India: A Hot Destination for IP Litigation

India has emerged as a major hub for IP litigation. With dedicated IP divisions functioning in High Courts such as Delhi, Madras and Calcutta, right-holders have increasingly turned to these forums for enforcement. The Delhi High Court, in particular, continues to lead this space; as per monthly reports published by these Courts, the Delhi High Court has handled nearly 4,000 IP-related commercial matters in the present year, with more than 100 new IP matters being filed every month. Indian courts have delivered numerous decisions that have shaped the IP dispute landscape and have made a remarkable impact globally.

Illustrative List of Case Law

Biopharmaceutical litigation

The Delhi High Court granted a landmark decision in favour of ER Squibb & Sons by restraining Zydus Lifesciences Limited for infringement of its patent concerning a monoclonal antibody, Nivolumab. The Court noted that the defendant’s biosimilar ZRC-3276 was admittedly similar to the reference biologic, essentially having similar amino acid sequencing to that of Nivolumab. These admissions were clearly traced to the defendant’s clinical trial applications, which named Nivolumab as the comparator.

The Court also noted the defendant’s product claimed conformity to the INN Nivolumab. Given that the plaintiff’s patent was mapped with 5C4 antibody (Nivolumab), the defendant’s product would also have the same sequencing. The defendant’s own test data showed that binding specificity of Opdivo (the plaintiff’s product) and ZRC-3276 were PD-1 antibodies that have higher binding affinity to human PD-1 receptors compared to other CD-28 family receptors, and do not bind substantially with human CD-28/CTLA4 or ICOS receptors. Thus, both products fall within the scope of the claims of the suit patent.

Ordinarily in patent infringement, a comparison has to be drawn between the claim of the patent and the infringing product; however, since the suit was a quia timet action, such claim mapping could not be produced. The plaintiffs had done the claim mapping with Nivolumab INN assigned by the WHO, which was used as the reference product by the defendant for the development of its biosimilar. Therefore, such an indirect comparison was permissible. The Court also held that the defendants had failed to clear the way and mere filing of a pre-grant opposition was insufficient. The Court held that, when a patent is prima facie found to be infringed, and is being exploited without licence, the balance of convenience tilts in favour of restraining the infringement. The Court also rejected the defendant’s challenge to validity of the patent and restrained the defendants from stockpiling the infringing drug during the term of the patent.

In Amgen Inc v The Assistant Controller of Patents and Another, the Madras High Court allowed the appeal filed by the patentee against refusal to grant patent. The subject invention related to lyophilised formulations containing certain excipients in a specific concentration for a therapeutic peptibody, referred to as Formula V.

The pre-grant opponent had argued that Formula V had already been disclosed in prior art, and that the application was therefore barred under Section 3(d) of the Patents Act for being mere use of a known process. The Court rejected this contention, observing that the cited prior art did not disclose any method for lyophilising the therapeutic peptibody of Formula V. Instead, the prior art only described the composition, not the lyophilisation method itself.

The Court further dismissed the objections under Section 3(e) and for insufficient disclosure. It noted that the objective of the claimed invention was to enhance the stability of the therapeutic peptibody through lyophilisation, whereas the cited prior art focused on increasing the protein concentration via lyophilisation. Therefore, for establishing synergistic effect, it was sufficient for the applicant to demonstrate interaction between the ingredients, and there was no requirement to furnish data showing pre-lyophilisation and post-lyophilisation.

In Novo Nordisk AS v Dr Reddy’s Laboratories Limited and Another, the Delhi High Court declined the plaintiff’s application to restrain the defendants from the manufacturing of Semaglutide in India. Novo Nordisk had alleged infringement of its patent concerning GLP-1 analogues used for treatment of Type 2 diabetes and obesity. The suit patent claimed the compound Semaglutide, which is widely marketed under the brand names Ozempic, Wegovy and Rybelsus.

The defendants challenged the validity of the suit patent and invoked the Gillette defence on infringement. At the interim stage, the burden rested on the defendants to demonstrate a “credible challenge” to the patent’s validity. The defendants argued that the Semaglutide compound as claimed in the suit patent lacked novelty for being prior claimed/disclosed in the genus patent. Specifically, example 61 of the genus patent referred to an Alanine (Ala) version of the Semaglutide compound and that the only distinction between example 61 and the suit patent was the substitution of “Ala” with “Aib” at the eighth position.

