Superior metabolic stability, was insufficient to rule out objection under Section 3 (d) of the Patent Act , as it did not explicitly demonstrate therapeutic efficacy
Introduction:
The pharmaceutical industry is a battleground where innovation meets accessibility, and intellectual property rights often clash with public health imperatives. The case of AstraZeneca AB & Ors v. P Kumar & Anr, alongside related suits against T Rao & Anr and Dr. Reddy’s Laboratories Limited, represents a pivotal legal skirmish in India’s patent landscape. At its core, this dispute revolves around AstraZeneca’s efforts to protect its patents for Ticagrelor, a critical antiplatelet drug marketed as Brilinta, against alleged infringement by generic manufacturers. The case, adjudicated by the High Court of Delhi, delves into complex issues of patent validity, evergreening, and the delicate balance between rewarding innovation and ensuring affordable access to life-saving medications. This case study explores the factual and procedural intricacies, the legal arguments advanced by the parties, the judicial reasoning, and the broader implications of the court’s decision.
Detailed Factual Background:
AstraZeneca AB, a global pharmaceutical giant, held three Indian patents related to Ticagrelor: IN 209907 (Species Patent), IN 247984 (Polymorph Patent), and IN 272674 (Formulation Patent). Ticagrelor, an antiplatelet drug, is prescribed to reduce thrombotic events in patients with acute coronary syndrome (ACS), such as heart attacks or unstable angina. Approved in the USA in 2011 and in India in 2012, Ticagrelor is marketed by AstraZeneca under the brand name Brilinta at approximately Rs. 50 per tablet. The plaintiffs claimed that Ticagrelor fell within the scope of IN 907 and IN 984, with its finished formulation covered by IN 674. They asserted that these patents were valid, subsisting, and unchallenged since their publication, except for a revocation petition filed by Micro Labs Limited in 2015, which was pending before the Intellectual Property Appellate Board (IPAB).
The defendants—Micro Labs Ltd., Natco Pharma Ltd., and Dr. Reddy’s Laboratories Ltd.—were accused of planning to launch generic versions of Ticagrelor under brand names such as Bigrelor, an unnamed generic, and Ticaflo, respectively. AstraZeneca alleged that these actions infringed their patents, citing credible market intelligence about the defendants’ imminent launches. The plaintiffs emphasized Ticagrelor’s therapeutic significance, noting that before its introduction, approximately one in three ACS patients faced death, repeat myocardial infarction, or re-hospitalization within six months despite existing treatments. They argued that generic launches would irreparably harm their business and public interest.
The defendants countered that Ticagrelor was disclosed and covered by an earlier patent, IN 241229 (Genus Patent), which expired on July 14, 2018. They alleged that AstraZeneca was engaging in evergreening—extending patent monopolies through subsequent patents without significant therapeutic advancements. The defendants pointed to admissions by AstraZeneca in regulatory filings and foreign litigation, claiming that Ticagrelor was anticipated by IN 229, rendering the suit patents invalid. They also argued that the suit patents lacked novelty, inventive step, and enhanced therapeutic efficacy under Section 3(d) of the Patents Act, 1970, and that AstraZeneca had suppressed material facts about foreign patent revocations.
Detailed Procedural Background:
The case comprised three suits filed by AstraZeneca: CS(COMM) 749/2018 against P Kumar and Micro Labs Ltd., CS(COMM) 792/2018 against T Rao and Natco Pharma Ltd., and CS(COMM) 1023/2018 against Dr. Reddy’s Laboratories Ltd. Each suit included applications for interim injunctions under Order 39 Rules 1 and 2 of the Code of Civil Procedure (CPC) to restrain the defendants from marketing Ticagrelor in violation of AstraZeneca’s patents. Additionally, in CS(COMM) 749/2018, Micro Labs filed an application under Order 39 Rule 4 CPC to vacate the interim orders.
On March 22, 2018, the Delhi High Court granted an ex parte interim injunction in CS(COMM) 749/2018, restraining Micro Labs from selling Ticagrelor. A similar order was passed on April 23, 2018, in CS(COMM) 792/2018 against Natco Pharma, despite the defendants’ initial claim of not having launched the drug. The court noted that Natco had launched the drug during the pendency of the suit. On July 18, 2018, an interim injunction was granted in CS(COMM) 1023/2018 against Dr. Reddy’s. The defendants filed written statements and counterclaims, seeking revocation of the suit patents under Section 64 of the Patents Act, alleging invalidity on grounds of anticipation, obviousness, and non-compliance with statutory requirements.The court consolidated the hearing of the injunction applications (IA Nos. 3986/2018, 4771/2018, 9332/2018) and Micro Labs’ application to vacate the interim orders (IA No. 5096/2018).
