Boehringer Ingelheim International GmbH Vs. Eris Lifesciences Limited

A credible challenge to patent validity, requires serious question to be tried

Introduction

In the intricate world of pharmaceutical patents, where innovation meets the crucible of legal scrutiny, the case of Boehringer Ingelheim Pharma GmbH & Co. KG Vs. Vee Excel Drugs and Pharmaceuticals Pvt. Ltd. and connected matters, decided by the Delhi High Court on March 29, 2023, stands as a landmark exploration of patent validity and interim relief. This batch of six suits revolves around Indian Patent No. 243301 (IN ‘301), covering Linagliptin, a critical drug for type 2 diabetes management. Boehringer Ingelheim, a global pharmaceutical leader, sought to restrain multiple Indian generic manufacturers from producing and selling Linagliptin, alleging infringement of IN ‘301.

The defendants, including Vee Excel, Alkem Laboratories, Micro Labs, Natco Pharma, and Mankind Pharma, countered by challenging the patent’s validity, alleging it was an impermissible attempt to extend monopoly rights beyond the expired genus patent, IN ‘719. The Delhi High Court grappled with complex issues of prior claiming, evergreening, and public interest, ultimately denying interim injunctions. This case study delves into the factual and procedural intricacies, legal issues, parties’ arguments, judicial precedents, the court’s reasoning, and the broader implications, offering a vivid narrative of innovation under legal siege in India’s patent regime.

Detailed Factual Background

Boehringer Ingelheim Pharma GmbH & Co. KG, a Germany-based pharmaceutical giant, and its Indian subsidiary, Boehringer Ingelheim (India) Pvt. Ltd., are renowned for developing and marketing innovative drugs. The plaintiffs hold Indian Patent No. 243301, granted on October 5, 2010, titled “8-(3-Aminopiperidin-1-yl)-Xanthine Compounds,” covering Linagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor used to treat type 2 diabetes. Marketed under brands like Trajenta, Trajenta Duo, and Ondero, Linagliptin was launched in India in 2012 and 2014, achieving significant commercial success. The patent, valid until August 18, 2023, grants Boehringer exclusive rights under Section 48 of the Patents Act, 1970, to prevent unauthorized manufacture, use, sale, or importation. The plaintiffs emphasized that no pre-grant or post-grant oppositions were filed against IN ‘301, and it was upheld in China, reinforcing its global validity. Boehringer’s substantial R&D investments, coupled with its licensing agreements with Lupin and Eli Lilly, underscored its commercial stake in Linagliptin.

The defendants, Indian pharmaceutical companies including Vee Excel Drugs and Pharmaceuticals Pvt. Ltd., Alkem Laboratories Ltd., Micro Labs Limited, Natco Pharma Limited, and Mankind Pharma Limited, are engaged in manufacturing and selling generic Linagliptin 5 mg tablets. Boehringer alleged that these products infringed IN ‘301, as they contained Linagliptin without authorization. The plaintiffs highlighted prior successful enforcement actions against other infringers, such as MSN Laboratories, before the Himachal Pradesh High Court. A key contention was the relationship between IN ‘301 and an earlier patent, IN ‘719, titled “Xanthine Compounds,” a genus patent covering a Markush formula that expired on February 21, 2022. The defendants argued that Linagliptin was covered and claimed in IN ‘719, rendering IN ‘301 an invalid attempt at evergreening to extend monopoly rights. They pointed to Boehringer’s admissions in prior litigations and regulatory filings, including Form 27 statements, which listed identical Linagliptin products for both patents, suggesting that IN ‘301 duplicated IN ‘719’s scope.

Boehringer countered that IN ‘301 was a species patent, claiming specific commercial embodiments of Linagliptin developed through further research after IN ‘719’s filing. They argued that Linagliptin was neither specifically claimed nor disclosed in IN ‘719, and the genus patent’s Markush formula did not anticipate IN ‘301’s inventive step. The plaintiffs also noted that the defendants began commercializing Linagliptin only after IN ‘719’s expiry, but this did not negate infringement of IN ‘301, which remained valid until August 2023. The defendants, in turn, emphasized public interest, highlighting their significantly cheaper Linagliptin products compared to Boehringer’s imported drugs, crucial for affordability in a country with high diabetes prevalence.

Detailed Procedural Background

The dispute unfolded through six suits filed before the Delhi High Court: CS(COMM) 239/2019, CS(COMM) 240/2019, CS(COMM) 236/2022, CS(COMM) 237/2022, CS(COMM) 238/2022, and CS(COMM) 296/2022. Boehringer sought permanent injunctions to restrain the defendants from infringing IN ‘301, alongside damages and other reliefs. Each suit was accompanied by applications for interim injunctions under Order XXXIX, Rules 1 and 2 of the Code of Civil Procedure (CPC), 1908, specifically I.A. 6797/2019, I.A. 6802/2019, I.A. 5801/2022, I.A. 5806/2022, I.A. 5811/2022, and I.A. 7109/2022. The defendants filed written statements and counterclaims seeking revocation of IN ‘301 under Section 64 of the Patents Act, 1970, alleging prior claiming, lack of inventive step, and evergreening.

