含羞草社区

含羞草社区 pharmaceutical landscape is witnessing a landmark shift as biosimilar manufacturers race to offer alternatives to life-saving treatments.

Two Delhi High Court cases have produced a body of jurisprudence on the intersection of biologic science and patent enforcement: F Hoffmann-La Roche Ag & Anr v Zydus Lifesciences Limited (Pertuzumab); and ER Squibb & Sons LLC v Zydus Lifesciences Limited (Nivolumab).

Pertuzumab biosimilar injunction and discover

Roche commenced a quia timet action before Delhi High Court for infringement of two patents for Pertuzumab, a monoclonal antibody that is used to inhibit tumour growth. The court initially declined injunctive relief, noting an absence of any claim mapping to demonstrate that Zydus’ product would infringe the suit patents.

Subsequently, an interim injunction was granted on grounds of procedural fairness, when Roche argued that Zydus withheld its Central Drugs Standard Control Organisation (CDSCO) approval from the court records. However, this injunction was ultimately set aside through successive appellate proceedings, leaving no interim restraint in Roche’s favour.

The most significant development arose in the process discovery context. The court held that Roche had not demonstrated that Zydus’ product was identical to the product directly obtained by the patented process, particularly since Roche had not done any analytical characterisation of Sigrima after its market launch. This is a mandatory precondition under section 104A of the Patents Act, 1970.

Nivolumab injunction vacated, mapping required

In the Nivolumab litigation, a single judge initially granted an interim injunction to restrain Zydus from dealing in any biosimilar of Nivolumab, accepting an indirect claim mapping approach of mapping the suit patent to the Nivolumab reference standard rather than to Zydus’ actual product.

However, a division bench of the court found it “peculiar” that an injunction had been granted without any product-to-claim mapping, and vacated the injunction. The bench instead directed audited accounts of sales to balance public access with patent protection.

Before the Supreme Court, it was recorded that the patentees could perform direct product-to-claim mapping using samples to be supplied by Zydus, with liberty to approach the division bench thereafter.

Biosimilar disputes: Mapping, discovery and fairness

Claim mapping. These litigations together establish the indispensability of claim mapping in biosimilar patent disputes. Product-to-product comparisons between a biosimilar and a reference product do not constitute the legal test for infringement. Claim-to-product mapping is the required inquiry, as rights under section 48 attach to “that product” as defined by the claims.

Process discovery and section 104A. In Pertuzumab, the court held that regulatory “biosimilarity” – similarity in quality, safety and efficacy – does not satisfy the patent law threshold of “identity” under section 104A, nor does it justify any inference that a patented manufacturing process has been used by a defendant. In the context of process patent disclosure, section 104A, as a special statute, prevails over broader discovery provisions under the Civil Procedure Code.

Regulatory transparency. Courts expect parties to disclose material regulatory developments during proceedings.

Public interest. Public interest seems relevant in injunction analysis for life-saving medicines but is not an absolute armour against injunction where clear infringement is shown. Where infringement remains unestablished, courts may prefer audited account remedies rather than removing a drug from market.

Expert evidence. Given the technical complexities, Indian courts have mooted the appointment of independent scientific advisers and the use of “hot tubbing” to assist courts in understanding the science behind the drug.

As these litigations continue to evolve through the appellate and trial proceedings, their outcomes are poised to shape the contours of biologic patent enforcement in India for many, many years to come.

Swati Sharma is a partner (head, intellectual property) and Gitika Suri is director, patents, at Cyril Amarchand Mangaldas