Introduction
In the high-stakes world of pharmaceutical patents, where innovation meets commerce, disputes over intellectual property rights often determine access to life-saving drugs. The case of AstraZeneca AB & Ors. v. P. Kumar & Anr., along with related suits against T. Rao & Anr. and Dr. Reddy’s Laboratories Ltd., decided by the Delhi High Court on August 8, 2019, epitomizes such a battle. At its core, this litigation involves AstraZeneca’s attempt to protect its patents for TICAGRELOR, a critical antiplatelet drug marketed as BRILINTA, against alleged infringement by Indian generic manufacturers Micro Labs Ltd., Natco Pharma Ltd., and Dr. Reddy’s Laboratories Ltd. The plaintiffs sought interim injunctions to restrain the defendants from launching generic versions, claiming infringement of three patents: IN 209907 (Species Patent), IN 247984 (Polymorph Patent), and IN 272674 (Formulation Patent). The defendants countered with a robust challenge, alleging that TICAGRELOR was disclosed in an expired genus patent (IN 241229), rendering the suit patents invalid due to anticipation, lack of inventive step, and evergreening under Section 3(d) of the Patents Act, 1970. This case study delves into the intricate factual and legal landscape, the parties’ submissions, judicial precedents, and the court’s reasoning, culminating in a decision that underscores the vulnerability of pharmaceutical patents to credible challenges and the balance between innovation and public access to affordable medicine.
Detailed Factual Background
AstraZeneca AB, a Swedish pharmaceutical giant, along with its affiliates, holds three Indian patents related to TICAGRELOR, an antiplatelet drug used to prevent thrombotic events in patients with acute coronary syndrome (ACS), such as heart attacks or strokes. TICAGRELOR, with the international non-proprietary name (INN) and IUPAC designation (1S,2S,3R,5S)-3-[7-[(1R,2S)-2-(3,4-Difluorophenyl)cyclopropylamino]-5-(propylthio)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl]-5-(2-hydroxyethoxy)cyclopentane-1,2-diol, has an empirical formula of C23H28F2N6O4S and a molecular weight of 522.57. The drug, marketed globally as BRILINTA and in India as BRILINTA and AXCER, received regulatory approval in India in May 2012 and was commercially launched in October 2012 at ₹50 per tablet. TICAGRELOR’s significance lies in its ability to reduce the risk of cardiovascular events in ACS patients, addressing a gap where one in three patients previously faced death, repeat myocardial infarction, or re-hospitalization within six months despite existing treatments.
The three patents at issue are: IN 209907 (Species Patent), granted on September 11, 2007, covering TICAGRELOR as a specific compound within a Markush formula and detailing its synthesis process; IN 247984 (Polymorph Patent), covering four crystalline forms of TICAGRELOR; and IN 272674 (Formulation Patent), covering TICAGRELOR’s pharmaceutical composition. AstraZeneca asserted that these patents, valid and subsisting, grant exclusive rights under Section 48 of the Patents Act to prevent others from making, using, selling, or importing TICAGRELOR or its claimed forms. The Species Patent, published in 2005, faced no pre-grant or post-grant oppositions, though Micro Labs filed a revocation petition in 2015, pending before the Intellectual Property Appellate Board (IPAB).
The defendants—Micro Labs Ltd., Natco Pharma Ltd., and Dr. Reddy’s Laboratories Ltd.—are Indian generic manufacturers planning to launch TICAGRELOR under names like BIGRELOR, an unnamed generic, and TICAFLO, respectively. AstraZeneca received market intelligence in March and April 2018 indicating imminent launches by Micro Labs (early April 2018) and Natco (third week of April 2018), with Micro Labs allegedly promoting to doctors and preparing packaging. For Dr. Reddy’s, AstraZeneca learned in July 2018 of plans for a full commercial launch, supported by a manufacturing license and offers to business partners. The defendants denied current commercialization but admitted to preparatory activities, with Dr. Reddy’s actively selling TICAFLO.
