A) ABSTRACT / HEADNOTE

The decision in AstraZeneca AB & Anr. v. Intas Pharmaceuticals Limited & Ors., decided on 20 July 2021 by the Delhi High Court, concerns denial of interim injunction in patent infringement suits involving the drug Dapagliflozin (DAPA). The appellants relied on two Indian patents: IN 205147, a genus patent based on a Markush structure, and IN 235625, a species patent specifically claiming DAPA. The central controversy was whether DAPA was disclosed in the earlier genus patent and whether the later species patent was vulnerable on grounds of prior disclosure, obviousness, double patenting, and non-compliance with Section 8 of the Patents Act, 1970.

The Court examined the doctrine of coverage versus disclosure, obviousness standards, Section 8 obligations, and principles governing interim injunction in patent disputes. It held that when a patentee claims infringement of two patents over the same product, it raises a serious question regarding validity. The Court emphasized that patent rights are statutory monopolies and must strictly comply with statutory conditions. It concluded that the defendants had raised a credible challenge to validity, especially regarding obviousness and potential double patenting, and thus refused interim relief.

The judgment reflects judicial caution against evergreening and underscores the principle that only one patent can subsist for one invention.

Keywords: Patent Infringement; Genus and Species Patent; Dapagliflozin; Obviousness; Double Patenting; Section 8 Compliance; Interim Injunction; Evergreening.

B) CASE DETAILS

i) Judgement Cause Title: AstraZeneca AB & Anr. v. Intas Pharmaceuticals Limited & Ors.

ii) Case Number: FAO(OS)(COMM) 139/2020 and connected appeals

iii) Judgement Date: 20 July 2021

iv) Court: High Court of Delhi

v) Quorum: Hon’ble Mr. Justice Rajiv Sahai Endlaw and Hon’ble Mr. Justice Amit Bansal

vi) Author: Justice Rajiv Sahai Endlaw

vii) Citation: 2021 SCC OnLine Del 3417

viii) Legal Provisions Involved:
Sections 2(j), 2(ja), 2(l), 3(d), 8, 11A, 13(4), 48 of the Patents Act, 1970;
Order XLIII Rule 1(r) of CPC;
Section 13(1A) of Commercial Courts Act, 2015.

ix) Judgments overruled by the Case: None expressly overruled.

x) Law Subjects: Intellectual Property Law; Patent Law; Commercial Law; Civil Procedure.

C) INTRODUCTION AND BACKGROUND OF JUDGEMENT

The appeals arose from denial of interim injunction in multiple suits filed by AstraZeneca against generic pharmaceutical companies. The suits alleged infringement of two patents covering Dapagliflozin, a drug for Type-II diabetes. The first patent, IN 205147, was a genus patent claiming a Markush formula. The second patent, IN 235625, was a species patent specifically claiming DAPA.

The genus patent expired in October 2020. The species patent was valid till May 2023. The plaintiffs claimed that DAPA was not disclosed in the genus patent and was independently invented later. The defendants argued that DAPA was covered and disclosed in the earlier patent and that the second patent was invalid for double patenting and obviousness.

The Commercial Division refused interim injunction. The plaintiffs appealed. The Division Bench examined whether a patentee could claim infringement of two patents over the same product. The Court’s reasoning focused on statutory interpretation and principles against evergreening.

D) FACTS OF THE CASE

The appellants held Indian Patent No. 205147, granted in 2007 and expiring in 2020. It covered a class of C-aryl glucosides using a Markush structure. Later, they obtained Indian Patent No. 235625, granted in 2009 and expiring in 2023, specifically claiming Dapagliflozin.

The appellants marketed DAPA under brand names after regulatory approval. Generic manufacturers began marketing DAPA upon expiry of the genus patent. The appellants filed infringement suits asserting violation of both patents.

The defendants contended that DAPA was disclosed in the genus patent. They relied on admissions made before the US Patent Office. They also cited alleged non-disclosure under Section 8 of the Patents Act regarding foreign prosecution history.

The Single Judges refused interim injunction on grounds of credible challenge to validity. The plaintiffs appealed. The Division Bench evaluated whether interim relief was justified under settled principles in Wander Ltd. v. Antox India (P) Ltd., 1990 Supp SCC 727.

E) LEGAL ISSUES RAISED

i. Whether Dapagliflozin was disclosed in the earlier genus patent.

ii. Whether the species patent was vulnerable to revocation for obviousness.

iii. Whether claiming infringement of both patents implied admission of double patenting.

iv. Whether non-compliance with Section 8 rendered the patent vulnerable.

v. Whether interim injunction was justified when validity faced credible challenge.