In CS(COMM) 239/2019 and CS(COMM) 240/2019, summons were issued on May 10, 2019, with ad interim injunctions granted, restraining Vee Excel from manufacturing Linagliptin tablets. These orders persisted until the final judgment. For CS(COMM) 236/2022, CS(COMM) 237/2022, and CS(COMM) 238/2022, summons were issued on April 19, 2022, with a pro-tem arrangement agreed upon, prohibiting the defendants from manufacturing or selling Linagliptin, except for existing stock, pending disclosure of stock details. A similar arrangement was adopted in CS(COMM) 296/2022 on May 9, 2022. The court heard arguments on multiple dates in January 2023, reserving judgment on January 27, 2023, and delivering it on March 29, 2023.

Issues Involved in the Case

The case presented several pivotal legal questions at the nexus of patent law and interim relief:

Whether the age of IN ‘301, an “old” patent nearing expiry, warranted a presumption of validity for interim injunction purposes?

Whether the absence of pre-grant or post-grant oppositions, or the belated filing of revocation petitions, strengthened the plaintiffs’ claim to interim relief?

Whether the defendants raised a credible challenge to IN ‘301’s validity, particularly on grounds of prior claiming under Section 64(1)(a), evergreening, or non-compliance with Section 3(d) of the Patents Act?

Whether Boehringer’s assertions that Linagliptin was covered by both IN ‘719 and IN ‘301 in prior litigations estopped them from claiming it was only specifically claimed in IN ‘301?

Whether denying an interim injunction would cause irreparable harm to Boehringer, or if monetary damages could suffice, given its licensing arrangements?

How public interest, particularly access to affordable anti-diabetes drugs, should influence the court’s equitable discretion in granting interim relief?

Detailed Submission of Parties

Boehringer’s counsel argued that IN ‘301, granted in 2010 and valid until August 2023, conferred exclusive rights under Section 48, which the defendants violated by manufacturing Linagliptin without licenses. They highlighted the patent’s enforcement against other infringers, its global validity, and the absence of oppositions in India, citing National Research Development Corp. of India vs. Delhi Cloth & General Mills (1979 SCC OnLine Del 206) to argue that an old, worked patent should be presumed valid for interim relief. The plaintiffs contended that IN ‘719, a genus patent, did not specifically claim or disclose Linagliptin, as its Markush formula was too broad, and IN ‘301’s claims were distinct, supported by further research. They dismissed the defendants’ reliance on Form 27 filings as irrelevant, arguing that these did not admit invalidity. Boehringer rejected evergreening allegations, asserting that IN ‘301 was a legitimate species patent, not a patent of addition, and that prior art claims were hindsight-driven, citing FMC Corporation vs. Best Crop Science LLP (2021) 87 PTC 217 for the defendants’ burden to establish a credible challenge. On public interest, they argued that the Patents Act’s compulsory licensing provisions addressed affordability, and monetary damages could not compensate for market erosion.

The defendants’ counsel argued that IN ‘301 was invalid under Section 64(1)(a) for prior claiming, as Linagliptin was covered and claimed in IN ‘719, which expired in February 2022, rendering it public domain. They cited Boehringer’s admissions in Indian and Canadian litigations, Form 27 filings, and a 2008 reply to the Indian Patent Office’s Examination Report, where Linagliptin was listed among 371 compounds to secure IN ‘719, as evidence of coverage. The defendants invoked Section 13(4) and Bishwanath Prasad Radhey Shyam vs. Hindustan Metal Industries (AIR 1982 SC 1444) to argue that no presumption of validity exists, regardless of the patent’s age or lack of oppositions. They accused Boehringer of evergreening to extend monopoly rights, violating Sections 3(d), 10(4), and 53(4), and cited AstraZeneca AB vs. Intas Pharmaceuticals Ltd. (MANU/DE/1939/2020) and its Division Bench affirmation ((2021) 87 PTC 374) as controlling precedent. The defendants emphasized public interest, noting their significantly cheaper Linagliptin (a daily-use drug for diabetes) and Boehringer’s importation practices, arguing that monetary damages could compensate the plaintiffs, who licensed IN ‘301 to Lupin and Eli Lilly. They also alleged non-disclosure of material information under Section 8, further invalidating IN ‘301.

Detailed Discussion on Judgments Cited by Parties

The court’s analysis was shaped by a robust array of precedents, each contextualized to address patent validity, interim injunctions, and evergreening. The key judgments, their complete citations, and their relevance are as follows:

Bishwanath Prasad Radhey Shyam vs. Hindustan Metal Industries, AIR 1982 SC 1444: The Supreme Court held that Section 13(4) clarifies that patent grants do not guarantee validity, which can be challenged in revocation or infringement proceedings. The court used this to reject Boehringer’s claim of presumed validity for IN ‘301, affirming the defendants’ right to challenge it.

