Patents

Genus, Meet Species: Court Weighs Novo Nordisk’s Semaglutide Patent

Gaurav Mishra · · 6 min read

A split visual showing two intertwined molecular chain diagrams, one suggesting a broader "genus" structure and the other a narrower "species" compound, connected by a single highlighted amino acid link, evoking the scientific heart of the dispute without depicting any real drug packaging. Featured image for: Genus, Meet Species: Court Weighs Novo Nordisk’s Semaglutide Patent

Summary

Novo Nordisk A/S sued Dr Reddy's Laboratories Limited (Dr Reddy's) before the Delhi High Court, alleging that Dr Reddy's import and export of Semaglutide, the active ingredient in its anti-diabetic drugs Wegovy and Rybelsus, infringed its Indian Semaglutide patent. A Single Judge declined to grant an interim injunction, holding that Dr Reddy's had raised a credible challenge to the patent's validity, and Novo Nordisk appealed to a Division Bench with barely two months left on the patent's term. The Division Bench dismissed the appeal, holding that Semaglutide was rendered obvious by Novo Nordisk's own earlier genus patent under Section 64(1)(f) of the Patents Act, 1970, even while disagreeing with the Single Judge's reliance on Section 64(1)(a). The ruling matters because it sharpens the distinction between anticipation by prior claiming and obviousness in genus-species patent disputes, and reinforces the "person in the know" standard for evaluating obviousness when the same inventors sit behind both patents.

Background

A patent with barely two months left to run reached India’s premier commercial court on appeal, prompting the bench to question whether the exercise was worth judicial time at all before it turned to the substance of the dispute over Novo Nordisk’s Semaglutide patent.

The fight was between Novo Nordisk A/S (“Novo Nordisk”), the pharmaceutical major behind the anti-diabetic drugs Wegovy and Rybelsus, and Dr Reddy’s Laboratories Limited and another (“Dr Reddy’s”), the Indian generics manufacturer. Novo Nordisk holds Indian Patent 262697 (“suit patent” or “IN’697”), granted for an invention titled “Acylated GLP-1 Analogs Comprising Non-Proteogenic Amino Acid Residue,” with a priority date of 18 March 2005. Semaglutide, marketed as Wegovy and Rybelsus, is claimed under Claim 23 of IN’697. Novo Nordisk learned in December 2024 that Dr Reddy’s was importing and exporting Semaglutide, issued a cease-and-desist notice on 5 May 2025, and, getting no response, sued before the Intellectual Property Division of the Delhi High Court on 26 May 2025, securing a voluntary undertaking from Dr Reddy’s not to sell Semaglutide in India pending trial. Dr Reddy’s did not dispute the import activity but invoked Section 107(1) of the Patents Act, 1970 (“Patents Act”), challenging validity under Section 64(1). On 2 December 2025, a Single Judge declined an interim injunction, holding that Dr Reddy’s had raised a credible challenge to validity. Novo Nordisk appealed to a Division Bench, which reserved judgment on 19 January 2026 and ruled on 9 March 2026, days before the suit patent’s expiry on 20 March 2026.

Issues

    • Whether Dr Reddy’s raised a credible challenge to the validity of IN’697 under Section 64(1)(a), on the ground of anticipation by prior claiming in Novo Nordisk’s own earlier Genus Patent, IN’964.
    • Whether any credible challenge was more properly founded in Section 64(1)(e), anticipation by prior publication, or Section 64(1)(f), obviousness and lack of inventive step.
    • Whether a person skilled in the art, or a “person in the know” given inventors common to both patents, would be led from IN’964’s teachings to the Semaglutide compound.
    • Whether the Division Bench, confined to the Wander standard for appeals against discretionary interlocutory orders, should interfere with the Single Judge’s refusal of an interim injunction.

Novo Nordisk’s Arguments

    • Contended that IN’964 neither validly claimed nor enabled Semaglutide, since only Claims 18 and 21 of IN’964 specifically claimed compounds, and neither was Semaglutide itself.
    • Argued that the exemplified Compound 61 under Claim 21 of IN’964 differed from Semaglutide only by a single amino acid substitution, Aib for Ala at position 8, which it framed as pharmacologically significant rather than trivial.
    • Relied on its own comparison and an expert affidavit, arguing that non-proteogenic amino acid substitutions carry distinct immunogenicity risks in chronically administered drugs.
    • Argued that, under the Wander standard, the Division Bench should not disturb the Single Judge’s discretionary order absent an arbitrary, capricious, or perverse exercise of discretion.

