Zydus Nivolumab Biosimilar – Injunction Overturned

ZYDUS LIFESCIENCES LIMITED vs E. R. SQUIBB AND SONS, LLC & ORS. | FAO(OS)(COMM) 120/2025 | Delhi High Court, Division Bench – 12 January 2026

In a landmark decision concerning biologics and biosimilars, the Delhi High Court set aside an interim injunction that had restrained Zydus Lifesciences from launching its biosimilar version of Nivolumab, a monoclonal antibody used in cancer treatment and marketed globally as Opdivo.

Background: The dispute arose from the patentee’s attempt to prevent the launch of Zydus’ biosimilar (ZRC-3276) on the basis that it was developed by referencing the patented biologic. The single judge had previously granted an injunction, effectively treating biosimilarity as indicative of patent infringement.

Key Findings: The Hon’ble Division Bench rejected this approach of treating biosimilarity as indicative of patent infringement, and explained a distinction that:

• Biosimilarity is a regulatory concept, assessed based on safety, efficacy, and quality.
• Patent infringement is a legal determination, requiring strict claim mapping against the patent claims.

The Court further noted:

• Absence of evidence demonstrating that Zydus’ product fell within the scope of the asserted claims of infringement.
• Possible non-fulfilment of certain claim limitations (e.g., binding affinity thresholds, which is a scientific parameter often in biologic patents to define how strongly a molecule (like a drug) binds to its target).
• The patent was nearing expiry, reducing the justification for interim relief.

Importantly, public interest considerations played a decisive role:

• The biosimilar was expected to be significantly more affordable for the general public (~70% cheaper).
• Denying access of these biosimilars would adversely impact patient affordability.

While vacating the previous injunction, the Hon’ble Court directed Zydus to maintain accounts of profits, thereby safeguarding the patentee’s potential monetary claims.

Significance: This ruling raises the evidentiary bar for patentees seeking interim injunctions in biologics cases, especially in quia timet actions (pre-launch disputes), and signals a more cautious approach toward restraining biosimilars.

Post-Expiry Revocation of Pharma Patents – Linagliptin

BOEHRINGER INGELHEIM PHARMA GMBH AND CO KG vs THE CONTROLLER OF PATENTS & ANR. | LPA 129/2025 | Delhi High Court, Division Bench – 24th February 2026

This case addressed whether a patent can still be challenged after its expiry, in the context of Linagliptin (a diabetes drug marketed as Trajenta).

Background & Procedural History:

• Indian Patent No. IN 243301 relating to the pharmaceutical product Linagliptin (used in diabetes treatment) was granted to Boehringer: Date of grant: 5 October 2012; Priority date: 21 August 2002.
• On 17 February 2022, Macleods Pharmaceuticals filed a revocation petition before the Delhi High Court under Section 64(1) of the Patents Act.
• Shortly thereafter Boehringer filed an infringement suit before the Himachal Pradesh High Court, alleging infringement of IN’301.
• Macleods, in its written statement, raised a defence of invalidity under Section 107(1).

Interlocutory Applications by Boehringer: Boehringer filed applications seeking dismissal of the revocation petition on two key grounds:

• Expiry of Patent (IA 7635/2024): Patent IN’301 expired on 18 August 2023 (efflux of time). Arguments raised: Revocation proceedings do not survive post-expiry; No revocation can be initiated or continued after expiry.
• Parallel Invalidity Defence (IA 46685/2024): Macleods had already raised invalidity under Section 107 in the infringement suit. It was submitted that a separate revocation petition under Section 64 was not maintainable after an invalidity has been claimed under Section 107 of the Patents Act.

Key Findings: The Court rejected both arguments and clarified that:

• Patent revocation operates retrospectively (ab initio). This meant that a revoked patent is treated as though it never existed.
• Expiry does not extinguish the right to challenge validity, particularly where the patent had commercial consequences.
• The Court further held a Section 107 invalidity defence does not bar a separate Section 64 revocation petition.
• However, courts must avoid duplicative adjudication, in line with the “one revocation” principle.

Significance: This ruling is particularly important for the pharmaceutical sector, where patent validity affects past damages and liabilities, and market strategies may have been shaped by the patent’s existence. It ensures that weak patents remain open to scrutiny, even post-expiry.

Novo Nordisk v Dr. Reddy’s Laboratories – Export Manufacturing of Semaglutide

Novo Nordisk v. Dr Reddys Laboratories Ltd. | 2026 SCC OnLine Del 898 | Delhi High Court – 9 March 2026

This case examined whether manufacturing a patented drug in India solely for export to countries without patent protection constitutes infringement.

