The Delhi High Court has issued an interim injunction preventing Zydus Lifesciences Limited from launching its biosimilar version of the cancer immunotherapy drug Nivolumab, marking a significant victory for patent holder E.R. Squibb and Sons LLC in protecting intellectual property rights for biologics in India.
Justice Mini Pushkarna granted the relief in favor of Squibb and Sons, restraining Zydus from manufacturing, selling, importing, exporting, or dealing in any biologic similar to Nivolumab, which is marketed under the brand name Opdivo. The decision stems from a patent infringement suit concerning Indian Patent No. IN 340060, titled "Human Monoclonal Antibodies to Programmed Death 1 (PD-1) for use in treating Cancer."
Patent Protection and Biosimilar Development
The suit patent, with a 20-year term starting from May 2, 2006, and expiring on May 2, 2026, covers the monoclonal antibody Nivolumab (also known as 5C4), which binds to the PD-1 receptor on T-cells to modulate immune responses against cancer cells. The patent was granted in India on July 1, 2020, after rejection of four pre-grant oppositions.
Squibb and Sons filed the lawsuit after discovering that Zydus had registered clinical trials for its biosimilar ZRC-3276, specifically identifying Opdivo as the reference product. The plaintiffs became aware in April 2022 that Zydus had sought regulatory approval for clinical trials, and later learned in April 2024 that the company had applied for marketing authorization.
Court's Analysis of Infringement Claims
The court found that Nivolumab was clearly claimed in Claims 1, 3, and 7 of the suit patent, which are defined by specific amino acid sequences in the CDR regions and variable chains. Since Zydus was developing a biosimilar using the plaintiffs' product as a reference, the court determined it was prima facie covered by the scope of the claims.
Justice Pushkarna noted that "any infringing products manufactured, offered for sale or sold, etc., during the life or term of the patent, do not gain credibility and thus, their manufacture and stockpiling during the said period, would also amount to infringement."
Prior Art Challenge Rejected
Zydus attempted to challenge the patent's validity by citing prior art documents including WO 2001/014557, WO 2002/079499, and EP 1537878 B1. However, the court found that these documents did not disclose the specific amino acid sequences claimed in the suit patent. The court relied on the Guidelines for Examination of Biotechnology Applications for Patent, 2013, which state that unless prior art matches the claimed sequence exactly, it cannot be deemed anticipatory.
The court also dismissed Zydus's reliance on an Opposition Board Recommendation (OBR) dated January 31, 2023, which had opined that the suit patent lacked novelty and inventive step. The court noted the recommendatory nature of such opinions and referenced that the OBR was subsequently set aside by the High Court of Madras.
Global Patent Validation
The court emphasized the patent's international standing, noting that "the patent in question is valid in fifty countries across the world. The validity of the patent was challenged in thirty countries and has successfully been sustained." The court also observed that the plaintiffs were granted the suit patent after fourteen years, thereby shortening their limited monopoly period.
Interim Relief and Disclosure Requirements
The court granted comprehensive interim relief, continuing the injunction against Zydus from launching or commercially exploiting its biosimilar product ZRC-3276 without court approval until the patent expires or final adjudication of the suit. Additionally, the court directed Zydus to file an affidavit within four weeks disclosing the quantity of any manufactured biosimilar product of Nivolumab.
Justice Pushkarna stated that "the defendant will be free to launch its product" after the patent expires in May 2026, acknowledging the temporary nature of the restraint while protecting the patent holder's rights during the remaining patent term.
Implications for Biosimilar Industry
This judgment reinforces the jurisprudence on quia timet actions in patent infringement suits, particularly in the biopharmaceutical context. The decision clarifies that apprehension of infringement, if supported by credible evidence, can sustain an injunction even before actual product launch. The case also reaffirms that prior art must disclose specific elements of claimed inventions, such as amino acid sequences in biologics, for credible challenges to novelty or inventive step.
