An International Guide to
Patent Case Management for Judges

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6.5 Patent infringement

The ability to enforce patents is a crucial right for any patentee. Chapter XVIII of the Patents Act, 1970, addresses infringement, forums, remedies, defenses and counterclaims.

6.5.1 Claim construction

Claim construction forms a critical component of patent enforcement and invalidity challenges. Claim construction is a prerequisite for infringement analysis because the claims determine the scope of protection afforded to the patentee. Similarly, only after claims are construed to determine the invention can invalidity analysis proceed. Procedure

Unlike the mechanism of a “Markman” hearing in the U.S., there is no separate procedural step for claim construction. Instead, claim construction is handled as part of the trial. Any disputes concerning the construction of claims will be framed as issues during the case management hearing. In the High Court of Delhi Rules Governing Patent Suits, 2022, it has been recommended that parties file a claim-construction brief before the case management hearing to enable courts and parties to assess whether there are any disputes in relation to the claims.102 Principles

In the context of India’s predecessor legislation, the Supreme Court of India has held that claims must be given an effective meaning and that the specification and claims must be examined and construed together.103 The Supreme Court followed English precedents when coming to this conclusion.

Under the Patents Act, 1970, the Delhi High Court, in F Hoffmann-La Roche Ltd v. Cipla Ltd,104 held that one must undertake a “purposive construction” of the claims. The Delhi High Court drew inspiration from the concept of purposive construction that was formulated in the seminal English judgment Catnic Components Ltd v. Hill and Smith Ltd105 This principle is captured in the following two dicta in the Catnic Components case:

whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.

No plausible reason has been advanced why any rational patentee should want to place so narrow a limitation on his invention. On the contrary, to do so would render his monopoly for practical purposes worthless, since any imitator could avoid it and take all the benefit of the invention by the simple expedient of positioning the back plate a degree or two from the exact vertical.106

This principle of purposive construction was streamlined in the form of “Improver” questions in a subsequent judgment in the United Kingdom (U.K.)107 and later approved by the House of Lords.108 However, the U.K. Supreme Court, in Actavis UK Ltd v. Eli Lilly and Co.,109 disagreed with the earlier line of cases. According to the U.K. Supreme Court, this earlier line of case law on purposive construction conflated the issue of claim construction and infringement analysis.

The current standard in the U.K. requires a court to adopt a “normal interpretation” approach. For infringement purposes, according to the U.K. Supreme Court, one must examine whether the infringing device or process infringes the claim as construed by such normal interpretation. If not, the U.K. Supreme Court dictates that a court must thereafter assess whether the claim is infringed by equivalents. It has formulated a test for assessing such equivalents. The U.K. Supreme Court’s judgments in Actavis UK Ltd and subsequently in Icescape Ltd v. Ice-World International BV 110 have clarified that the normal interpretation of claims is also purposive. Such interpretations are purposive because courts are to construe claims as per their ordinary language, in their context (description and drawings) and in the light of the factual background (common general knowledge in the art).

There has been no subsequent judgment in India addressing these jurisprudential developments. However, since even the earlier rulings of the Supreme Court of India and the Delhi High Court were guided by the English precedents, it is expected that Indian courts will take a similar approach to claim construction.

6.5.2 Infringement analysis What is “infringement”?

The Patents Act, 1970, does not separately define “infringement,” but courts regard any violation of the rights accorded under Section 48 of the Act as an infringement. Like most international jurisdictions, and consistent with Article 28 of the TRIPS Agreement, Section 48 of the Act confers an exclusive right on the patentee to prevent third parties from “making, using, offering for sale, selling or importing for those purposes” the patented product.111 In the case of process patents, the patentee has the exclusive right to prevent third parties from using the process and from “using, offering for sale, selling or importing for those purposes” the “product obtained directly by the patented process.”112 Committing these acts without the patentee’s consent constitutes infringement. Exports as infringement

The Delhi High Court has held that the term “sale,” in the context of another provision of the Patents Act, 1970, includes “exports.”113 The Delhi High Court has also recently granted an interim injunction because exports from India would have also amounted to use in India.114 Proving infringement

A plaintiff must compare the alleged infringing product or process with the granted claim or claims to prove infringement.115 Claim construction precedes this exercise of comparison.116