A critical contention was the defendants’ reliance on an expired genus patent, IN 241229 (granted June 24, 2010, expired July 14, 2018), which they claimed disclosed TICAGRELOR. AstraZeneca admitted IN 229 generically covered TICAGRELOR among 150 quintillion (1.5 × 10^20) compounds but argued it lacked specific disclosure, requiring the inventive step of IN 907 to isolate TICAGRELOR. The defendants cited AstraZeneca’s Form 27 filings, which reported BRILINTA and AXCER sales under IN 229, and U.S. litigation asserting infringement of US 910 (IN 229’s equivalent) by TICAGRELOR generics, as admissions of disclosure. They further alleged evergreening, claiming the suit patents extended IN 229’s monopoly without enhanced therapeutic efficacy, violating Section 3(d). Additional defenses included invalidity due to anticipation, obviousness, and non-compliance with Section 8’s disclosure requirements, citing foreign patent revocations.
Detailed Procedural Background
AstraZeneca filed three suits in the Delhi High Court: 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 sought a permanent injunction to restrain the defendants from infringing IN 907, IN 984, and IN 674 by marketing TICAGRELOR generics, alongside damages and other reliefs. Concurrently, AstraZeneca filed interim injunction applications under Order 39 Rules 1 and 2 of the Code of Civil Procedure, 1908: IA No. 3986/2018 in CS(COMM) 749/2018, IA No. 4771/2018 in CS(COMM) 792/2018, and IA No. 9332/2018 in CS(COMM) 1023/2018. Micro Labs also filed IA No. 5096/2018 under Order 39 Rule 4 to vacate the interim order in CS(COMM) 749/2018.
The court granted ex parte interim injunctions: on March 22, 2018, in CS(COMM) 749/2018, restraining Micro Labs from selling TICAGRELOR; on April 23, 2018, in CS(COMM) 792/2018, noting Natco’s launch during pendency; and on July 18, 2018, in CS(COMM) 1023/2018 against Dr. Reddy’s. The defendants filed written statements, with Natco and Micro Labs also lodging counter-claims for revocation of the suit patents, citing grounds under Section 64, including anticipation by IN 229, lack of inventive step, and Section 3(d) violations. Extensive hearings before Justice Jayant Nath involved detailed submissions, with AstraZeneca seeking to confirm the injunctions and the defendants urging their vacation based on the patents’ vulnerability.
Issues Involved in the Case
The primary issue was whether AstraZeneca was entitled to interim injunctions to restrain the defendants from marketing TICAGRELOR generics, alleging infringement of IN 907, IN 984, and IN 674. This hinged on whether the defendants raised a credible challenge to the patents’ validity, rendering them vulnerable under Section 64 of the Patents Act. Sub-issues included whether TICAGRELOR was disclosed in the expired IN 229, negating novelty and inventive step under Sections 64(1)(a), (d), (f), and (k); whether the suit patents constituted evergreening under Section 3(d) by lacking enhanced therapeutic efficacy; and whether AstraZeneca’s non-disclosure of foreign patent revocations violated Section 8, warranting revocation under Section 64(1)(m). The court also considered whether AstraZeneca’s Form 27 filings and U.S. litigation constituted admissions that IN 229 disclosed TICAGRELOR, and whether the balance of convenience and irreparable harm favored maintaining the injunctions.
Detailed Submission of Parties
AstraZeneca argued that the suit patents were valid, subsisting, and infringed by the defendants’ planned or actual TICAGRELOR sales. They asserted that IN 907 specifically claimed TICAGRELOR, selected from 150 quintillion compounds in IN 229’s Markush formula, requiring an inventive step unachievable by a skilled artisan based on IN 229’s generic disclosure. They denied anticipation, arguing IN 229’s publication post-dated IN 907’s priority date (December 4, 1998 vs. February 2, 1999), and lacked specific TICAGRELOR disclosure. On prior claiming under Section 13(1)(b), they contended IN 229’s broad claims did not individually claim TICAGRELOR. Regarding Section 3(d), AstraZeneca argued TICAGRELOR was not a derivative of a known IN 229 compound, and even if applicable, Dr. Robert Riley’s affidavit (filed by Dr. Reddy’s) demonstrated TICAGRELOR’s superior metabolic stability and bioavailability. They addressed Section 8, admitting revocations of IN 907 and IN 984 equivalents in China and Europe but noting pending appeals with automatic stays and grants in 57, 55, and 60 countries for IN 907, IN 984, and IN 674, respectively, claiming substantial compliance. AstraZeneca refuted evergreening, arguing Form 27 filings showed IN 229 was worked through TICAGRELOR post-isolation via IN 907, not that IN 229 disclosed it, and U.S. litigation aligned with broader U.S. infringement standards. They emphasized servicing 600,000 patients annually, justifying injunctions to protect their market and public interest.
