Drafting Without Borders: Patent Claim Pitfalls in International Protection

Introduction : The claim defines the patent. The specification and drawings describe the invention, but the claims are the boundaries of the legal protection conferred by a patent.

The patentee, however, rarely operates in one jurisdiction. A single PCT application can involve more than 150 national phases, each of which evaluates the claim in light of its own particular criteria relating to patentability and remedies. A generic error in the specification, be it an overreaching claim or a carelessly drafted Markush group, is replicated in every national phase and usually has adverse consequences for the patentee. The following errors, on the other hand, are entirely avoidable, which makes their persistent occurrence even more frustrating:

1. Overly broad claims with insufficient disclosure of the invention;
2. Claim language that presumes uniform patentability of subject matter across jurisdictions, such as treatment methods;
3. Added matter in the claim amendment process, particularly in the prosecution before the EPO and USPTO;
4. Prosecution history estoppel in the interpretation of claim language;
5. Unity of invention issues relating to Markush claims; and
6. Non-compliance with the foreign filing requirements of the Indian patent law (Section 39);
7. Functional claiming without sufficient structural definition of the claimed invention.

Disclosure and the “Coverage-Disclosure” Gap

Section 10(4) of the Patents Act, 1970 provides that the complete specification shall describe the invention, the manner of performing it and the best method known to the applicant, and conclude with claims defining the scope of protection sought. 64(1)(h) and 64(1)(i) provide for grounds for revocation, including the failure to sufficiently and fairly describe the invention and define the claims on the basis of such description, respectively. Similar provisions apply in Europe under the EPC (Articles 83 and 84) and the PCT (Rules 5 and 6).

The issue of coverage-disclosure gap manifests itself in a variety of ways, but they usually involve either overly broad claims or an overly narrow disclosure. In either situation, the claims seek to protect more than what has been sufficiently disclosed in the specification, rendering them vulnerable to challenges. The Indian Supreme Court in Novartis AG v. Union of India, (2013) 6 SCC 1, while ruling on the application of Section 3(d) of the Patents Act, 1970, noted that the scope of the claims in a patent application must be commensurate with the disclosure in the complete specification. This principle appears to have been consistently applied by the Delhi High Court in biotechnological cases to invalidate claims that seek to cover mutations not sufficiently disclosed in the complete specification and therefore not amenable to the principles of Section 10(4)(b) and 64(1)(h). Similar issues frequently arise before the Indian Patent Office in the context of First Examination Reports.

In European practice, insufficiency of disclosure is assessed under Article 83 EPC in conjunction with Article 84 EPC. Specifically, the EPO considers claims insufficient if a person skilled in the art would not be able to perform the invention on the basis of the description as it stands, at the date of filing, and without undue burdens. Markush-type claims are especially vulnerable if the specification does not sufficiently describe the alternatives; for instance, a claim that encompasses one thousand chemical compounds with only ten exemplified in the specification may be rejected as too broad.

Methods of Treatment and Similar Jurisdiction-Specific Issues

One of the most frequent errors pertains to methods of treatment, particularly the assumption that methods of treatment are patentable subject matter everywhere, as in the United States.

35 USC § 101 does not explicitly prohibit human treatment methods, but they are often excluded from patentability under 35 USC § 271(e) or found unenforceable due to ethical or public policy considerations. Nevertheless, they are routinely included in US patent specifications as claims directed to “treatment of [condition] in a subject in need thereof comprising administering a therapeutically effective number of [compound].” Such claims, however, are entirely invalid in India under Section 3(i) of the Patents Act, 1970 which explicitly prohibits any process for the medicinal, surgical, curative, prophylactic, diagnostic, or therapeutic treatment of human beings or any process for increasing the economic value of any animal or plant or any other similar process.