F) PETITIONER / APPELLANT’S ARGUMENTS

The counsels for Appellants submitted that IN 147 was a genus patent. It disclosed millions of compounds. DAPA was not specifically disclosed. It was only covered.

They relied on distinction between coverage and disclosure. They cited Novartis AG v. Union of India, (2013) 6 SCC 1, arguing that coverage does not equal disclosure. They argued DAPA was invented later through research. It involved technical advancement.

They submitted that IN 625 was examined and granted after scrutiny. It enjoyed presumption of validity. They emphasized global patent grants in over 70 countries. They denied evergreening.

They argued non-disclosure under Section 8 was unintentional. They contended foreign prosecution objections were irrelevant. They submitted balance of convenience favored them due to investment in R&D.

G) RESPONDENT’S ARGUMENTS

The counsels for Respondents submitted that plaintiffs admitted DAPA was covered under IN 147. Thus DAPA was disclosed earlier.

They relied on pleadings and US litigation admissions. They argued that agreeing to terminal disclaimer in US showed double patenting.

They invoked Section 3(d) principles from Novartis. They argued no technical advancement was shown. Substitution of methoxy with ethoxy was obvious.

They argued credible challenge sufficed at interim stage. They cited F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2015 (225) DLT 391, emphasizing obviousness analysis.

They stressed public interest due to price difference.

H) RELATED LEGAL PROVISIONS

i. Section 2(j) defines invention. It requires novelty and inventive step.

ii. Section 2(ja) defines inventive step. It demands technical advance or economic significance.

iii. Section 3(d) prevents patenting of new forms without enhanced efficacy.

iv. Section 8 mandates disclosure of foreign filings. Non-compliance may lead to revocation.

v. Section 48 confers exclusive rights during patent term.

The Court interpreted these provisions strictly. Patent rights exist only within statutory limits.

I) PRECEDENTS ANALYSED BY COURT

i. The Court referred to Novartis AG v. Union of India, (2013) 6 SCC 1. The Supreme Court held enhanced efficacy must be proven for pharmaceutical derivatives. It discouraged evergreening.

ii. The Court relied on Wander Ltd. v. Antox India (P) Ltd., 1990 Supp SCC 727. It limited appellate interference in interim orders.

iii. It considered F. Hoffmann-La Roche Ltd. v. Cipla Ltd.. The Delhi High Court discussed obviousness and credible challenge standard.

These precedents guided refusal of injunction where validity faced serious doubt.

J) JUDGEMENT

a. RATIO DECIDENDI

i. The Court held one invention can have only one patent.

ii. By alleging infringement of both patents, plaintiffs admitted DAPA was subject of both.

iii. Patent rights are statutory monopolies. They must strictly comply with statute.

iv. A credible challenge to validity defeats interim injunction.

v. Species patent appeared vulnerable to obviousness and possible double patenting.

vi. Public interest favored cheaper generics.

The Court dismissed appeals. Interim injunction was refused. Directions to maintain accounts were continued.

b. OBITER DICTA

i. The Court observed suspicion of evergreening.

ii. It emphasized legislative intent limiting patent term.

iii. It remarked that delays in regulatory approval cannot justify extended monopoly.

c. GUIDELINES

i. Interim injunction in patent cases requires strong prima facie validity.

ii. Credible challenge suffices to deny relief.

iii. Patentee must strictly comply with Section 8.

iv. Double patenting concerns will be closely examined.

v. Courts must guard against evergreening.

K) CONCLUSION & COMMENTS

The judgment reinforces strict scrutiny in pharmaceutical patent litigation. It discourages strategic layering of genus and species patents without demonstrable technical advancement. It aligns with Novartis principles against evergreening.

The Court balanced innovation incentives with public access. It applied statutory interpretation rigorously. It reaffirmed that interim injunction is discretionary and dependent on clear prima facie validity.

L) REFERENCES

a. Important Cases Referred

i. Novartis AG v. Union of India, (2013) 6 SCC 1.
ii. Wander Ltd. v. Antox India (P) Ltd., 1990 Supp SCC 727.
iii. F. Hoffmann-La Roche Ltd. v. Cipla Ltd., 2015 (225) DLT 391.

b. Important Statutes Referred

i. Patents Act, 1970.
ii. Commercial Courts Act, 2015.
iii. Code of Civil Procedure, 1908