The Court observed that independent claim 1 of the genus patent broadly claimed a GLP-1 analogue comprising an amino acid sequence that could be selected from a broader group containing “Ala”, “Gly” “Val”, “Leu”, “11e”, “Lys”, “Aib”, etc. Further, in claim 16 of the genus patent, the patentee specifically identified “Aib” as the preferred amino acid at the eighth position. In light of this, the Court held that, for a person skilled in the art (in the present case, a “person in the know”, since inventors of the genus patent and the species patent were common), substituting “Ala” with “Aib” at the eighth position would be obvious. 

The Court also noted contradictions in the plaintiff’s position, noting that, while it claimed that no therapeutic drug was developed from the genus patent, in its statement of working (ie, Form 27) it nevertheless declared that the genus patent had been commercially worked, and filed common declarations with that of the species patent.

It needs to be emphasised that the defendants had already given an undertaking to not sell Semaglutide in India till the expiry of the suit patent. However, the defendants had sought to continue manufacturing for exportation to jurisdictions where the plaintiff held no patent rights over Semaglutide. The Court noted that, though there was a prima facie credible challenge to the patent’s validity, it would not release the defendants from their undertaking to not sell in India. This was because the defendants had failed to “clear the way” before commencing manufacture, reflecting procedural mala fides.

Patentability of diagnostic methods under Section 3(i) of the Patents Act

In a series of decisions, the Delhi High Court has clarified the scope of ineligible subject matter relating to diagnostic methods under Section 3(i) of the Patents Act.

In Natera Inc v Assistant Controller of Patents, the invention related to a non-invasive, in vitro method to detect and monitor genetic mutations associated with lung squamous cell carcinoma, using blood samples. The Court held that the claims were ineligible for grant under Section 3(i) of the Patents Act. It was held that Section 3(i) applies where the claimed process concerns diagnostic or therapeutic purposes, especially the activities that lie at the core of a medical practitioner’s training. At the same time, the Court clarified that such exclusion does not extend to patent applications concerning medical or surgical devices.

In EMD Millipore Corporation v Assistant Controller of Patents, the Court rejected the Patent Office’s objection under Section 3(i). The invention related to an improved method for quantitative analysis of biomolecules using infrared spectroscopy, where previously generated calibration data reused by refining the curve generation methodology through algorithmic and spectral adjustments is patentable. The Court held that, while the interpretation of a diagnostic curve cannot itself be patented, the present invention concerned a novel method of conducting the quantisation of biomolecules in a new form of infrared spectroscopy, which had a bearing on improving the efficiency and reliability of quantitative analysis by reducing calibration time. It therefore was not hit by Section 3(i).

On similar lines, in Sequenom Inc v Assistant Controller of Patents the Court refused a patent application concerning an in vitro method for determining presence of fetal aneuploidy. The Court noted that Section 3(i) does not differentiate between non-invasive prenatal testing and diagnostic testing. It was also held that a positive or negative for both tests would be covered under the provision.

Ex parte ad interim injunctions

In Astellas Pharma Inc and Another v Everest Pharmaceuticals Limited and Others, the High Court granted an ex parte injunction against the defendants for illegally selling the patented compound Gilternib in India. The modus operendi involved manufacturing the drug in Bangladesh and illegally bringing it into the Indian market, including selling it through e-commerce websites. The Court restrained the defendants and their agents from dealing with these products, and issued directions to the e-commerce website to delist and remove the infringing web links.

In Astrazeneca Ab and Another v Glarea Healthcare LLP and Others, the High Court granted an ex parte ad interim injunction to the plaintiffs for their patented compound Osimertinib, used for treatment of non-small cell lung cancer (NSCLC). The Court restrained the defendants and their agents involved in unauthorised manufacture and sale of the drug in India.

Sufficient disclosure requirement

In The Regents of the University of California v The Controller of Patents, the Court examined the sufficiency of disclosure requirement in a patent application relating to a vaccine composition designed to induce an immune response to salmonella. The claims covered both the genetically modified salmonella strains and the vaccine composition itself.

The Court noted that the inventive contribution lay in the deliberate introduction of mutations such as insertions, deletions and substitutions at gene sites to attenuate virulence. However, the complete specification disclosed only deletion mutations, and provided no sufficient disclosure regarding insertion and substation mutations. This omission was held to violate the mandatory requirement of sufficient disclosure under Section 1(3)(1).

