A patent with five months of life left is a peculiar thing to litigate. Whatever the court eventually decides about validity or infringement, the monopoly will be gone before the suit is anywhere near trial. The interim application is not a holding measure ahead of the real decision. It is the real decision, arriving in the costume of a provisional one.

The Delhi High Court's Division Bench said as much, in substance, when it lifted the injunction restraining Zydus from marketing its Nivolumab biosimilar.

What Was at Stake

Nivolumab is a monoclonal antibody used in cancer immunotherapy, sold as Opdivo internationally and Opdyta in India. The Indian patent, IN 340060, is held by E.R. Squibb & Sons, part of Bristol Myers Squibb.

Zydus developed ZRC 3276, a biosimilar. In July 2025 a Single Judge restrained its marketing on the basis of patent infringement. Zydus appealed, and on 12 January 2026 the Division Bench of Justices C. Hari Shankar and Om Prakash Shukla vacated that injunction — allowing the biosimilar to be sold until the patent expired in May 2026.

The patent has since expired. Which means the appeal, not the suit, settled what actually happened in the market.

The Analytical Failure

The Division Bench's first ground was technical and, for patent litigators, the more consequential of the two.

Interim relief had been granted without a proper product-to-claim infringement analysis. That phrase describes an exercise that sounds obvious and is frequently skipped: taking the claims of the asserted patent, element by element, and mapping the defendant's product onto them to see whether each integer is present.

In small-molecule litigation this is often straightforward — the molecule either is or is not the claimed compound. Biologics are not like that. A biosimilar is not a copy; it is a separately manufactured protein demonstrated to be highly similar to the reference product for regulatory purposes. Regulatory similarity is a different question from claim-by-claim correspondence, and the Bench's point was that establishing the first does not discharge the burden of showing the second.

A patentee asserting a biologic patent against a biosimilar has to do the mapping. Pointing at the regulatory pathway the defendant used is not a substitute.

The Weight Given to Public Interest

The second ground has drawn more commentary and is the harder one to apply.

The Bench treated public interest as not merely relevant but pre-eminent on these facts. The product was an affordable biosimilar of a life-saving cancer therapy. The patent was months from expiry. Restraining entry in that window would have kept prices high for a short and fixed period, at real cost to patients, in exchange for protecting a monopoly that was about to lapse regardless.

Framed that way the conclusion is difficult to resist. It also carries a consequence patentees will not welcome: the closer a pharmaceutical patent is to expiry, the weaker its claim to interim protection becomes — precisely when the commercial temptation for a generic or biosimilar entrant to launch is greatest.

There is something uncomfortable in that. A patent's final months are still the patentee's months. A rule that makes them functionally unenforceable rewards the entrant who times its launch to arrive after the injunction calculus has tipped. The Bench did not endorse that outcome, and the accounting condition it imposed is designed to blunt it. But the incentive is now visible in the case law, and it will be read.

The Condition That Preserves the Claim

Vacating the injunction was not an absolution. Zydus was directed to maintain and file audited accounts of revenue generated from sales of the biosimilar during the subsistence of the suit patent.

This is the mechanism that keeps the patentee's remedy alive. If Squibb ultimately establishes infringement and validity, the audited record converts into the basis for a damages or account-of-profits claim covering the period the injunction was lifted. The patentee loses exclusivity and retains a monetary claim.

Whether that is adequate compensation depends on your view of the value of exclusivity. For a patent in its final months, with the market about to open anyway, a monetary remedy is a closer substitute than it would be for one with a decade to run — which is part of why the balance tipped as it did.

The Takeaway

For patentees, two working points. Interim relief against a biosimilar now requires claim mapping done properly and in advance; a case built on regulatory similarity will not carry an injunction. And enforcement strategy has to account for the remaining term, because a suit filed late in a patent's life is one where the interim stage is likely to be dispositive in commercial terms whatever the eventual judgment says.

For entrants, the accounting direction is the thing to weigh. Launching under a vacated injunction is not a free run — it is a run conducted under a court-supervised record that a patentee can convert into a claim later. Clearing the way before launch remains the safer course, and the courts have not stopped saying so.

The wider signal is about how Indian courts are now handling pharmaceutical interim relief. Public interest has moved from a factor recited in the balance-of-convenience analysis to one capable of carrying the result on its own where the drug is essential and the patent is nearly spent. That is a meaningful shift, and it is not confined to oncology.