Added Matter and Article 123(2) EPC

Article 123(2) EPC stipulates that a European patent application or patent shall not be amended so as to contain subject matter not disclosed in the application as filed. This stipulation is hardly ever respected in practice, and the Indian law (Section 59) contains a directly analogous prohibition.

Claims in pharmaceutical specifications are often drafted in the genus-plus-indication format, for instance, “A compound selected from the group consisting of R1, R2, and R3 for use in the treatment of A, B, or C.” Under the “two lists” jurisprudence, selection of a compound from the first list and indication from the second list within the claim language constitute added matter not disclosed in the specification. Technical Board of Appeal of the EPO ruled on this matter in T 1621/16 and held that selection from two lists in a claim language is not permissible unless each selection is individually disclosed in the specification, unless there is an explicit pointer to a combination, or the combination does not involve an undisclosed technical effect.

This issue frequently arises when the PCT application enters the European regional phase pursuant to Rule 162 EPC because the patentee has to reduce the number of claims beyond the 15-claim limit set by Rule 162(2)(a) EPC. The most common solution is to introduce additional claim dependencies at a lower level to consolidate the claims, but such dependencies constitute added matter if the particular combination was not disclosed in the PCT application.

The most important takeaway message is that anything not specifically disclosed in the patent specification is deemed added matter, particularly combinations of individually disclosed elements that were not explicitly stated as such. Each and every claim has to be drafted on the basis of the specification as filed, with specific pointers to passages or embodiments if necessary (such as pointers to figures or tables). The same principle applies to amended claims in subsequent proceedings, with the proviso that any changes must be consistent with the disclosure as filed.

Prosecution History Estoppel

Prosecution history estoppel is a principle that prevents a patentee from asserting claims that have been narrowed during prosecution to overcome objections. Simply put, the patentee may not use the doctrine of equivalents to renounce the limitations built into the claim language at the time of filing. The US Supreme Court articulated the contemporary understanding of prosecution history estoppel in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 US 722 (2002). According to Festo, a narrowing amendment made during prosecution to overcome an objection raises a presumption that the patentee surrendered the scope of the claim that was not included in the amended claim language, and the burden is on the patentee to demonstrate that the amendment was not made in response to a patentability challenge. Indian courts have consistently followed the lead of the US courts in applying prosecution history estoppel.

AstraZeneca AB v. Intas Pharmaceuticals Limited, 2021 SCC OnLine Del 3746 saw the Delhi High Court ruling that the history of claim narrowing in related patent applications filed in India and the US, taken together with its impact on claim construction, was relevant to assessing infringement. In FMC Corporation v. GSP Crop Science Private Limited, 2022 SCC OnLine Del 3784, the Delhi High Court considered prosecution history estoppel as a relevant factor in the context of interim injunctions, finding the patentee’s estoppel arguments to lack merit.

The most interesting question regarding prosecution history estoppel pertains to the application of foreign law in trans-Jurisdictional infringement disputes. In Communication Components Antenna Inc v Ace Technologies Corp (Delhi HC, July 12, 2019), the Delhi High Court examined whether a claim amendment that occurred during the US prosecution could be used as evidence of the patentee’s construction of the claim scope, and by extension, the limits of the corresponding Indian claims. Under Indian law, foreign proceedings do not bind Indian courts, but they are relevant to the extent that they demonstrate how the patentee perceived the patent during the course of litigation. In other words, foreign prosecution history is always relevant to the determination of patentee’s interpretation of a patent, but it is only directly applicable insofar as that interpretation is explicitly articulated in a binding order. Indian courts have not ruled on whether the reverse applies, i.e., whether a patentee may use Indian law proceedings to interpret a foreign patent. At present, patent attorneys must assume that the foreign law equivalent to Indian prosecution history estoppel is in place and factor it into the drafting of claims in applications filed abroad.