The Court further held that, since the recombinant salmonella claimed in the subject patent application was a modified bacteria which would not be accessible to the public, it was also liable to be deposited in the recognised depository, according to the Budapest Treaty referred to in Section 10(4)(d)(ii) of the Patents Act.

Judgment on admissions

In GSP Crop Science Limited v BR Agrotech Limited and Another, the suit concerned a specific formulation of two agrochemical ingredients, namely Pyriproxyfen and Diafehthiuron, which was commercialised by the plaintiffs in their insecticides, named SLR 525. The defendants used an identical formulation and admitted that they marketed and sold the product, believing that their regulatory licence protected them. This admission was recorded in their affidavit.

The Court decided the suit using its powers under Order XII Rule 6 of the Code of Civil Procedure, based on “admissions of fact” made by the defendant. The Court noted that, in light of admissions, it was impossible for the defendant to succeed, and despite sufficient opportunity it could not provide any explanation as to why such a decision should not be made. The Court mapped the patent in question to the ingredients of the defendant’s product and held them liable for infringing actions. In light of the sales carried out by the defendants, the Court decreed the suit in favour of the plaintiffs and awarded granted damages.

Scope of amendments to patent applications

In Abbvie Biotherapeutics Inc and Another v Assistant Controller of Patents, a single judge of the Delhi High Court refused to grant amendments to the patent application in an application concerning therapeutic methods using anti-cMet antibody-drug conjugates (ADCs) in treating cMet-overexpressing cancers, dosing schedules, dosage ranges and strategies for resistant tumours. In order to overcome the concerned objection under Section 3(i), the applicant filed amended claims for a product ADC claim instead of a method claim, as filed. The Court noted that the amended claims omitted references to dosing schedules. The Court also noted that the amended claims omitted references to several limitations from the originally filed claims and were an attempt to expand the scope of protection, instead of narrowing it down, which is permissible by way of disclaimer. Thus, it was held that the proposed amendments were beyond the scope of Section 59(1) of the Patents Act.

In Fresenius Medical Care Deutschland Gmbh v Controller General of Patents, the Court allowed the amendments for an invention concerning microvesicles (MVs) derived from adult stem cells for use in the therapeutic treatment of a tumour disease. The patent applicant incorporated the features of the dependent claim into the independent claim. The Court noted that, since the amended claims were only in the nature of an explanation and disclaimer, they did not broaden the scope of unamended claims.

Right to cross-examination before the Patent Office

In Novartis AG v Controller of Patents and Designs and Another, the Court disallowed a writ petition filed by Novartis AG requesting to cross-examine opponent experts who had adversely opined against the validity of Novartis’s Indian Patent No 414518. The subject patent was granted in December 2022, and a post-grant opposition was filed against the granting of said patent. Notably, the opponents had filed further evidence in July 2024. The filing of further evidence was contested by the patentee but was permitted by the Controller and later upheld by the High Court, granting leave to the patentee to file rebuttal evidence in a specific timeline. This rebuttal evidence was filed in June 2025.

The patentee also filed a petition seeking cross-examination of the opponent’s experts in July 2025 concerning the affidavits dated July 2024. The request was deferred by the Patent Controller, and the Controller went on to decide the post-grant opposition. This led to the filing of a writ petition by the patentee before the High Court. The Court, however, denied the request filed by the patentee. It was held that in earlier writ petitions the patentee had only sought leave to file rebuttal evidence and did not ask for leave to cross-examine the opponent’s experts, either before the Court or before the Controller. It was further clarified that, as per the Patent Act and related Rules, a right to seek cross-examination of an expert has to be expressly sought. If no such request is made, the affidavit is read in evidence as it is. The appropriate stage to request cross-examination of an opponent’s expert is at the earliest opportunity, after service of the expert’s evidence. Said right is to be elected for use by the patentee on the basis of its reply and even before it elects to file its own rebuttal evidence.

Maintainability of revocation petition after expiry of the patent

In Macleods Pharmaceuticals Ltd v The Controller of Patents and Another, the Court clarified that the scope of a revocation petition under Section 64 of the Patents Act and the defence of invalidity under Section 107 of the Patents Act are entirely different. It was further held that a patent infringement suit does not become infructuous upon expiry of the patent, as the cause of action – in so far as damages – survives. Applying the same rationale, it was observed that upon expiry of the patent it cannot be said that the revocation petition cannot survive. If the defendant succeeds in its revocation petition and the subject patent is revoked, the plaintiff’s suit would be liable to be dismissed. Hence, the revocation petition cannot become infructuous merely upon expiry of the patent. 