The Patents Act, 1970, is silent on the doctrine of equivalence and other analogous concepts. The predecessor legislation allowed patentees to sue for infringement even when the infringers counterfeited or imitated the invention.117 Case law under the predecessor legislation suggested that courts would ignore “trifling or unessential variation.”118 Defendants were guilty of infringement if they made “what is in substance the equivalent of the patented article.”119 Case law under the current Act suggests that a similar approach may be followed.120

6.5.3 Defenses to infringement

The rights under Section 48 of the Patents Act, 1970, are expressly subject to other provisions of the Act. Section 107(1) states that all the grounds for revoking a patent for invalidity can be used as defenses to a claim for patent infringement. Defendants can, thus, contest the suit patent’s validity even without filing a counterclaim.

Section 107A recognizes the Bolar exception for defendants to use the patented product or process for developing information for regulatory filings both in India and abroad. The Delhi High Court’s judgment in Bayer Corp. v. Union of India121 carries a detailed discussion of the Bolar exception.

India follows the rule of international exhaustion regarding patents. Under Section 107A(b) of the Act, importing a duly authorized product from a foreign jurisdiction is not an infringement. Thus, the position is similar to that under the Trade Marks Act, 1999,122 but different from the domestic exhaustion rule followed under the Indian Copyright Act, 1957.123

Section 107(2), read with Section 47, contains well-known exclusions from the scope of a patent’s exclusivity, such as the research exemption, educational use and governmental use.

6.5.4 Counterclaim of invalidity

Defendants invariably file a counterclaim seeking revocation under Section 64(1) of the Patents Act, 1970. The grounds provided for revocation under Section 64(1) are exhaustive. There is a view that courts retain the discretion not to revoke a patent despite the fulfillment of one or more of the grounds under Section 64(1),124 though this does not seem to be the correct position in law. Proving any one of the grounds under Section 64(1) ought to lead to revocation of the patent.

The grounds for revocation usually taken in a counterclaim include lack of novelty or inventive step and non-patentable subject matter. It is also usual for defendants to support the grounds for revocation, especially in respect of lack of novelty and inventive step, by relying upon claims granted in other jurisdictions. If, in any other foreign jurisdiction, claims granted in corresponding patents are narrower than those granted in India, it is common for defendants in India to question the validity of the Indian patent by referring to such claims. Thus, it is advisable for patentee-plaintiffs in infringement actions in India to check whether the scope of claims in other significant jurisdictions differs, at least broadly, from that of the claims in India. If the patentee narrows the claims in other jurisdictions, it is advisable to make similarly narrower claims in India at the prosecution stage.

The citing of corresponding claims from foreign jurisdictions relates to the concept of “file-wrapper estoppel.” Although patent rights are strictly territorial, defendants argue that the patentee ought to be bound by statements, concessions and amendments made by the patentee before foreign patent offices concerning the same invention. Usually, such narrowing amendments in foreign jurisdictions, without corresponding Indian amendments, could adversely impact the grant of interim relief.

Another ground that defendants often rely upon is noncompliance with Section 8 obligations. Section 8(1) of the Act requires mandatory disclosure of the details of all corresponding foreign applications. Section 8(2) requires the filing of the prosecution history of corresponding foreign applications if so directed by the Indian Patent Office.

An issue frequently agitated in Indian courts, in invalidity challenges to pharmaceutical patents, concerns coverage and disclosure. In Novartis AG v. Union of India,125 the Supreme Court held that a patentee cannot contend that a patent’s coverage is more expansive than its disclosure. The following observation by Justice Jacob in the English case of European Central Bank v. Document Security Systems Inc. is often cited in the Indian context:

Professor Mario Franzosi likens a patentee to an Angora cat. When validity is challenged, the patentee says his patent is very small: the cat with its fur smoothed down, cuddly and sleepy. But when the patentee goes on the attack, the fur bristles, the cat is twice the size with teeth bared and eyes ablaze.126

Since claims are granted only upon an enabling disclosure, courts must presume that a prior patent discloses the claimed subject matter in an enabling manner. However, there have been various opinions expressed that the patent coverage could be wider than the disclosure, leading to multiple patents thereafter. The Delhi High Court has recently considered this issue in a series of interim orders, wherein the preponderance of the view favored the interpretation in Novartis.127 This view is presently the prevalent one.