheld.
What This Means For Similar Cases
Obviousness Can Be Established Without Full Evidence
- Practitioners must now argue that even at the interim stage, a credible challenge to patent validity can be made using only the patent specifications and prior art documents - no expert testimony or lab data is mandatory.
- Where a genus patent discloses a broad class of compounds and a specific embodiment is merely a substitution of a preferred group, courts will treat it as obvious unless a technical surprise is demonstrated.
Common Inventors Raise the Obviousness Bar
- When the same inventors are involved in both the prior art and the challenged patent, courts may apply the "person in the know" standard, making it harder to claim inventiveness.
- This significantly impacts pharmaceutical patent litigation, where inventor overlap is common across patent families.
Interim Injunctions Require More Than Commercial Value
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Courts will not grant injunctions in patent cases where the patent is nearing expiry, even if the product is commercially valuable.
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Alternative remedies like account of profits or injunction to maintain accounts are now the preferred interim relief in such cases.
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Practitioners must assess patent expiry dates before filing injunction applications.
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Injunction applications must be filed promptly upon discovery of infringement - delay may render the remedy futile.
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Courts will not entertain appeals on interim orders if the patent will expire before the appeal is heard.