National Research Development Corp. of India vs. Delhi Cloth & General Mills, 1979 SCC OnLine Del 206: The Delhi High Court suggested that for old, worked patents (over six years), courts may presume validity for interim injunctions unless credibly challenged. Boehringer relied on this, but the court doubted its applicability, citing F. Hoffmann-La Roche vs. Cipla (2008 SCC OnLine Del 382), which treated it as a rule of caution, not practice.

F. Hoffmann-La Roche Ltd. vs. Cipla Ltd., 2008 SCC OnLine Del 382: A Single Judge held that the six-year rule is a cautionary principle, not a mandatory presumption, as patents remain vulnerable to challenge. The court adopted this to negate Boehringer’s reliance on IN ‘301’s age.

F. Hoffmann-La Roche Ltd. vs. Cipla Ltd., ILR (2009) Supp. (2) Delhi 551: The Division Bench clarified that even patents surviving pre-grant and post-grant challenges can be revoked on new grounds, reinforcing Section 13(4)’s stance against presumed validity, which supported the defendants’ challenge.

AstraZeneca AB vs. Intas Pharmaceuticals Ltd., MANU/DE/1939/2020: The court held that a credible challenge to a species patent’s validity, based on prior claiming in a genus patent, negates interim injunctions, especially when evergreening is alleged. The court found this directly applicable, given similar facts involving Linagliptin’s coverage in IN ‘719.

AstraZeneca AB vs. Intas Pharmaceuticals Ltd., (2021) 87 PTC 374 (DB): The Division Bench upheld the single judge, emphasizing that successive patents for the same invention violate the Patents Act’s intent to limit monopoly terms, supporting the defendants’ evergreening argument.

Novartis AG vs. Union of India, (2013) 6 SCC 1: The Supreme Court rejected distinctions between coverage and disclosure, holding that a patent’s claims must align with its disclosure to prevent evergreening. The court applied this to find that Boehringer’s claim that Linagliptin was not disclosed in IN ‘719 was untenable, given prior admissions.

Novartis AG vs. Natco Pharma Limited, 2021 SCC OnLine Del 5340: A Coordinate Bench distinguished AstraZeneca, suggesting it was fact-specific, but the court declined to follow it, finding AstraZeneca’s facts closely aligned with the present case and binding as a Division Bench ruling.

FMC Corporation vs. Best Crop Science LLP, (2021) 87 PTC 217: The Delhi High Court held that a credible challenge to validity requires cogent material, which Boehringer cited to argue the defendants’ burden. The court noted this preceded AstraZeneca’s Division Bench ruling and was less relevant.

FMC Corporation vs. GSP Crop Science Private Limited, 2022 SCC OnLine Del 3784: The court held that serial patenting to extend monopolies is impermissible under Section 3(d), supporting the defendants’ evergreening claim against IN ‘301.

Bristol-Myers Squibb Company vs. J.D. Joshi, MANU/DE/1889/2015: Cited in AstraZeneca, it was clarified that it does not limit defendants’ rights to challenge validity under Section 107, supporting the defendants’ position.

Smith vs. Grigg Ltd., (1924) 41 RPC 149 (UK): The origin of the six-year rule, it was referenced in National Research but doubted by the court, given India’s statutory framework under Section 13(4).

These precedents provided a comprehensive lens for evaluating IN ‘301’s vulnerability, the propriety of interim relief, and the perils of evergreening.

Detailed Reasoning and Analysis of Judge

The court delivered a meticulous judgment, applying the triple test for interim injunctions—prima facie case, balance of convenience, and irreparable harm—while addressing the defendants’ challenge to IN ‘301’s validity. The court framed four key issues: whether old patents presume validity, whether lack of oppositions or belated revocation petitions favored Boehringer, whether the defendants raised a credible challenge, and whether the balance of convenience supported an injunction.

On the first two issues, the court relied on Section 13(4) and Bishwanath Prasad to hold that no presumption of validity exists for any patent, old or new, as the Patents Act lacks a provision akin to Section 31 of the Trademarks Act, 1999. The court rejected Boehringer’s reliance on National Research, citing F. Hoffmann-La Roche (2008) to treat the six-year rule as cautionary, not mandatory. It further held that the absence of oppositions or delayed revocation petitions did not bolster IN ‘301’s validity, as challenges could be raised at any stage, per AstraZeneca.

On the third issue, the court found a credible challenge to IN ‘301’s validity under Section 64(1)(a) for prior claiming. Boehringer’s admissions in CS(COMM) 239/2019 and CS(COMM) 240/2019, Canadian litigation against Sandoz, and the 2008 reply to the Patent Office’s Examination Report for IN ‘719, where Linagliptin was listed among 371 compounds, confirmed its coverage in the genus patent. Identical Form 27 filings for both patents further evidenced that both protected the same Linagliptin products, violating Section 10’s prohibition on multiple patents for one invention. The court invoked Novartis to reject Boehringer’s distinction between coverage and disclosure, holding that Linagliptin’s inclusion in IN ‘719’s claims negated IN ‘301’s novelty. The court also found prima facie evidence of evergreening, as IN ‘301 extended monopoly rights beyond IN ‘719’s expiry, contrary to Sections 3(d), 10(4), and 53(4), and supported by AstraZeneca and FMC vs. GSP Crop Science. The court declined to assess other revocation grounds (e.g., obviousness, non-disclosure under Section 8), reserving them for trial.