Dr Reddy’s Arguments

    • Admitted importing and exporting Semaglutide but invoked Section 107(1) as a defence to infringement, challenging the suit patent’s validity.
    • Argued, relying on the genus-species principle applied in Novartis AG v. Union of India (2013) 6 SCC 1, that Novo Nordisk could not re-appropriate through IN’697 subject matter already claimed in its own earlier Genus Patent, IN’964.
    • Pointed to Claim 1 and dependent Claim 16 of IN’964, which disclosed Aib as the preferred substitution at position 8, arguing this taught a person skilled in the art directly to Semaglutide.
    • Relied on Novo Nordisk’s own pleadings and foreign filings admitting that Semaglutide was the sole commercial product resulting from both IN’964 and IN’697.

Court’s Analysis

The Limits of Appellate Interference

The court observed that an appeal against a discretionary interlocutory order is an appeal on principle, not a fresh trial, and that the Division Bench could interfere only if the Single Judge’s discretion had been exercised arbitrarily, capriciously, or perversely, or in disregard of settled principles governing interim injunctions. The court noted that Wander Ltd. v. Antox (India) Pvt. Ltd. (1990 Supp SCC 727), reaffirmed in Pernod Ricard v. Karanveer Singh Chhabra (2025 SCC OnLine SC 1701), confined the Bench within these limits, and that it would not undertake a fresh assessment of Novo Nordisk’s claim for injunction.

Anticipation Versus Obviousness: Drawing the Line

The court held that Section 64(1)(a) applies only where the invention, so far as claimed in the suit patent, was claimed in an earlier valid claim of another granted patent, requiring strict claim-to-claim congruence rather than a broader comparison of disclosures. The court reasoned that the person skilled in the art plays no role under Section 64(1)(a), becoming relevant only under Section 64(1)(e) and, more directly, Section 64(1)(f). The court found that the Single Judge, while reaching the correct outcome, had conflated anticipation by prior claiming with obviousness, and that her reasoning in fact supported a credible Semaglutide patent challenge under Section 64(1)(f) rather than Section 64(1)(a).

From Genus to Species: Reading IN’964 Against the Suit Patent

The court observed that Novo Nordisk’s own rejoinder had identified three features distinguishing Semaglutide from prior art, and that two of those three were already present in Compound 61, exemplified under Claim 21 of the Genus Patent. The court noted that the sole remaining difference was the substitution of Aib for Ala at the eighth position, and that Claim 1 of IN’964, read with dependent Claim 16, expressly disclosed Aib as the preferred substitution there. The court stated that this combination of teachings sufficed to guide a skilled person to Semaglutide without undue experimentation, undercutting the presumption of validity attached to Novo Nordisk’s Semaglutide patent.

The “Person in the Know” and the Aib Substitution

The court further observed that five inventors were common to both the Genus Patent and the suit patent, a fact that, per AstraZeneca AB v. Intas Pharmaceuticals Ltd. (2021 SCC OnLine Del 3746), shifted the inquiry from an anonymous person skilled in the art to a “person in the know.” The court opined that, viewed through this lens, the path from IN’964’s teachings to Semaglutide was even clearer, since the same inventive minds stood behind both patents. The court also acknowledged, citing the five-step obviousness framework from F. Hoffmann-La Roche Ltd. v. Cipla Ltd. ((2016) 65 PTC 1 (DB)), that a full inquisitorial analysis suited trial better than the interlocutory stage, confining itself to a prima facie assessment consistent with the credible challenge standard from the earlier F. Hoffmann-La Roche Ltd. v. Cipla Ltd. (159 (2009) DLT 243 (DB)) decision.

Findings

In view of the observations and the arguments presented by both the parties, the Delhi High Court held that:

    • Dr Reddy’s had not made out a credible challenge to the validity of the suit patent under Section 64(1)(a), since that provision required claim-to-claim congruence that was absent on the facts.
    • Dr Reddy’s had made out a credible challenge to the validity of the suit patent under Section 64(1)(e) and, in particular, Section 64(1)(f), on the ground that Semaglutide was obvious over the teachings of the Genus Patent, IN’964.
    • The Single Judge’s refusal of an interim injunction did not reflect an arbitrary, capricious, or perverse exercise of discretion, and warranted no interference.
    • The appeal was dismissed, and the undertaking given by Dr Reddy’s on 29 May 2025 not to sell Semaglutide in India was left undisturbed pending trial.
    • The observations recorded were prima facie in nature and would not bind the Single Judge’s final adjudication of the suit on merits.

Case Citation: Novo Nordisk A/S v. Dr Reddy’s Laboratories Limited & Anr., FAO(OS) (COMM) 204/2025 & CM APPL. 78607/2025, Delhi High Court, decided on 9 March 2026. Available at https://indiankanoon.org/doc/144556936/.

Authored by Gaurav Mishra, Patent Attorney, BananaIP Counsels

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