Unity of Invention, Disclosure and Markush Claims

Markush-type claims allow a claim to encompass a number of similar compounds with similar modes of action by referring to a group of alternatives, for instance, “a compound selected from the group consisting of…” The claims are a staple of pharmaceutical and agricultural chemical patenting, as they can allow an applicant to cover thousands of variations with one claim, and reduce the costs associated with filing in multiple jurisdictions. Under 37 CFR § 1.63, a single application may claim multiple inventions related to each other in a general inventive concept, but each invention must be disclosed distinctly and specifically so as to be clearly understood and described. Failure to provide sufficient disclosure, particularly in the case of an extensive list of alternatives (over five thousand) with only limited specific examples (thirty), may result in objections under 37 CFR § 1.121 relating to insufficiency of disclosure. In practice, the specification must clearly describe every compound within the claim, or the patentee may be limited in the types of infringement relief available to it.

PCT Rule 13.1 stipulates that a single international application may only relate to one invention, or a group of inventions with one or more special technical features relating to a general inventive concept. PCT Rule 13.2 details what constitutes a special technical feature, namely the one or more features that distinguish the invention from what was previously known. According to IPAB in Esco Corporation v. Controller of Patents & Designs, OA/66/2020/PT/DELIndian law follows the same unity standard as the PCT.

Markush-type claims, which unite a number of structurally similar compounds into one claim, are the only way to ensure such a degree of generality in the claims for chemically related innovations without incurring additional costs for every similar invention. The EPO similarly follows the general inventive concept standard for unity of invention under Article 82 EPC. Unity of invention is seldom an issue within the PCT framework, but it becomes a problematic one when the PCT application is filed in regions not bound by the PCT, such as India, or during subsequent national phases, each of which may raise additional objections based on its own domestic law.

Markush claims often fail the unity test if the group of similar compounds is structurally diverse and united only by function, not structure. A divisional patent application, filed in response to a divisional order, typically follows the priority date of the principal application but only relates to one group of structurally similar compounds disclosed in the original application. If the original application did not specifically disclose any such groups beyond the Markush claim language, the divisional application may fail entirely under the unity requirement.

Section 39 and Other Foreign Filing Restrictions

Section 39 of the Patents Act, 1970 is a notoriously tricky provision that governs foreign filings by Indian residents and inventors and is rarely respected in practice. According to Section 39(2), any Indian citizen who files a patent application abroad for an invention not first filed in India is guilty of an offence and makes the foreign application void. The patentee may apply for a Foreign Filing Licence, Form 25, that allows them to file abroad without prejudice, but such a licence is required in all cases, without exception. The most frequent violations pertain to the following issues, each of which has adverse consequences for the patentee:

1. Failing to enter the national phase within 31 months from the priority date, as required by Rule 159(1) EPC and Rule 20(1) of the Patent Rules, 2003;
2. Failing to provide the required translations upon entry into the national phase;
3. A patentee who proceeds to file a PCT application without first obtaining the foreign filing license or waiting six weeks after filing the Indian patent application.

The least frequent, but by far the most damaging, error occurs when the applicant fails to wait for the six-week period required by Section 39 before filing the foreign application. Once the foreign application is filed, it is impossible to retract it and cancel the offending documents in the foreign patent office, and any subsequent foreign patent based on that application may be vulnerable to challenges on the grounds of invalidity.

Article 4 of the Paris Convention (1883) grants patent applicants with a first filing in India the right to claim priority in other convention countries within one year of the first filing date. A drafter who files the specification under Section 9(1) with the Indian Patent Office to secure a filing date before the invention is fully reduced to practice runs the risk of having the claims invalidated on the grounds of anticipating prior art if the PCT entry or complete specification filing is delayed past the one-year deadline.