On the balance of convenience, the court applied AstraZeneca to hold that it favored the defendants. Boehringer’s 20-year monopoly under IN ‘719, its importation practices, and licensing to Lupin and Eli Lilly indicated that monetary damages could compensate any loss, as the plaintiffs sought to monetize IN ‘301. The court emphasized public interest, noting Linagliptin’s role as a daily-use anti-diabetes drug and the defendants’ significantly cheaper products, critical amid India’s high diabetes prevalence and post-COVID comorbidities. Denying the injunction would cause no irreparable harm to Boehringer, but granting it would harm the defendants and public access to affordable drugs.

The court distinguished the Himachal Pradesh High Court’s ruling in Boehringer vs. MSN Laboratories (OMP No. 85/2022), finding it factually erroneous for relying on IN ‘719’s Examination Report as pertaining to IN ‘301, and legally inconsistent with Novartis and AstraZeneca for distinguishing “covered” and “encompassed.” The court concluded that Boehringer’s attempt to approbate and reprobate—claiming Linagliptin’s coverage in IN ‘719 for prior reliefs but denying it for IN ‘301—was impermissible, reinforcing the defendants’ credible challenge.

Final Decision

The Delhi High Court dismissed all interim injunction applications on March 29, 2023, with costs of Rs. 2,00,000 to each defendant and Rs. 2,00,000 to the Delhi High Court Legal Services Committee. The interim orders in CS(COMM) 239/2019 and CS(COMM) 240/2019, and pro-tem arrangements in the 2022 suits, were vacated. The defendants were permitted to manufacture and sell Linagliptin products, subject to regulatory approvals, and ordered to maintain half-yearly accounts. The court clarified that its observations were preliminary and would not affect the final trial outcome.

Law Settled in this Case

The judgment clarified several principles governing patent disputes and interim relief in India:

No presumption of validity exists for patents, regardless of age or lack of oppositions, as per Section 13(4), and challenges can be raised at any stage (Bishwanath Prasad, AstraZeneca).

A credible challenge to patent validity, requiring only a serious question to be tried, negates interim injunctions, particularly when prior claiming under Section 64(1)(a) is established (AstraZeneca, Novartis).

Evergreening through successive patents for the same invention violates Sections 3(d), 10(4), and 53(4), and courts must guard against attempts to extend monopolies beyond the statutory 20-year term (AstraZeneca, FMC vs. GSP Crop Science).

Admissions by patentees in prior litigations or regulatory filings (e.g., Form 27) can estop them from denying coverage in earlier patents, supporting invalidity claims (Novartis).

Public interest, especially access to affordable drugs for prevalent diseases like diabetes, outweighs patentee rights when a credible challenge exists, and monetary damages suffice when patentees license or import products (AstraZeneca).

Distinctions between “covered,” “claimed,” “disclosed,” or “encompassed” are untenable if the invention is protected by an earlier patent, aligning claims with disclosure (Novartis).

Case Title: Boehringer Ingelheim Pharma GmbH Vs Vee Excel Drugs and Pharmaceuticals Pvt. Ltd.

Date of Order: March 29, 2023

Case No.: CS(COMM) 239/2019

Neutral Citation: 2023:DHC:2272

Name of Court: High Court of Delhi

Name of Judge: Justice Amit Bansal

Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi

Boehringer Ingelheim International GmbH Vs. Eris Lifesciences Limited

Introduction
In the dynamic realm of pharmaceutical innovation, where intellectual property rights safeguard groundbreaking discoveries, the case of Boehringer Ingelheim International GmbH vs. Eris Lifesciences Limited, decided by the High Court of Himachal Pradesh on May 30, 2024, emerges as a pivotal chapter. This dispute, centered on Indian Patent No. 268846 for the drug Empagliflozin, underscores the delicate balance between protecting patent rights and ensuring public access to affordable medicines. Boehringer Ingelheim, a global pharmaceutical titan, sought to restrain Eris Lifesciences, an Indian company, from manufacturing and selling an allegedly infringing product under the brand "Linares-E." The case delves into complex legal questions surrounding patent validity, infringement, and the criteria for granting interim injunctions in patent disputes. By navigating the interplay of Indian patent law, international precedents, and equitable principles, the court’s ruling not only resolves the immediate conflict but also sets a significant precedent for handling patent disputes in India’s commercial courts. This case study offers an in-depth exploration of the factual and procedural nuances, legal issues, parties’ arguments, judicial precedents, the court’s reasoning, and the broader implications of the decision, painting a vivid picture of innovation under legal scrutiny.