Issues Involved in the Case:
The case presented several critical legal and factual issues:
Whether Ticagrelor was disclosed and covered by the expired Genus Patent (IN 229), thereby anticipating the suit patents and rendering them invalid?Whether the suit patents were invalid under Section 3(d) of the Patents Act for being derivatives of a known substance without enhanced therapeutic efficacy?
AstraZeneca’s Submissions:
AstraZeneca argued that the suit patents were valid and infringed by the defendants’ planned generic launches. They contended that IN 229, the Genus Patent, covered 150 quintillion compounds but did not specifically disclose Ticagrelor, which was isolated through the Species Patent (IN 907). They asserted that a person skilled in the art could not have identified Ticagrelor from IN 229’s teachings, negating claims of anticipation under Section 13(1)(a). On prior claiming under Section 13(1)(b), they argued that IN 229 lacked a specific claim to Ticagrelor, making the suit patents novel.
Regarding Section 3(d), AstraZeneca denied that Ticagrelor was a derivative of a known substance from IN 229, arguing that structural similarity alone did not trigger the provision. They relied on an affidavit by Dr. Robert Riley, submitted by Dr. Reddy’s, to claim that Ticagrelor exhibited superior metabolic stability and bioavailability, satisfying the enhanced efficacy requirement if Section 3(d) applied. On Section 8, they admitted revocations of equivalent patents in China and Europe but noted pending appeals with automatic stays and grants in 55-60 countries, asserting substantial compliance.
AstraZeneca emphasized their service to six lakh patients annually and argued that generic launches would cause irreparable harm. They distinguished the Supreme Court’s decision in Novartis AG v. Union of India, claiming it addressed specific disclosure of a known compound, unlike the present case where Ticagrelor was not disclosed in IN 229.
Defendants’ Submissions:
The defendants, represented by Micro Labs, Natco Pharma, and Dr. Reddy’s, argued that the suit patents were invalid as Ticagrelor was disclosed and claimed in IN 229, which expired on July 14, 2018. They relied on AstraZeneca’s admissions in Form 27 filings, where Brilinta and Axcer were declared as working IN 229, and in US litigation against Mylan Inc., where AstraZeneca claimed infringement of US Patent 910 (equivalent to IN 229) by Ticagrelor generics. They contended that these admissions established anticipation and prior claiming, rendering the suit patents invalid under Sections 64(1)(a), (d), (f), and (k).
The defendants accused AstraZeneca of evergreening, arguing that the suit patents were attempts to extend IN 229’s monopoly without significant therapeutic advancements, violating Section 3(d). They highlighted the plaint’s silence on enhanced efficacy and argued that Ticagrelor, being structurally similar to compounds in IN 229, required proof of superior therapeutic efficacy, which was absent. They also alleged non-compliance with Section 8, citing AstraZeneca’s failure to disclose revocations of equivalent patents in China, Europe, and South Korea.
The defendants emphasized public interest, noting that their generics, priced at Rs. 20 per tablet, were significantly cheaper than Brilinta. They argued that the interim injunctions caused irreparable harm to patients and that any loss to AstraZeneca could be compensated monetarily. They relied on judicial precedents, including Novartis AG and F. Hoffmann-La Roche v. Cipla, to assert that a credible challenge to patent validity justified denying interim relief.
Detailed Discussion on Judgments Cited by Parties:
The parties relied on several landmark judgments to bolster their arguments, each addressing specific aspects of patent law. Below is a detailed analysis of these judgments and their context in the case:
Novartis AG v. Union of India, (2013) 6 SCC 1:
The Supreme Court’s decision in Novartis was central to the defendants’ argument on coverage versus disclosure and Section 3(d). The court rejected the appellant’s claim that a patent’s coverage could extend beyond its disclosure, emphasizing that patents grant monopolies in exchange for public disclosure. It held that Section 3(d) sets a higher threshold for pharmaceutical patents, requiring new forms of known substances to demonstrate enhanced therapeutic efficacy. The defendants cited this to argue that IN 229’s coverage of Ticagrelor negated AstraZeneca’s claim of non-disclosure and that the suit patents, as derivatives, failed the efficacy test. AstraZeneca countered that Novartis involved a known compound (Imatinib Mesylate) specifically disclosed in the prior patent, unlike Ticagrelor, which was not disclosed in IN 229. The court found Novartis persuasive, rejecting AstraZeneca’s coverage-disclosure dichotomy and holding that the suit patents prima facie required enhanced efficacy under Section 3(d).
Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries, AIR 1982 SC 1444
Cited by the court, this Supreme Court judgment clarified that novelty and inventive step are mixed questions of law and fact, dependent on circumstances. It outlined tests for obviousness, asking whether the invention was publicly known or would naturally suggest itself to a skilled person. The court applied this to assess whether IN 229 disclosed Ticagrelor, noting that the issue required expert evidence and could not be conclusively determined at the interim stage. This supported the court’s finding that the defendants’ challenge was credible but required trial scrutiny.
F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2009 (40) PTC 125 (Del):
The defendants heavily relied on this Delhi High Court Division Bench decision, which held that a credible challenge to patent validity, particularly under Section 3(d) or Section 64, could deny interim injunctions. The court emphasized full disclosure of patent specifications and related applications in injunction applications. The defendants argued that AstraZeneca’s failure to disclose IN 229’s workings and foreign revocations mirrored the suppression in Roche, justifying vacation of the interim orders. The court agreed, finding AstraZeneca’s omissions material and the defendants’ challenge credible, aligning with Roche’s principles.
F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2015 (225) DLT 391:
Cited by the court on Section 8 compliance, this Division Bench decision clarified that non-compliance with Section 8 is discretionary under Section 64(1)(m), depending on the intent and materiality of the omission. The court found AstraZeneca’s explanations for foreign revocations reasonable, holding that non-disclosure was not material enough to warrant vacating the interim orders, consistent with this judgment.
Bristol-Myers Squibb Company v. J.D. Joshi, 2015 (64) PTC 135 (Del):
The defendants and the court referenced this Delhi High Court decision, which held that challenges under Section 64 are fact-dependent or mixed questions, and a credible challenge to validity can preclude interim relief. The court applied this to find that the defendants’ arguments on anticipation and Section 3(d) raised substantial questions, rendering the suit patents vulnerable.
Merck Sharp & Dohme Corporation v. Glenmark Pharmaceuticals Ltd., 223 (2015) DLT 454:
Cited by the court, this Delhi High Court decision emphasized the reliance on expert testimony in complex pharmaceutical patent disputes, as courts lack technical expertise. The court noted that the issue of Ticagrelor’s disclosure in IN 229 required expert evidence, reinforcing the need for a trial to resolve the dispute.
Chemtura Corporation v. Union of India, 2009 (41) PTC 260 (Del):
The court cited this Delhi High Court decision to outline Section 8’s requirements for disclosing foreign patent applications. It found AstraZeneca’s disclosures sufficient, as they provided reasonable explanations for foreign revocations, aligning with Chemtura’s emphasis on materiality.
Dr. Reddy’s Laboratories (UK) Ltd. v. Eli Lilly & Co. Ltd., [2008] EWHC 2345 (Pat):
AstraZeneca cited this UK High Court decision to argue that a genus patent’s general formula does not disclose specific compounds unless individually described. The court’s finding that a theoretical penumbra of compounds does not negate novelty supported AstraZeneca’s claim that IN 229 did not disclose Ticagrelor. However, the Delhi High Court found this less persuasive in light of AstraZeneca’s admissions and Novartis’s rejection of the coverage-disclosure dichotomy.
Eli Lilly & Company Ltd. v. Apotex Pty Ltd., [2013] FCA 214:
AstraZeneca relied on this Federal Court of Australia decision, which held that selecting a specific compound from a genus patent’s broad class requires significant effort, negating obviousness. AstraZeneca argued that Ticagrelor’s isolation from IN 229’s 150 quintillion compounds was inventive. The court acknowledged this but prioritized AstraZeneca’s admissions and Indian legal standards under Novartis.
Apotex Inc. v. Sanofi-Synthelabo Canada Inc., [2008] 3 SCR 265:
AstraZeneca cited this Supreme Court of Canada decision to defend selection patents, which encourage improvements over genus patents. The court recognized selection patents’ validity but found that AstraZeneca’s admissions and Section 3(d) concerns raised credible challenges, limiting the judgment’s applicability.
