Summary
The Delhi High Court has restrained Zydus from commercially launching a biosimilar to Nivolumab, the anti-PD-1 monoclonal antibody patented by Squibb under IN 340060. The injunction, granted as interim relief in a quia timet action, underscores the Court’s stance on biosimilar patent enforcement and affirms that public interest cannot override statutory IP rights. The Court found that ZRC-3276 shares key features with Nivolumab and held that Zydus’s invalidity and non-infringement defences lacked merit, while also rejecting reliance on the non-binding OBR.
In E.R. Squibb and Sons LLC & Ors. v. Zydus Lifesciences Limited, the Delhi High Court granted an interim injunction restraining Zydus from manufacturing, selling, importing, exporting, or dealing with any biologic similar to Nivolumab until the expiry of Squibb’s Indian patent No. IN 340060 on May 6, 2026. The injunction was granted in response to a quia timet action initiated by Squibb, citing an imminent threat of infringement against its anti-PD-1 monoclonal antibody, Nivolumab.
Background
E.R. Squibb and Sons LLC (“Squibb”) holds Indian Patent IN 340060, which claims an anti-PD-1 monoclonal antibody that has been assigned the International Non-proprietary Name (INN) Nivolumab by WHO. Nivolumab functions by inhibiting PD-1, a receptor on T-cells that suppresses immune responses. By blocking PD-1, Nivolumab restores T-cell activity, enabling immune cells to recognize and eliminate cancer cells. The antibody’s specificity to PD-1 is determined by six unique Complementarity Determining Regions (CDRs), which are critical to its therapeutic efficacy. Nivolumab is marketed globally under the brand name Opdivo® and is imported into India as Opdyta®.
In 2024, Squibb obtained information that Zydus was preparing for a commercial launch of its biosimilar candidate, ZRC-3276, using Nivolumab (Opdivo®) as the reference product. In response, Squibb initiated a quia timet suit along with an application for interim relief. On May 8, 2024, the Court granted an interim injunction, restraining Zydus from launching or marketing ZRC-3276, pending the outcome of the trial.
Key Arguments by Squibb
Squibb claimed that it holds a valid and enforceable patent for Nivolumab and alleged that ZRC-3276 infringes the patent by incorporating the same antibody sequences claimed therein.
Squibb also argued that Zydus failed to raise a credible challenge to the validity of the suit patent. They contended that Zydus’s reliance on prior art EP1537878 B1 was insufficient, as it did not disclose the specific amino acid sequences in the suit patent.
Additionally, Squibb challenged Zydus’s reliance on the Opposition Board Report (OBR), which had recommended that the suit patent lacked novelty. They claimed that OBR is merely recommendatory and non-binding and pointed out that the report’s validity is under judicial review before the Madras High Court, which has remanded the matter for reconsideration.
Squibb also argued that permitting Zydus to commercialize its biosimilar prior to the patent’s expiry would cause irreparable harm to its statutory rights, market share, and reputation. In contrast, Zydus would face no significant prejudice from being restrained, particularly since the patent is set to expire within a year.
Arguments by Zydus
Zydus challenged the validity of the suit patent on grounds of novelty and inventive step, citing various prior art including WO 2001/014557, WO 2002/079499 and WO 2004/004771. They also asserted that the OBR’s findings supported their claim of invalidity.
Zydus further argued that the antibody in question is a natural product with no substantial human intervention and is thus non-patentable under Indian patent law. Additionally, Zydus denied infringing the suit patent, asserting that their biosimilar, ZRC-3276, has a distinct binding profile, interacting with multiple CD28 family receptors, unlike Nivolumab, which binds exclusively or predominantly to the PD-1 receptor.
Zydus maintained that biosimilarity alone does not amount to infringement, which must be established through precise claim-to-product mapping. It challenged Squibb’s reliance on the International Nonproprietary Name (INN) “Nivolumab” for sequence comparison, arguing that the INN designation is non-exclusive and, under WHO guidelines, may encompass antibodies with broader binding characteristics that fall outside the scope of the patent claims.
Additionally, Zydus invoked Section 107A of the Patents Act (the Bolar exemption), stating that its activities were limited to clinical trials for regulatory approval, and thus constituted permissible “experimental use,” rather than infringement. They argued that Squibb was aware of these activities as early as April 2022 but delayed initiating legal proceedings, which weakened the claim of urgency and suggested an attempt to unjustifiably prolong its monopoly over Nivolumab.
On the issue of balance of convenience, Zydus submitted that it had made substantial investments in regulatory approvals and clinical development, and that an injunction would impede public access to affordable treatment. They argued that with the patent expiring in less than a year, the public interest and proportionality weighed against granting interim relief.
Observations by the Court
The Court rejected Zydus’s contention of delay in filing the suit, agreeing with Squibb that the cause of action arose only in 2024 upon learning of Zydus’s plans to commercially launch its biosimilar.
The Court observed that ZRC-3276 shares the same CDRs and amino acid sequences as Nivolumab and binds specifically to PD-1, thereby establishing a prima facie case of infringement. Considering the quia timet nature of the suit and the fact that the product had not yet been commercially launched due to an interim injunction, the Court found that precise claim-to-product mapping was not feasible. It clarified that in such cases, claim mapping is required only “to the extent possible” and need not be strictly applied.
On the issue of validity, the Court held that Zydus failed to establish a credible challenge. The cited prior art documents did not disclose the specific amino acid sequences claimed in the suit patent, and thus could not anticipate the claimed invention. It also rejected Zydus’s argument that Nivolumab was a natural product, since the claimed invention involved biotechnological processes and human intervention.
The Court weighed on the fact that patent had been granted in more than fifty jurisdictions, including India, the US and the EU, and had not been revoked or invalidated anywhere. It also dismissed Zydus’s reliance on the OBR, noting its non-binding status and the pending judicial review before the Madras High Court.
While recognizing the public interest in biosimilars, the Court concluded that public interest does not justify undermining statutory IP rights. The Court observed that post-patent expiry, Zydus could lawfully launch its product; meanwhile, granting interim protection to Squibb maintained the integrity of the patent system. It clarified that any product manufactured, sold, or stockpiled during the life of the patent, without the patentee’s authorization, amounts to infringement.
Finally, the Court found that the balance of convenience favoured Squibb. Granting an injunction would protect its statutory patent rights, whereas Zydus would not suffer irreparable harm, as the patent is set to expire in May 2026.
Conclusion
The Delhi High Court granted an interim injunction restraining Zydus from manufacturing, using, selling, or dealing with any biosimilar of Nivolumab during the pendency of the suit. Zydus was also barred from launching any product manufactured during the patent term, even after its expiry. It directed Zydus to file an affidavit within four weeks disclosing the quantity of biosimilar already manufactured. The Court also clarified that these findings are prima facie and will not affect the final outcome of the trial.
Citation: E. R. Squibb And Sons, Llc & Ors vs Zydus Lifesciences Limited, (H. C. Delhi 18 July, 2025), CS(COMM) 376/2024 & I.A. 10533/2024
Available at https://indiankanoon.org/doc/108686314/
Article Review: Vasundhara Paliwal
Accessibility Review: Gaurav Mishra