Detailed Factual Background
Boehringer Ingelheim International GmbH, a Germany-based pharmaceutical giant, and its Indian subsidiary, Boehringer Ingelheim (India) Pvt. Ltd., are renowned for their contributions to human and veterinary medicine. The plaintiffs hold Indian Patent No. 268846 (IN ‘846), granted on September 18, 2015, for “Glucopyranosyl Substituted Benzenol Derivatives,” a pharmaceutical innovation covering Empagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor used to treat type 2 diabetes mellitus. Empagliflozin, marketed under brand names like Jardiance, Jardiance Duo, and Glyxambi, was introduced in India in 2015 and 2018, achieving significant commercial success. The patent, valid until March 11, 2025, grants Boehringer exclusive rights under Section 48 of the Patents Act, 1970, to prevent unauthorized manufacture, use, sale, or importation of the patented product. Boehringer’s global R&D expenditure, exceeding 3.3 billion Euros in 2020, underscores its commitment to innovation, with Empagliflozin being a cornerstone of its metabolic disease portfolio. The plaintiffs emphasized that no pre-grant or post-grant oppositions were filed against IN ‘846, and the patent is registered in over 70 countries, reinforcing its robustness.

Eris Lifesciences Limited, a publicly listed Indian pharmaceutical company with operations in Himachal Pradesh, Assam, and Gujarat, markets a product under the brand “Linares-E,” containing Empagliflozin and Linagliptin (25 mg/5 mg). Boehringer alleged that this product infringes IN ‘846, as it replicates the patented Empagliflozin formulation without consent. The plaintiffs discovered Linares-E in the market and argued that Eris’s actions constituted a blatant violation of their exclusive patent rights, causing substantial financial harm. They further noted that Eris’s manufacturing and sales activities occurred within the territorial jurisdiction of the Himachal Pradesh High Court, justifying the court’s authority to hear the case. Boehringer highlighted its vigilance in protecting IN ‘846, citing prior successful legal actions against other infringers in courts in Himachal Pradesh, Vadodara, and Dehradun.

Eris, in response, did not dispute manufacturing and selling Linares-E but challenged the validity of IN ‘846, arguing that it lacked inventive step and was vulnerable to revocation. Eris pointed to prior art documents—WO2001027128 (D1, Dapagliflozin Genus) and WO2003099836 (D2, Dapagliflozin Species)—claiming that Empagliflozin was obvious to a person skilled in the art (POSA). Additionally, Eris alleged that Boehringer concealed the revocation of a corresponding patent in China, accusing the plaintiffs of approaching the court with unclean hands. Eris further emphasized the public interest, noting that Linares-E, priced at Rs. 25 per tablet compared to Boehringer’s Rs. 86 per tablet, enhances affordability for diabetic patients, a critical factor given diabetes’s chronic nature.

Detailed Procedural Background
The dispute unfolded through multiple legal filings before the High Court of Himachal Pradesh. Boehringer filed Civil Suit (COMS) No. 09 of 2023 and COMS No. 02 of 2024, seeking a permanent prohibitory injunction to restrain Eris from infringing IN ‘846, alongside other reliefs such as damages. Concurrently, Boehringer filed OMP No. 409 of 2023 under Order XXXIX, Rules 1 and 2, read with Section 151 of the Code of Civil Procedure (CPC), 1908, requesting an interim injunction to halt Eris’s manufacture, sale, and marketing of Linares-E during the suit’s pendency. Eris responded with counterclaims (COMS No. 01 of 2024 in COMS No. 09 of 2023 and COMS No. 07 of 2024 in COMS No. 02 of 2024), challenging the validity of IN ‘846 under Section 64 of the Patents Act, 1970, and opposing the interim injunction.

The court, presided over by Justice Ajay Mohan Goel, reserved the matter on May 3, 2024, and delivered its judgment on May 30, 2024. The plaintiffs were represented by Senior Advocates Ashok Aggarwal and Vinay Kuthiala, supported by a team of advocates, while Eris was represented by Senior Advocate Chander Lall and his legal team. The court’s task was to determine whether Boehringer had established a prima facie case, balance of convenience, and irreparable harm to justify an interim injunction, while also assessing Eris’s claim that IN ‘846 was vulnerable to revocation. The procedural complexity was heightened by Eris’s counterclaims, which sought to leverage prior art and international patent invalidations to undermine the plaintiffs’ case.

Issues Involved in the Case
The case raised several critical legal issues at the intersection of patent law and interim relief:
Whether Boehringer established a prima facie case of patent infringement by demonstrating that Eris’s Linares-E product violated the exclusive rights under IN ‘846.
Whether Eris raised a credible challenge to the validity of IN ‘846, rendering it vulnerable to revocation, thereby negating the plaintiffs’ entitlement to an interim injunction.
Whether the non-disclosure of the revocation of a corresponding patent in China constituted suppression of material facts, affecting Boehringer’s claim to equitable relief.
Whether the balance of convenience favored Boehringer, considering the commercial impact of infringement, or Eris, given the public interest in affordable medicines.
Whether the absence of an interim injunction would cause irreparable harm to Boehringer, or whether monetary damages could adequately compensate any loss.
How the court should weigh public interest arguments, such as access to affordable drugs, against the statutory protections afforded to patentees under the Patents Act, 1970.