Detailed Reasoning and Analysis of Judge:
Justice Jayant Nath’s judgment meticulously analyzed the competing claims, focusing on three key issues: Ticagrelor’s disclosure in IN 229, compliance with Section 3(d), and Section 8 violations. The court’s reasoning was grounded in Indian patent law principles and judicial precedents, balancing the plaintiff’s proprietary rights against the defendants’ public interest arguments.
On the issue of Ticagrelor’s disclosure in IN 229, the court examined AstraZeneca’s admissions in Form 27 filings and US litigation. The identical Form 27 returns for IN 229, IN 907, IN 984, and IN 674, declaring Brilinta and Axcer sales, suggested that AstraZeneca treated Ticagrelor as working all four patents, implying disclosure in IN 229. The US litigation against Mylan Inc., where AstraZeneca claimed infringement of US Patent 910 by Ticagrelor generics, further reinforced this. The court found AstraZeneca’s explanation—that IN 229 was worked through Ticagrelor only after its isolation via IN 907—unconvincing, as the plaint omitted these details. Citing Novartis, the court rejected the coverage-disclosure dichotomy, holding that AstraZeneca’s admissions prima facie indicated that Ticagrelor was anticipated by IN 229, raising a credible challenge under Sections 64(1)(a), (d), (f), and (k).
Regarding Section 3(d), the court noted the plaint’s silence on enhanced therapeutic efficacy, a critical requirement for derivatives of known substances. AstraZeneca’s belated reliance on Dr. Riley’s affidavit, claiming Ticagrelor’s superior metabolic stability, was insufficient, as it did not explicitly demonstrate therapeutic efficacy over IN 229’s compounds. The court applied Novartis and Roche, concluding that the suit patents prima facie failed the Section 3(d) test, as they appeared to be derivatives of IN 229’s compounds without proven efficacy enhancements.
On Section 8, the court accepted AstraZeneca’s explanations for foreign revocations, noting pending appeals and grants in multiple countries. Citing Chemtura and Roche (2015), the court held that the non-disclosure was not material enough to warrant vacating the interim orders, as AstraZeneca substantially complied with statutory requirements.
The court applied the principles from Roche (2009) and Bristol-Myers, emphasizing that a credible challenge to patent validity precludes interim injunctions. The defendants’ arguments on anticipation and Section 3(d) raised substantial questions, rendering the suit patents vulnerable. The court also considered public interest, noting the defendants’ lower-priced generics (Rs. 20 vs. Rs. 50 per tablet) and the expiration of IN 229, which tilted the balance of convenience in their favor. To safeguard AstraZeneca’s interests, the court mandated the defendants to maintain accurate sales accounts.
Final Decision:
On August 8, 2019, The court vacated the interim injunctions granted on March 22, 2018, April 23, 2018, and July 18, 2018, in CS(COMM) 749/2018, CS(COMM) 792/2018, and CS(COMM) 1023/2018, respectively. The court held that AstraZeneca failed to establish a prima facie case, as the defendants raised a credible challenge to the suit patents’ validity under Sections 64(1)(a), (d), (f), (k), and 3(d). The balance of convenience favored the defendants, given the lower price of their generics and IN 229’s expiration. The defendants were directed to maintain quarterly sales accounts, supported by affidavits and authenticated by chartered accountants, to enable potential compensation if AstraZeneca prevailed at trial. The applications were disposed of accordingly.
Law Settled in This Case:
This case reinforces several key principles of Indian patent law:
A credible challenge to patent validity, based on grounds under Section 64 or Section 3(d), is sufficient to deny interim injunctions in infringement suits, as established in F. Hoffmann-La Roche v. Cipla. The coverage-disclosure dichotomy is untenable in India, as per Novartis AG v. Union of India, requiring specific disclosure for patent validity and infringement claims.Section 3(d) imposes a stringent requirement for pharmaceutical patents, mandating proof of enhanced therapeutic efficacy for derivatives of known substances, with silence in the plaint being fatal.Non-compliance with Section 8 is discretionary under Section 64(1)(m), and non-material omissions do not necessarily warrant revocation, as clarified in Chemtura and Roche (2015).Public interest, particularly access to affordable generics, is a significant factor in balancing convenience in patent disputes, especially post-expiration of foundational patents.
Case Title: AstraZeneca AB Vs P Kumar
Date of Order: August 8, 2019
Case No.: CS(COMM) 749/2018
Name of Court: High Court of Delhi at New Delhi
Name of Judge: Hon’ble Mr. Justice Jayant Nath
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