The defendants—Micro Labs, Natco, and Dr. Reddy’s—presented largely aligned defenses, asserting the suit patents’ invalidity. They argued IN 229 disclosed TICAGRELOR through claims 1, 2–7, and substitutions detailed in its specification, supported by AstraZeneca’s Form 27 filings listing BRILINTA and AXCER under IN 229 and U.S. litigation claiming US 910 (IN 229 equivalent) covered TICAGRELOR. They alleged evergreening, claiming the suit patents extended IN 229’s monopoly post-expiry (July 14, 2018) without inventive step or enhanced efficacy under Section 3(d), as the plaint lacked efficacy pleadings. They invoked Sections 64(1)(a), (d), (f), and (k), arguing IN 907 was anticipated by IN 229, obvious to a skilled artisan, and not an invention. On Section 8, they highlighted suppressed revocations of IN 907 in China, IN 984 in Europe, China, and South Korea, and IN 674’s refusal in China, alleging non-compliance. Micro Labs noted its 2015 IPAB revocation petitions as pre-existing challenges, while Natco criticized AstraZeneca’s impleadment of individuals (P. Kumar, T. Rao) to obscure corporate defendants. Dr. Reddy’s emphasized TICAFLO’s reliance on the public-domain IN 229 and cited Novartis AG v. UOI to reject the coverage-disclosure dichotomy. The defendants argued generics at ₹20 per tablet (vs. ₹50 for BRILINTA) served public interest, and any harm to AstraZeneca was compensable, tilting the balance of convenience against injunctions.
Detailed Discussion on Judgments Cited by Parties
AstraZeneca relied on Dr. Reddy’s Laboratories (UK) Ltd. v. Eli Lilly & Co. Ltd., [2008] EWHC 2345 (Pat), where the UK High Court held that a genus patent’s general formula does not destroy novelty of a specific compound unless disclosed in individualized form, supporting their claim that IN 229’s broad Markush formula did not disclose TICAGRELOR. In Eli Lilly & Company Ltd. v. Apotex Pty Ltd., [2013] FCA 214, the Federal Court of Australia rejected the notion that a skilled artisan could easily derive a specific compound (olanzapine) from a genus patent’s vast compound class, reinforcing AstraZeneca’s argument against obviousness. Apotex Inc. v. Sanofi-Synthelabo Canada Inc., [2008] 3 S.C.R. 265, from the Supreme Court of Canada, upheld selection patents as encouraging improvements over genus patents, countering evergreening concerns by noting selection patents may be sought by third parties and apply beyond pharmaceuticals.
The defendants heavily relied on Novartis AG v. Union of India, (2013) 6 SCC 1, where the Supreme Court rejected the distinction between patent coverage and disclosure, holding that a patent’s monopoly depends on enabling disclosure, not broad claims. The court’s disapproval of a coverage-disclosure gap undermined AstraZeneca’s claim that IN 229 covered but did not disclose TICAGRELOR, and its strict interpretation of Section 3(d) supported the defendants’ evergreening argument. F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2009 (40) PTC 125 (Del), a Delhi High Court Division Bench decision, established that a credible challenge to patent validity, especially under Section 3(d), justifies denying interim injunctions, bolstering the defendants’ case. Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries, AIR 1982 SC 1444, clarified that novelty and inventive step are mixed questions of law and fact, requiring expert evidence, supporting the defendants’ call for trial. Merck Sharp & Dohme Corporation v. Glenmark Pharmaceuticals Ltd., 223 (2015) DLT 454, emphasized courts’ reliance on expert testimony in technical patent disputes, aligning with the defendants’ stance that TICAGRELOR’s disclosure required factual inquiry. Bristol-Myers Squibb Company v. J.D. Joshi, 2015 (64) PTC 135 (Del), noted that Section 64 challenges involve fact-dependent questions, justifying the defendants’ demand for evidence. Chemtura Corporation v. Union of India, 2009 (41) PTC 260 (Del), and F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2015 (225) DLT 391, clarified Section 8’s discretionary revocation, supporting AstraZeneca’s compliance claim but not overriding the defendants’ validity challenges.
