A Division Bench of Delhi High Court has turned a procedural question into a market impacting doctrine. For generics, it strips away a key layer of residual liability. For originators, it converts weak, near-expiry patents into a potential post-mortem risk.
The Delhi High Court's division bench ruling in Boehringer Ingelheim v. Comptroller of Patents, upholding the maintainability of section 64 revocation petitions, even post-patent expiry and alongside section 107 invalidity defenses in infringement suits could reshape India's $50 billion pharma market by tilting the balance towards generics and intensifying scrutiny on innovator patents.
For originators, patent expiry no longer brings closure. The ruling forces multinationals to reckon with the possibility that yeasr of enforcement can unravel on the post-expiry validity finding neutralising damages and raising litigation costs.
For India's generic drugs industry, the order brings clarity. Companies like Macleods, Dr. Reddy's, Sun Pharma and Cipla can now challenge questionable patents even after expiry, clearing damages liability and accelerating market entry, particularly in chronic disease segments where affordable access matters most.
Why does the ruling matter for generics?
India is the world's largest supplier of generic drugs and is widely recognised for providing affordable vaccines and high-quality medicines.
Over time, the Indian pharmaceutical sector has developed into a dynamic and diversified industry, now ranked third globally in pharmaceutical production by volume and 14th by value. The sector has expanded at a compound annual growth rate of 9.43% over the past nine years and contributes about 1.72% into India's GDP. In this landscape, where a revocation petition dies with the patent has been the invisible fault line for a very long time.
The timing of the ruling coincides with India's pharma patent cliff, as a wave of blockbuster drugs lose exclusivity between 2023 and 2030 in key markets. Generic entry after expiry typically drives prices down by 50-80% within months.
For generics, market valued around $26-28 billion in 2024-25 and projected to grow at roughly 6-7% annually, the ability to posthumously knock out fragile patents and with them, past damages exposure could materially influence launch decisions, pricing strategies and settlement dynamics across multiple areas.
“This strengthens the incentive to challenge questionable pharma patents, knowing that a successful revocation will wipe out the patentee's enforcement position ab initio,” said Alay Razvi, managing partner, Accord Juris. “Generics can neutralise not only injunctive relief but also monetary claims based on invalid patent, even if the suit continues after expiry.”
B. Shravanth Shankar, managing partner, B. Shankar Advocates LLP, calls it a structural shift in bargaining power.
“The ruling constitutes a significant victory for generic manufacturers because it dismantles the strategic advantage patentees historically derived from protracted litigation timelines,” he said. “A patentee can no longer rely on the mere subsistence of a patient during the period of alleged infringement if its validity is subsequently negated.”
For domestic manufacturers and MSMEs, particularly in high-volume therapies like diabetes, hypertension and oncology, the ability to retrospectively clear the deck on weak patents could be decisive in boardroom go/no-go calls on the launches. An invalid patent, one that should never have been granted, should not be permitted to generate enforceable monetary rights simply because time ran out before a challenge could be decided.
Enhanced litigation risk
The immediate effect of the ruling is to protect defendants already facing damages suits on the back of expired patents. The larger question is whether it will be embolden generics to file more aggressive revocation actions, including against patents that have lapsed but still anchor pending monetary claims.
Although the order does not expand the grounds on which patents can be attacked, it still removes the safety net originators quietly enjoyed, the assumption that expiry makes validity disputes academic over time.
“Defendants would generally always defend any patent infringement claim by a revocation or a counter claim. The decision only clarifies that a revocation petition would be maintainable and would continue to survive, even after the patent of which revocation is sought expires,”
said Swati Sharma, partner, (head – intellectual property), Cyril Amarchand Mangaldas.
“The Court made it clear that revocation proceedings can continue post-expiry, and if successful, they erase the patent an initio. However, this does not create unfair risk — it simply aligns enforcement with the fundamental principle: a patent that was never valid should not generate enforceable rights,”
said Ekta Rai, Advocate, Delhi High Court.
Effect on ongoing and future infringement suits
The ruling may trigger a wave of post-expiry revocation challenges, or at least a more sustained and deliberate use of revocation proceedings beyond the patent's commercial life.
“If the patent is ultimately revoked, that revocation relates back to the date of grant, effectively nullifying the legal basis on which damages are claimed,” said Dr. Sudhir Raja Ravindran Attorney-At-Law, Solicitor (England & Wales) at Altacit Global. “In practical terms, this means that patentees pursuing damages for alleged past infringement remain exposed to a full validity challenge, even after the patent term ends.”
“This ruling increases litigation risk for patent holders, but in a targeted way,” said Ankit Sani, partner, Ajay Sahn i& Associates. “The risk is not that expiry creates fresh liability, rather that expiry no longer ends the validity war when damages are still being pursued. Patentees will now have to price in the possibility that a damages heavy strategy can keep the dispute alive while simultaneously inviting a determination that retrospectively erases the patent's legal footing.”
Case in decision
The Boehringer-Macleods dispute over Linagliptin, marketed by Boehringer as Trajenta, dealt with Indian patent IN 243301, granted for Linagliptin, which expired on 18 August 2023. Macleods had filed a revocation petition under section 64 before the Delhi High Court in February 2022, while Boehringer separately sued for infringement before the Himachal Pradesh High Court.
Boehringer's patent was in force from 5 October 2022 to 18 August 2023, roughly 10 months post-grant, during which the Himachal court granted an ad-interim injunction restraining Macleods from selling its Linagliptin generic. That injunction was vacated only when the patent expired, but Boehringer's suit continues, pressing claims for damages and an account of profits for the injunction period.
The Division Bench now held that Macleods remains a “person interested” entitled to pursue revocation because of that surviving monetary exposure. If the revocation petition succeeds, IN 243301 will be treated as though it never existed from the date of grant and Boehringer’s damages that profits claim would, in law, collapse with it.
Source: ET Legal World