These issues required the court to balance the proprietary rights of a patentee against the defendant’s right to challenge patent validity, all while considering equitable principles and public welfare.

Detailed Submission of Parties
Boehringer’s counsel argued that IN ‘846, valid until March 11, 2025, conferred exclusive rights under Section 48 of the Patents Act, 1970, which Eris infringed by manufacturing and selling Linares-E. They emphasized the patent’s registration in 70 countries, its commercial success since 2015, and the absence of pre-grant or post-grant oppositions in India, underscoring its strength. The plaintiffs highlighted Empagliflozin’s technical superiority, with a selectivity for SGLT2 (~2500) surpassing prior art compounds like Dapagliflozin (~1200) and WO’128’s Example 12 (~900), establishing inventive step. They dismissed Eris’s prior art claims, noting that these were examined by patent offices globally without challenging IN ‘846’s validity. On the China revocation, Boehringer clarified that a re-trial petition was pending before China’s Supreme People’s Court, and patent laws vary by jurisdiction, rendering the revocation irrelevant to India. The plaintiffs argued that Eris’s lower pricing was an attempt to exploit Boehringer’s R&D investments, and public interest was safeguarded by the Patents Act’s provisions for compulsory licensing, which Eris had not pursued. Boehringer asserted a prima facie case, balance of convenience, and irreparable harm, citing long-term market damage if infringement continued.

Eris’s counsel countered that IN ‘846 was vulnerable due to lack of inventive step, relying on prior art documents WO2001027128 and WO2003099836, which disclosed Glucopyranosyloxy-Substituted Aromatic Groups as SGLT2 inhibitors. They argued that Empagliflozin was obvious to a POSA, supported by an expert affidavit from Dr. Prabuddha Ganguli. Eris accused Boehringer of concealing the China revocation, claiming this breached the clean hands doctrine, especially since the same prior art underpinned the revocation. On public interest, Eris highlighted Linares-E’s affordability (Rs. 25 vs. Rs. 86 per tablet), arguing that an injunction would disrupt patient access to cost-effective treatment for a chronic condition like diabetes. They contended that Boehringer’s licensing of IN ‘846 to Torrent, Lupin, and Cipla indicated a monetary value, suggesting damages could compensate any loss. Eris asserted that a credible challenge to patent validity negated the need for an injunction, as the court need only find vulnerability at the interim stage, not definitive invalidity.

Detailed Discussion on Judgments Cited by Parties
The court’s analysis was informed by a robust array of Indian and international precedents, shaping its approach to patent validity, interim injunctions, and the clean hands doctrine. The key judgments, their complete citations, and their context in the case are as follows:

M/s Bishwanath Prasad Radhey Shyam vs. Hindustan Metal Industries, (1979) 2 SCC 511: The Supreme Court held that the grant of a patent does not guarantee its validity, which can be challenged in revocation or infringement proceedings, as expressly provided by Section 13(4) of the Patents Act, 1970. The court used this to affirm Eris’s right to challenge IN ‘846’s validity despite its registration.
Dalpat Kumar and Another vs. Prahlad Singh and Others, (1992) 1 SCC 719: The Supreme Court outlined the triple test for interim injunctions—prima facie case, irreparable injury, and balance of convenience—emphasizing that irreparable injury need not be physically irreparable but material, and damages may not suffice. The court applied this to assess Boehringer’s entitlement to relief.
Ten XC Wireless Inc. and Others vs. Mobi Antenna Technologies (Shenzhen) Co. Ltd., 2011 SCC OnLine Del 4648: The Delhi High Court summarized principles for patent injunctions, noting no presumption of validity under Sections 13(4), 64, and 107, and that a credible challenge to validity precludes injunction. The court adopted this to evaluate Eris’s challenge.
Natco Pharma vs. Novartis AG and Anr., FAO(OS) (COMM) 178/2021, decided on 24.04.2024 (Delhi High Court): The Division Bench clarified that there is no statutory presumption of validity, and a defendant need only raise a credible challenge at the interim stage, not prove invalidity. The court used this to set the threshold for Eris’s challenge.
F. Hoffmann-La Roche Ltd. & Anr. vs. Cipla Ltd., ILR 2009 Supp (2) Del 551: The Delhi High Court held that a defendant’s credible challenge to patent validity, raising a serious question, suffices to resist an interim injunction, without requiring a stronger case than the plaintiff. The court relied on this to assess the strength of Eris’s challenge.
UCB Farchim SA vs. Cipla Ltd. & Ors., 2010 SCC OnLine Del 523: The Delhi High Court reiterated that Section 13(4) negates any warranty of validity from pre-grant investigations, supporting the court’s view that IN ‘846’s grant did not presume validity.
Standipack Pvt. Ltd. vs. Oswal Trading Co. Ltd., AIR 2000 Del 23: The Delhi High Court emphasized that patent validity is tested at trial, not interim stages, guiding the court to limit its inquiry to vulnerability.
Bilcare Ltd. vs. Amartara Pvt. Ltd., (2007) 34 PTC 419 (Del): The Delhi High Court underscored the need for a substantial challenge to validity, which the court applied to Eris’s prior art arguments.
Surendra Lal Mahendra vs. Jain Glazers, 1980 SCC OnLine Del 219: The Delhi High Court reinforced that validity challenges are permissible in infringement suits, supporting Eris’s counterclaim.
Beecham Group Ltd. vs. Bristol Laboratories Pty Ltd., (1967-68) 118 CLR 618 (Australia): The Australian High Court held that a defendant alleging invalidity need only show a serious question to be tried, a principle the court adopted for interim relief.
Australian Broadcasting Corporation vs. O’Neill, (2006) 229 ALR 457 (Australia): The Australian High Court reiterated the “serious question” standard, aligning with the court’s approach to Eris’s challenge.
Hexal Australia Pty Ltd. vs. Roche Therapeutics Inc., 66 IPR 325 (Australia): The Australian court held that invalidity at the interim stage requires showing a triable question, which the court used to evaluate Eris’s prior art.
Abbot Laboratories vs. Andrx Pharmaceuticals Inc., No. 05-1433 (U.S. Court of Appeals, Federal Circuit, 22.06.2006): The U.S. court held that vulnerability, not actual invalidity, is the issue at the preliminary injunction stage, requiring less proof than at trial. The court applied this to Eris’s burden.
Helifix Ltd. vs. Blok-Lok Ltd., 208 F.3d 1339 (Fed. Cir. 2000): The U.S. court clarified that a substantial question of invalidity suffices at the interim stage, guiding the court’s analysis.
Erico International Corp. vs. Vutec Corp., No. 2007-1168 (Fed. Cir.): The U.S. court emphasized a substantial question of invalidity to show vulnerability, reinforcing the court’s standard.
Satish Khosla vs. M/s Eli Lilly Ranbaxy Ltd., MANU/DE/0763/1998: The Delhi High Court stressed the clean hands doctrine, requiring full disclosure of material facts, which the court used to assess Boehringer’s non-disclosure of the China revocation.
S.P. Chengalvaraya Naidu vs. Jagannath and Others, MANU/SC/0192/1994: The Supreme Court held that a litigant withholding vital documents to gain advantage commits fraud on the court, informing the court’s clean hands inquiry.
Arunima Baruah vs. Union of India, MANU/SC/7366/2007: The Supreme Court emphasized that suppression of material facts impacts equitable relief, relevant to Boehringer’s conduct.
Charanjit Thukral and Ors. vs. Deepak Thukral and Ors., MANU/DE/1814/2010: The Delhi High Court held that plaintiffs must disclose all material facts, and failure to do so justifies denying injunction, guiding the court’s analysis.
Aura Synergy India Ltd. vs. New Age False Ceiling Co. Pvt. Ltd., 2016 SCC OnLine Del 1109, approved in 2016 SCC OnLine Del 7530-DB: The Delhi High Court held that suppression in IP disputes can preclude injunction, but the court distinguished this due to procedural differences.
FMC Corporation vs. GSP Crop Science Private Limited, 2022 SCC OnLine Del 3784: The Delhi High Court recognized suppression as a ground to challenge injunctions, but the court found it less applicable absent specific rules.
Bayer Healthcare LLC vs. Natco Pharma Limited, 2023 SCC OnLine Del 4458: The Delhi High Court denied an injunction for concealment, but the court noted the absence of similar patent rules in Himachal Pradesh.
Gujarat Bottling Co. Ltd. vs. Coca Cola Co., (1995) 5 SCC 545: The Supreme Court held that equitable relief depends on the plaintiff’s conduct, supporting the court’s clean hands scrutiny.
Freebit AS vs. Bose Corporation, No. 18-2365 (U.S. Court of Appeals, 08.10.2019): The U.S. court invalidated a patent, cited by Eris to argue vulnerability, but the court found it less relevant to India.
Bose Corporation vs. Freebit AS, [2018] EWHC 889 (Pat) (U.K.): The U.K. Patent Court invalidated a patent, but the court deemed it jurisdiction-specific.
Freebit AS vs. Exotic Mile Private Limited, FAO(OS) (COMM) 15/2024 (Delhi High Court, 31.01.2024): The Division Bench upheld denial of injunction due to non-disclosure of international invalidations, but the court distinguished it due to procedural differences.
Wander Ltd. vs. Antox India (P) Ltd., 1990 Supp SCC 727: The Supreme Court held that appellate courts should not interfere with discretionary injunction rulings unless arbitrary, guiding the court’s approach.

