India’s generic drugmakers are set to gain a stronger shield against damages claims tied to expired patents after the Delhi High Court ruled that a patent that has completed its 20-year term can still be cancelled if it remains under legal challenge.
The court, in its 24 February ruling, clarified that a patent owner can still seek damages from a generic drugmaker for infringement that happened while the patent was valid. However, the patent can be cancelled even after expiry if it is still under challenge. If the expired patent is later revoked, the damages claim will not survive because the patent will be treated as if it never existed.
The dispute involves German drugmaker Boehringer Ingelheim and Macleods Pharmaceuticals, which are fighting over a patent for the diabetes drug Linagliptin. Macleods challenged the patent’s validity in the Delhi High Court, while Boehringer filed an infringement suit in the Himachal Pradesh High Court, seeking an injunction and damages.
The German drugmaker argued that the cancellation case should be stopped because the patent had already expired and as its validity was already being questioned in another lawsuit. The court disagreed and rejected the plea. It said that even if a patent has expired, it can be cancelled.
Importantly, the court observed that there is no clear Indian precedent directly dealing with whether a revocation petition can continue after a patent expires and whether such revocation operates retrospectively. In the absence of a binding Indian ruling on this issue, the bench relied on the UK Supreme Court’s decision.
“We are currently reviewing the ruling, and have no further comment,” a Boehringer Ingelheim spokesperson said in response to Mint’s queries. Macleods Pharma has not yet responded.
Under patent law, a revocation plea is a legal request made to a court to cancel a patent that has already been granted. If the court allows it, the patent is removed and treated as if it was never valid.
Major ramifications
This ruling could have major consequences for damages in Indian pharma disputes. Indian generic drugmakers, which have mastered reverse engineering, often pursue patent challenges against innovators for life-saving or blockbuster drugs. Innovators, on the other hand, frequently file multiple patents for a single product to extend market exclusivity, a practice often described as 'evergreening'.
In many high-stakes cases, innovator companies file infringement suits seeking compensation, while generics companies file revocation petitions challenging the patent. Even after a patent expires, the patent holder can still seek money for alleged infringement during its lifetime. However, if the patent is later cancelled, the legal basis for those damages may disappear.
Take for example, Danish drugmaker Novo Nordisk and its blockbuster drug semaglutide, which is set to go off patent in India in March. Several Indian drugmakers such as Dr. Reddy's Laboratories, Sun Pharmaceutical Industries, and Natco Pharma have filed patent challenges or non-infringement suits in a bid to launch their versions earlier and gain an advantage.
In most such cases, the patent expires before the matter is finally decided. Historically, generic companies could still be liable to pay damages to the innovator if the final ruling went against them after patent expiry.
According to Pankaj Soni, partner and patent chair at Remfry & Sagar, the ruling does not make India more pro-generics than it already is. Instead, he said, it aligns India with major patent jurisdictions by making it clear that expiry is not a shield against validity challenges, especially when financial claims such as damages are involved.
'Greater litigation risk for patent holders'
Legal experts said the latest judgement significantly raises litigation risk for patent holders, as revocation could impact past royalties and licensing arrangements. The decision is expected to encourage generics to file more revocation petitions and adopt a more aggressive strategy, while forcing innovator companies to defend patent validity more carefully in high-stakes disputes.
“We can expect generic companies to be more aggressive in filing revocation petitions, knowing that the benefits extend beyond freedom to operate — they also neutralize damages exposure,” said Essenese Obhan, managing partner at Obhan Mason.
Hersh Desai, partner at Chitnis Desai, said the ruling could encourage patent holders to settle cases earlier. He said companies will now have to consider the risk that even an expired patent might later be cancelled, which could weaken or wipe out their claims for damages.
“Patent plaintiffs pressing damages/accounts will have to factor in that an adverse revocation order can retrospectively undercut their monetary claims. This may push them towards earlier settlements, narrower pleadings, or more conservative damages theories," Desai said.
According to Himanshu Deora, partner at King Stubb & Kasiva, the ruling is likely to change how pharma patent cases are fought.
Generics may adopt a dual strategy of challenging both infringement and validity simultaneously. Innovator companies, in turn, may need to assess patent strength more carefully before filing lawsuits and be cautious while seeking damages. Patent validity, Deora said, will become even more central to enforcement strategy.
Once a patent expires or is revoked, drug prices can fall sharply. In the case of life-saving drugs, this can be a major win for patients. For instance, Zydus Lifesciences launched a generic version of nivolumab at a significantly lower price compared to innovator Bristol-Myers Squibb after court clearance. Similarly, Natco Pharma launched a generic version of risdiplam at a fraction of the price charged by Roche.
In blockbuster segments such as weight loss, generics are vying for an early-mover advantage to capture a larger share of the market. Innovator brands such as Mounjaro, Wegovy and Ozempic have already crossed ₹1,000 crore in sales within a year of launch. Analysts estimate the market could grow to ₹2,000-3,000 crore by FY27 once patents expire.
While there is a higher risk of litigation hurdles, the ruling is unlikely to deter multinational pharmaceutical firms from bringing innovative products to India, industry experts said. "India remains too large and too strategically important a market to ignore. However, it does increase litigation risk and may prompt global companies to reassess how aggressively they enforce patents here,” independent pharma analyst Salil Kallianpur told Mint, adding that MNCs may double down on biologics and first-in-class innovation, where patent defensibility is stronger.
While this could embolden generic manufacturers, India may see "more strategic revocation petitions filed closer to expiry not just to enable launch, but to neutralize historical liability", he said.