Background & Factual Matrix:

• The dispute concerned Indian Patent No. 262697 (“Suit Patent”), titled: “Acylated GLP-1 Analogs Comprising Non-Proteogenic Amino Acid Residue”, covering Semaglutide.
• Key patent details: Filed: July 2007; Granted: September 2014; Expiry: 20 March 2026.
• Semaglutide is a globally significant drug used for diabetes and obesity, marketed under Ozempic, Wegovy, and Rybelsus.
• In October 2024, the Plaintiff discovered that certain Indian entities were importing and potentially manufacturing Semaglutide.
• Upon investigation the Defendant was found to be importing and exporting large quantities, indicating commercial activity (not merely for research purposes). Subsequently, a cease-and-desist notice was issued in May 2025.
• In response the Defendant filed a revocation petition challenging the validity of the Suit Patent. The Plaintiff initiated an infringement suit seeking an interim injunction under Order XXXIX Rules 1 & 2, CPC.

Undertaking Before the Court:

• During the hearing on 29 May 2025, the Defendant admitted manufacturing Semaglutide and gave an undertaking to not sell or market the drug in India and reserved the right to export to jurisdictions where no patent exists.
• The Court recorded the undertaking and thereafter did not restrain exports at that stage.
• On appeal, the Division Bench directed the Single Judge to decide the interim injunction application.

Court’s Analysis & Findings on Validity (Credible Challenge under Section 64):

• The Court first reiterated the “credible challenge” standard: A granted patent does not carry a presumption of validity (Section 13(4)); The relevant threshold at the interim stage is whether the defendant has raised a serious, non-frivolous challenge to validity. If such a challenge is established, interim injunction must ordinarily be refused, and the matter should proceed to trial.
• Priority Date and Treatment of Prior Art: The Plaintiff asserted a priority date of 18 March 2005. However, the European Opposition Division (EOD) had held that the relevant claim was not entitled to this priority; instead, the effective priority date was March 2006.
• Anticipation by Prior Publication (Section 64(1)(e)): The Court clarified that prior art need not explicitly name “Semaglutide”. It is sufficient if it discloses the essential features of the invention.

Final Decision: The Hon’ble Court held that no blanket injunction was granted and decided that the Defendant may continue manufacturing in India and only export to jurisdictions where no patent exists. However, this decision does not release the Defendant from their undertaking, which means that the Defendant was prohibited from selling their products in India.

“GLIMET” vs “GLYZET / GLYNET”

Laboratories Griffon Pvt Ltd And Anr vs Rajiv Mukul Proprietor Of Zee. | INTERIM APPLICATION NO. 3540 OF 2022 IN COMM IP SUIT NO. 213 OF 2022 | Bombay High Court – 13th January 2026

In a significant ruling reaffirming the heightened scrutiny applicable to pharmaceutical trademarks, the Hon’ble Bombay High Court granted an injunction in favour of the plaintiff’s mark “GLIMET”, restraining the defendants from using the deceptively similar marks “GLYZET” and “GLYNET.”

Factual Background: The dispute arose in the context of anti-diabetic pharmaceutical products, a therapeutic segment where precision in drug identification is critical. The plaintiff, proprietor of the mark “GLIMET,” had been using the mark in relation to medicines for the treatment of diabetes and had built a degree of recognition in the market. The defendants had earlier given undertakings to the Court agreeing not to use marks that were deceptively similar to the plaintiff’s mark. Despite such undertakings, the defendants adopted and continued to use the marks “GLYZET” and “GLYNET,” prompting the plaintiff to initiate contempt and infringement proceedings.

Court’s Analysis: The Court undertook a phonetic, visual, and structural comparison of the marks and observed that:

• All marks shared the common prefix “GLY”, which is commonly associated with glucose-related medications.
• The suffixes “MET,” “ZET,” and “NET” were found to be phonetically similar, especially in the context of prescriptions, where handwriting or verbal communication may be unclear.
• The overall structure and cadence of the marks created a real likelihood of confusion, particularly among patients, pharmacists, and medical practitioners.

The Court placed strong reliance on established jurisprudence (including principles from Cadila Healthcare Ltd. v. Cadila Pharmaceuticals Ltd.) which mandates a stricter test in pharmaceutical trademark disputes due to the direct impact on public health.

Aggravating Factors: What made this case particularly serious was the conduct of the defendants:

• Deliberate breach of prior undertakings given to the Court;
• Evidence suggesting dishonest adoption rather than coincidental similarity;
• Continued use of the impugned marks despite being on notice.

Relief and Penalties: In light of these factors, the Hon’ble Court:

• Granted a permanent injunction restraining use of the impugned marks;
• Imposed exemplary costs of ₹50 lakhs, signalling strong judicial disapproval;
• Directed initiation of perjury proceedings, highlighting the seriousness of misleading the Court.

Legal Significance: This decision reinforces several key principles:

• Pharmaceutical trademark disputes are subject to a public interest overlay, where even minimal confusion is unacceptable;
• Courts are willing to impose punitive costs and sanctions where parties act in bad faith;
• Prior undertakings, once breached, significantly weaken a defendant’s case and invite stricter scrutiny.