Detailed Reasoning and Analysis of Judge
Justice Jayant Nath’s analysis focused on three key issues: whether TICAGRELOR was disclosed in IN 229, whether the suit patents violated Section 3(d), and whether Section 8 non-compliance warranted vacating the injunctions. On the first issue, the court examined whether IN 229’s disclosure negated the suit patents’ novelty and inventive step. AstraZeneca argued IN 229’s vast compound class (150 quintillion) lacked specific TICAGRELOR disclosure, while the defendants claimed claims 1, 2–7, and substitutions enabled derivation. The court, citing Bishwanath Prasad and Merck Sharp & Dohme, noted that novelty and inventive step are mixed questions requiring expert evidence, unavailable at this stage. However, it heavily weighed AstraZeneca’s Form 27 filings (2014–2018), identically reporting BRILINTA and AXCER sales under IN 229, IN 907, IN 984, and IN 674, and U.S. litigation asserting US 910’s infringement by TICAGRELOR generics. These “admissions” suggested IN 229 disclosed TICAGRELOR, and AstraZeneca’s explanation—that IN 229 was worked through TICAGRELOR post-IN 907 isolation—was absent from the plaint, constituting suppression of material facts per F. Hoffmann-La Roche (2009). The court rejected AstraZeneca’s coverage-disclosure distinction, citing Novartis, which negated broad claims without enabling disclosure, finding a prima facie case that IN 229 disclosed TICAGRELOR.
On Section 3(d), the defendants argued TICAGRELOR was a derivative of IN 229 compounds, requiring enhanced therapeutic efficacy, absent in the plaint. AstraZeneca denied TICAGRELOR was a derivative, citing structural differences, and belatedly relied on Dr. Robert Riley’s affidavit, claiming superior metabolic stability. The court, referencing Novartis and F. Hoffmann-La Roche (2009), held that Section 3(d) demands strict therapeutic efficacy proof for derivatives. The plaint’s silence and Riley’s affidavit, which noted both IN 229 and IN 907 compounds inhibit platelet aggregation with IN 907’s advantages (lower dose, stability) not clearly tied to therapeutic efficacy, failed to meet this standard. The court found a prima facie Section 3(d) violation, rendering the patents vulnerable.
On Section 8, the defendants alleged suppression of foreign revocations (IN 907 in China, IN 984 in Europe, China, South Korea). AstraZeneca countered with pending appeals and grants in 55–60 countries. Citing Chemtura and F. Hoffmann-La Roche (2015), the court found substantial compliance, as the omissions were not material enough to vacate the injunctions. However, the strong validity challenges under Sections 64(1)(a), (d), (f), (k), and 3(d), supported by F. Hoffmann-La Roche (2009) and Bristol-Myers Squibb, led the court to conclude the defendants raised a credible challenge. The balance of convenience favored the defendants, given IN 229’s expiry, generics’ lower price (₹20 vs. ₹50), and compensable harm to AstraZeneca, outweighing potential market loss.
Final Decision
On August 8, 2019, the Delhi High Court vacated the interim injunctions in IA Nos. 3986/2018, 4771/2018, 9332/2018, and 5096/2018, allowing the defendants to market TICAGRELOR generics. The court directed the defendants to maintain accurate sales accounts, file quarterly affidavits verified by a director, and submit chartered accountant-authenticated statements. The applications were disposed of, with the suits listed for further proceedings.
Law Settled in This Case
The case clarified several patent law principles. It reinforced that a credible challenge to patent validity, particularly under Sections 64(1)(a), (d), (f), (k), and 3(d), can defeat interim injunctions, emphasizing vulnerability over definitive invalidity at the interim stage. The court affirmed Novartis’ rejection of the coverage-disclosure dichotomy, requiring enabling disclosure for monopoly claims, impacting genus-species patent disputes. Section 3(d)’s strict therapeutic efficacy requirement for derivatives was upheld, with silence in pleadings fatal to patent holders. The decision underscored the necessity of full disclosure in plaints, including prior patents and admissions, per F. Hoffmann-La Roche (2009). On Section 8, discretionary revocation was clarified, requiring material non-disclosure. The case balanced innovation with public interest, prioritizing affordable generics when validity is credibly challenged, especially post-expiry of a genus patent.
Case Title:AstraZeneca AB Vs. P. KumarDate of Order:August 8, 2019
Case No.CS(COMM) 749/2018,
Name of Court:High Court of Delhi
Name of Judge:Jayant Nath, J.
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Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