These precedents provided a comprehensive framework for evaluating patent vulnerability, interim relief, and equitable conduct.

Detailed Reasoning and Analysis of Judge
Justice Ajay Mohan Goel delivered a nuanced judgment, meticulously applying the triple test for interim injunctions—prima facie case, balance of convenience, and irreparable harm—while addressing Eris’s challenge to IN ‘846’s validity. The court began by acknowledging the undisputed fact of IN ‘846’s registration on September 18, 2015, with an expiry date of March 11, 2025, and Eris’s admission of manufacturing Linares-E without a patent. The absence of pre-grant or post-grant oppositions bolstered Boehringer’s prima facie case, as did the patent’s registration in 70 countries and its commercial success.

On Eris’s vulnerability argument, the court adopted the principles from Bishwanath Prasad and Natco Pharma, recognizing that patent grants carry no presumption of validity under Section 13(4). However, it held that Eris’s reliance on prior art (WO2001027128 and WO2003099836) and the expert affidavit did not sufficiently establish a credible challenge. The court noted Boehringer’s rebuttal that Empagliflozin’s superior selectivity (~2500 vs. ~1200 for Dapagliflozin) demonstrated inventive step, and prior art was considered by global patent offices without undermining IN ‘846. The court, guided by F. Hoffmann-La Roche and Ten XC Wireless, concluded that Eris’s challenge lacked the substantiality required to render the patent vulnerable at the interim stage, as it did not raise a serious question for trial.

The court addressed the China revocation, a cornerstone of Eris’s clean hands argument, by distinguishing Freebit AS and Satish Khosla. Unlike the Delhi High Court, which operates under the Patent Suits Rules, 2022, requiring disclosure of international patent statuses, Himachal Pradesh lacked such rules. The court held that non-disclosure of the China revocation, where a re-trial was pending, was not a material suppression under Order XI, Rule 1 of the CPC, as amended by the Commercial Courts Act, 2015. It emphasized that patent laws are jurisdiction-specific, and invalidation in one country (China) did not inherently affect IN ‘846’s validity in India, especially given its registration in 70 other jurisdictions. The court rejected Eris’s claim that Boehringer’s conduct disentitled it to equitable relief, finding no intent to mislead.

On public interest, the court dismissed Eris’s affordability argument, noting that the Patents Act’s provisions for compulsory licensing (Chapter XVI) and government use (Chapter XVII) address public access in emergencies, which had not been invoked. Citing Gujarat Bottling, the court held that commercial rivals like Eris could not leverage public interest to justify infringement, as this would undermine the statutory framework. The court found the balance of convenience favored Boehringer, given its established market and R&D investments, and that continued infringement would cause irreparable harm by eroding market share and goodwill, which damages could not fully remedy (Dalpat Kumar).

The court concluded that Boehringer satisfied the triple test, while Eris failed to demonstrate IN ‘846’s vulnerability. It granted the interim injunction, restraining Eris from infringing IN ‘846 pending the suit’s resolution, ensuring the plaintiffs’ rights were protected without prejudicing a full trial on validity.

Final Decision
The High Court of Himachal Pradesh allowed OMP No. 409 of 2023 on May 30, 2024, granting an interim injunction. Eris Lifesciences Limited, its directors, licensees, stockists, distributors, and agents were restrained from infringing Indian Patent No. 268846 by manufacturing, advertising, selling, importing, or exporting Empagliflozin in any form, including under the brand “Linares-E,” until the civil suit’s disposal.

Law Settled in this Case
The judgment clarified several principles for patent infringement and interim relief in India:
A registered patent establishes a prima facie case of validity, but defendants may challenge its vulnerability at the interim stage without proving actual invalidity, requiring only a credible, substantial question (Natco Pharma, F. Hoffmann-La Roche).
Non-disclosure of international patent invalidations does not automatically constitute suppression of material facts absent specific procedural rules, and jurisdiction-specific patent laws limit the relevance of foreign revocations (distinguishing Freebit AS).
Public interest arguments, such as drug affordability, cannot override patent rights unless supported by statutory mechanisms like compulsory licensing, as commercial rivals are not entitled to invoke public welfare to justify infringement.
The triple test for interim injunctions—prima facie case, balance of convenience, and irreparable harm—applies rigorously in patent cases, with irreparable harm encompassing long-term market damage beyond monetary compensation (Dalpat Kumar).
In the absence of a credible challenge to patent validity, a patentee with a registered patent and evidence of infringement is entitled to interim protection to preserve its exclusive rights pending trial.

Case Title: Boehringer Ingelheim International GmbH Vs. Eris Lifesciences Limited
ate of Order: May 30, 2024
Case No.: COMS No. 09 of 2023
Neutral Citation: Not provided in the document
Name of Court: High Court of Himachal Pradesh, Shimla
Name of Judge: Justice Ajay Mohan Goel

Disclaimer:The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman,IP Adjutor [Patent and Trademark Attorney] ,High Court of Delhi