Delay in ministerial act of uploading the order cannot permit wrongful acceptance of a pre-grant opposition against the patentee

In Vertex Pharmaceuticals v Controller General of Patents, a single judge of the High Court effectively dismissed a pre-grant opposition that was filed by an opponent on the same date as that of a grant order. The Court held that the patent was granted on 28 November 2023, and before the signing of said order no pre-grant opposition was filed by an opponent. It was held that, after signing of the order, the Controller had become functus officio and thus was no longer seized of the patent application. Hence, a patent application filed after the point of signing the order cannot be considered, even if it was filed on the same date and the patent certificate was uploaded at a later date.

Quia timet injunctions

In Helsinn Healthcare SA v AET Laboratories Private Limited and Another, a single judge of the High Court denied granting a quia timet injunction to the plaintiff. The Court noted that there was absence of credible apprehension against the defendants for launching the alleged drug covered by the patent. The single judge held that mere filing of post-grant opposition by the defendant itself and business discussion for developing the products for the foreign market cannot be said to be apprehension of an imminent threat. It was clarified that, before commercial launch, a party has to conduct clinical trials and testing and obtain regulatory approval – no such approvals had been obtained by the defendants. Moreover, the defendants’ marketing material only showed that the impugned products were “under development” drugs. The Court also noted that both defendants were located outside the jurisdiction of the Court and none of them had any offices in Delhi. The Court further noted that mere accessibility of the defendant’s website would not amount to specific targeting of customers in Delhi, and no jurisdiction was made out.

Coverage v disclosure

For several years, Indian courts have grappled with the question of whether coverage of a compound in a genus patent would ipso facto invalidate the specifically disclosed compound in the species patent. In F Hoffman-La Roche AG and Another v Natco Pharma Limited, the Division of the Delhi High Court clarified the law surrounding this question. The Court rejected the view that mere coverage of the claimed compound amounts to disclosure of the claim in the species patent, unless the genus contains requisite teaching for a person skilled in the art. Instead, the bench took the view that coverage is relevant for deciding infringement and disclosure is relevant for deciding (enabling disclosure) invalidity. Therefore, if the defendant’s product falls within the broad coverage of the Markush, said entity would be liable for infringement. 

“Person in the know” test for determining obviousness

A Division Bench in AstraZeneca v Intas Pharmaceuticals Ltd (2013) had earlier devised a new test: where the inventors of the genus patent and the species patent were the same, the aspect of obviousness in such case has to be assessed from the perspective of the inventor, who would be the “person in the know”. Therefore, in the case of genus and species patents, if a species was obvious to a person skilled in the art from the genus patent, such species would be more obvious to the person in the know.

The Division Bench has upheld the application of this test in F Hoffman-La Roche AG and Another v Natco Pharma Limited. It was held that the inventor cannot be permitted to keep the invention out of the public domain whereby the modification would be obvious to a person in the know. The Court has lent its reasoning for preventing evergreening of the invention. The decision primarily appears to have been made to ensure that drugs for treating spinal muscular atrophy are widely accessible to the public at large. The decision leaves more questions than answers, and the Patents Act lacks any support for the new “person in the know” test.

Assessment of therapeutic efficacy

In Tapas Chatterjee v Assistant Controller of Patents and Another, the Division Bench of the Delhi High Court clarified the scope of the “efficacy requirement” under Section 3(d) of the Patents Act. It was noted that, for application of Section 3(d), the first condition is that there must be a “known process” forming the subject matter of the patent. Said provision would also not apply if the later process results in a new product or employs at least one new reactant.

The subject invention concerned a multi-step chemical process for treating industrial effluents and recovering useful by-products. The Patent Office had rejected the application by holding that the steps involved were standard chemical operations and that the claimed process was merely the use of a known process. The Division Bench set aside the findings of the Assistant Controller, noting that the comparison performed was insufficient and lacked a feature-by-feature comparison with the cited prior arts. The Court also held that the “person skilled in the art” test was irrelevant in determining the applicability of Section 3(d). 

