The patent war between Bristol Myers Squibb (BMS) and Zydus on the Nivolumab patent held by BMS took a new turn when an Appellate Division Bench of the High Court of Delhi overturned the Single Judge order [July 2025] for the grant of a preliminary injunction that put the brakes on the Indian launch of Nivolumab ZRC-3276 by Zydus. In a detailed analysis of the judgment of the Single Judge, the Appellate Court in Zydus Lifesciences Limited vs Bristol Myers Squibb [FAO(OS) (COMM) 120/2025, CM APPL. 44383/2025, CM APPL. 44386/2025 & CM APPL. 44388/2025] was of the considered opinion that the interests of justice would be adequately subserved if the impugned judgment is modified by vacating the injunction granted by the impugned judgment and requiring the appellant, instead, to file, with the Registry of the Court and an advance copy to the respondent, audited accounts of the amounts earned by the appellant by sale of the allegedly infringing product, till the expiry of the suit patent.
The appellate Court noted that, as only a period of hardly four months remained until the suit patent expires, this arrangement would protect the interests of both sides. According to the Court, this would also ensure that the availability of the appellant’s product to the public, who may be in need of it, was not restrained any further. The Appellate Court found that the Single Judge erred in finding that ZRC-3276 was likely to have an infringing amino acid sequence merely because it was a biosimilar to Nivolumab, as there was no evidence of the actual sequence of ZRC-3276. The Court clearly distinguished between the bio-similarity assessment by the regulatory authority based on comparable safety, efficacy, quality, etc., and patent infringement analysis based on the presence of an amino acid sequence in the infringing product. The Appellate Court thus separated the regulatory issues from issues of patent infringement. The Appellate Court agreed with Zydus’ argument that there was evidence that neither ZRC-3276 nor Opdivo® satisfied the protein-binding affinity limitation of the claims of the suit patent.
Appellant’s Case
Public Interest Plea
At the onset, the appellant submitted that their product ZRC 3276 was an anticancer drug, and it was essential for the treatment of a wide variety of life-threatening carcinomas. The appellant submitted that making lower-cost, life-saving drugs available was in the public interest. According to the appellant, the treatment using the appellant’s product would be 70% cheaper than treatment using the respondent’s patented drug 5C4. The appellant submitted that the Supreme Court has, in its decisions in Ramnik Lal Bhutta vs State of Maharashtra1 and Raunaq International vs I.V.R. Construction Ltd, held that, while considering pleas for injunction or stay, public interest is also a consideration to be borne in mind, apart from the classical troika of a prima facie case, balance of convenience and irreparable loss.
Patent vs Biologic Product
The appellant submitted that, admittedly, no mapping of the appellant’s product ZRC 3276 onto the claims in the respondent’s suit patent was done at any stage. The appellant argued that the mere manufacture of a biosimilar of Nivolumab could never amount to patent infringement or an admission thereof, since the test for patent infringement is a claim-to-product comparison, whereas the test for assessing a biosimilar is a product-to-product comparison. The appellant further submitted that their case of noninfringement was premised on the fact that the appellant’s biosimilar was not ‘isolated’ and ‘does not bind specifically to PD-1’ but also binds to other members of the CD-28 family, 3276, mapped onto the suit patent. The appellant submitted that there was evidence that neither ZRC-3276 nor Opdivo® satisfied the protein-binding affinity limitation of the claims.
Court’s Analysis and Findings
On Public Interest
On the issue of considering public interest while deciding an injunction at the preliminary stage, the appellate Court observed that “we have no doubt about the mere fact that the injuncted product is a lifesaving drug is no absolute armour against an injunction. The appeal court noted that products which infringe the patents of others cannot be permitted to circulate in the market”.
The appellate Court further observed that “keeping in mind the pre-eminent consideration of public interest, we are of the opinion that the interests of justice would adequately have been subserved if the appellant were to be directed to maintain and file, with this Court, periodical accounts of the amounts earned through sale of the appellant’s product, so as to secure the respondent in the event of its succeeding in the suit.”
On Claim Mapping
The Appellate Court examined the claim mapping to ensure the iota of infringement by an alleged biosimilar product marketed by Zydus. The Court noted that Rule 3(A)(ix) of the High Court of Delhi Rules Governing Patent Suits, 2022, specifically requires product-to-claim mapping as one of the necessary ingredients of a patent infringement suit. The court disagreed with the impugned judgment, which held that the words “to the extent possible”, in Rule 3A, may, in a quia timet action, justify doing away with the requirement of product-to-claim mapping altogether. According to the Court, this case, however, was peculiar, as there was admittedly no mapping of the appellant’s product ZRC 3276 onto the claims in the respondent’s suit patent at any stage. Injunction was, therefore, granted without any product-to-claim mapping.
On Product-to-Product Comparison
The learned Single Judge had held that as ZRC 3276 and 5C4 were both revealed, on testing, to bind comparably to CD 28 proteins other than PD-1, ZRC 15. The Appellate Court observed that the approach of the impugned judgment to proceed based on product-to-product mapping was fundamentally flawed, as it would envisage product-to-product mapping. In contrast, patent infringement must be assessed based on product-to-claim mapping. Further, there was no justification for the grounds that led the respondents to believe that the biosimilar employed by the appellant was the same as the suit patent, since the suit patent was not for Nivolumab but for an ‘isolated monoclonal antibody’ that ‘binds specifically to PD1’. The Appellate Court also agreed with the appellant that there was evidence that neither ZRC-3276 nor Opdivo® satisfied the protein-binding affinity limitation of the claims.
On the Meaning of ‘Product’ under Section 48
Citing the importance of identifying the infringing product under Section 48, the Appellate Court questioned the findings of the Single Judge that even in the absence of product-to-claim mapping, the fact that the appellant’s product was in fact the product claimed in the suit patent stood prima facie established through other material. In the claim mapping conducted by the respondents, the 6 CDR sequences were mapped to the INN Nivolumab; however, the features ‘isolated’ and ‘binding specifically to PD-1’ were not mapped. This incomplete mapping, according to the Court, was a glaring error since the appellant’s case of non-infringement was premised on the fact that the appellant’s bio-similar was not ‘isolated’ and did not ‘bind specifically to PD-1′ but also to other members of the CD-28 family, 3276 mapped onto the suit patent. According to the Court, this led to a position that neither ZRC 3276 nor 5C4 would actually map onto the granted claim in the suit patent. The Court found that the first instance judge was wrong to find that ZRC-3276 was likely to have an infringing amino acid sequence merely because it was a biosimilar to Nivolumab when there was no evidence of the actual sequence of ZRC-3276.
Decision of the Appellate Court
The Appellate Court modified the Single Judge’s order by vacating the order for granting the injunction. The Court directed Zydus to provide an account of profits for sales of the allegedly infringing product until the expiry of the patent in suit.
Conclusion and Takeaways
This appeal resolved issues of fundamental importance, not merely as legal principles relating to the patent regime, but also of vital public interest. This case once again highlighted that public interest may play a role in deciding injunction suits. Still, the mere fact that the injuncted product is a life-saving drug is no absolute armour against an injunction. The appellate Court clearly stated that products that infringe others’ patents cannot be permitted to circulate in the market. The Court reiterated that intellectual property rights are entitled to protection. The court vacated the injunction on the ground that accurate claim mapping to assess the possibility of infringement by an alleged biosimilar product was essential to seek even a preliminary injunction. This ruling highlighted the importance of claim mapping as a tool for establishing infringement, even at the preliminary injunction stage. The case also ruled that the regulatory issues are distinct from issues of determining patent infringement.
Author: DPS Parmar (Special Counsel)