Letters rogatory for a parallel US litigation

In Pfizer Inc and Others v Softgel Healthcare Pvt Ltd, the Madras High Court addressed Pfizer’s request to enforce letters rogatory issued by the US District Court, Delaware. The petition sought appointment of a commissioner to obtain documents and record testimony from Softgel, which was not a party to the US litigation but allegedly possessed information relating to the ANDA product at issue. Softgel opposed the petition, citing it as a “fishing expedition”. The Madras High Court, however, emphasised India’s obligation under the Hague Evidence Convention and international comity, noting that execution of letters rogatory is permissible unless it conflicts with Indian law.

Writ jurisdiction against pre-grant opposition

In Adiuvo Diagnostics Pvt Ltd v Union of India, the petitioner had challenged the rejection of its pre-grant opposition and the granting of a patent to a foreign applicant. The petitioner argued that the order was perverse as it failed to consider critical evidence, including expert affidavits relied upon in the opposition. The respondents objected to maintainability of the petition. However, the Court reaffirmed that, although the petitioner had other statutory remedies open, its jurisdiction under Article 226 cannot be ousted where there is failure to consider material evidence or where the decision-making process is perverse. It reviewed the impugned order and observed that the Patent Office had failed to consider the affidavits of three experts. The Court remanded the matter for re-hearing and decision in a time-bound manner.

The Competition Commission does not have power to investigate disputes concerning abuse of patents

In the landmark decision in Swapan Dey v Competition Commission of India and Another, the National Company Law Appellate Tribunal put to rest the complaints alleging that Vifor International abused its dominant position, by enforcing patent rights related to ferric carboxymaltose injections for treatment of iron-deficiency anaemia.

The tribunal clarified the legal position on the Competition Commission’s jurisdiction on such matters, holding that the Patents Act prevails over the Competition Act in cases involving patent enforcement. It further noted that the Competition Act itself extends specific protection to patentees; therefore, initiating infringement proceedings cannot be construed as anti-competitive or abuse of dominance.

Decriminalisation of the Patents Law

Parliament enacted the Jan Vishwas (Amendment of Provisions) Act, 2023, which came into force in August 2023, with the objective of decriminalising and rationalising offences while promoting a trust-based governance framework. The legislation had amended the Patents Act by curtailing several penalties and fines and by simplifying the adjudication of offences and related appeals. Continuing this reform, the Patents (Amendment) Rules, 2025 operationalise this shift towards a structured framework. The amended rules have brought the following changes:

• administrative adjudication framework – a new Chapter XIV-A has been introduced to govern contraventions that earlier attracted criminal penalties under Sections 120, 122 and 123 of the Patents Act;
• electronic filing of complaints – complaints concerning contraventions must now be filed electronically under Form 32;
• time-bound enquiry – the amended rules mandate digital show-cause notices and provide a structured, time-bound opportunity for response, hearing, consideration of evidence and final decision by the authority; and
• appellate mechanism – an appeal may be preferred against the adjudicating officer’s decision within 60 days, electronically under Form 33.

Conclusion

The path of pharmaceutical patent litigation in India, as shown in this chapter, indicates a system that has shifted from uncertainty to greater confidence and better enforcement. Indian courts today are knowledgeable, methodical and aware of commercial realities. Patent disputes are no longer seen as theoretical arguments over validity but as high-stakes commercial matters with real market impacts.

A key aspect of this change is the courts' ongoing engagement with science, covering small molecules, biologics, biosimilars, and formulation and process patents. The increased use of scientific advisers, structured claim processes and detailed infringement mapping shows a move away from broad reasoning to precise, evidence-based decision-making. At the same time, ongoing discussions about genus and species claims, therapeutic effectiveness and selection inventions indicate that the courts are actively redefining the line between true innovation and unacceptable monopoly extension. Another important development is the clear change in the enforcement environment.

The increase in pre-launch and quia timet actions, more careful examination of interim injunctions, and the clear assignment of the burden of proof on defendants together reveal a judiciary that is increasingly unwilling to accept speculative patent enforcement or casual at-risk generic launches. Patent rights are now viewed as commercial assets rather than just legal privileges, with courts fully aware that disruptions during the patent term can lead to lasting market damage.

These judicial changes occur alongside regulatory updates, digitisation of patent management, and the easing of penalties for procedural mistakes, all suggesting a system that is quicker, more open and better suited to industry needs. In conclusion, Indian pharmaceutical patent litigation has entered a phase that emphasises strategic enforcement, scientific accuracy and commercial realism. For legal professionals and the industry, the main question is no longer whether patents will be enforced in India but rather how early, how specifically and how decisively that enforcement will take place.