Functional Claiming Without Structural Support

Functional claiming, or claiming according to the function of an element rather than its structure, is theoretically the broadest form of claiming because it encompasses all structures that serve the disclosed function. In practice, functional claims invite attacks from infringers who request deletion of the functional language in favor of a specifically disclosed structure or method or challenge the validity of the claim entirely on the grounds of indefiniteness. In US practice, means-plus-function limitations (35 USC § 112(f)) are narrowly interpreted, meaning that structures not explicitly described in the specification are not encompassed by the claim language. Software-related claims are particularly vulnerable because a specification that discloses no algorithm to implement the means for processing or generating data renders such claims indefinite under 35 USC § 112(b). Several decisions of the Federal Circuit, including WMS Gaming Inc v. International Game Technology, 184 F.3d 1339 (Fed. Cir. 1999), have held that means-plus-function claims to software-implemented inventions are invalid if the specification does not explicitly disclose the corresponding structure.

The EPO allows functional definitions only if they are necessary to succinctly describe the invention and cannot be practically defined in another manner (EPO Guidelines for Examination, F-IV, 6.5). Purely functional definitions serve as a basis for objections against insufficiency of disclosure (Article 83 EPC) and lack of clarity (Article 84 EPC). Under Indian law, each specification must conclude with claims that define the scope of protection sought (Section 10(5)), and the Manual of Patent Office Practice and Procedure explicitly requires claims to be definite and completely define the matter for which protection is sought (emphasis added). This has been interpreted to mean that functional claims that fail to specifically define the structure of the invention are invalid under 10(5) and subject to opposition under 64(1)(i).

Conclusion

The preceding discussion demonstrates that the seven mistakes detailed above are the most frequent mistakes in patent claim drafting that undermine international protection, and that these mistakes stem from one source – the failure to consider the international aspect of patent protection during drafting. The PCT does little to resolve the issue, as it simply extends the timeframe for national phase entry and provides a limited search report but does not harmonize substantive patent law. A patent attorney who drafts a PCT application according to the needs of one patent office, for instance, the USPTO, will find such claims to be entirely unacceptable in India, China, and Europe, encountering objections under Section 3(i), Article 123(2), and 39 of the relevant laws, respectively and facing prohibitions on claiming equivalents in infringement litigation in the United States and India. The seven mistakes in patent claim drafting discussed in this article do enormous damage to the prospects of international patent protection, and the patent attorney who fails to avoid them does a great disservice to his client.

Author:- Simran, in case of any queries please contact/write back to us at support@ipandlegalfilings.com or   IP & Legal Filing.

References

Statutes and Rules

1. The Patents Act, 1970, §§ 3(d), 3(i), 9(1), 10(4), 10(5), 39, 59, 64(1)(h), 64(1)(i) (India).
2. The Patents Rules, 2003, r. 20 (India).
3. Convention on the Grant of European Patents (European Patent Convention), arts. 82, 83, 84, 123(2), Oct. 5, 1973, as amended.
4. Implementing Regulations to the Convention on the Grant of European Patents, rr. 159, 162.
5. Patent Cooperation Treaty, rr. 5, 6, 13.1, 13.2, June 19, 1970, as amended.
6. Paris Convention for the Protection of Industrial Property art. 4, Mar. 20, 1883, as revised.
7. 35 U.S.C. §§ 101, 112(b), 112(f), 271(e).
8. 37 C.F.R. §§ 1.63, 1.121.

Cases

1. Novartis AG v. Union of India, (2013) 6 SCC 1 (India).
2. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 (2002).
3. AstraZeneca AB v. Intas Pharmaceuticals Ltd., 2021 SCC OnLine Del 3746 (India)
4. FMC Corp. v. GSP Crop Science Private Ltd., 2022 SCC OnLine Del 3784 (India)
5. Communication Components Antenna Inc. v. Ace Technologies Corp., CS(COMM) 1222/2018 (Del. H.C. July 12, 2019) (India).
6. T 1621/16, EPO Technical Bd. of Appeal (Mar. 19, 2020).
7. Esco Corp. v. Controller of Patents & Designs, OA/66/2020/PT/DEL (IPAB Oct. 27, 2020) (India).
8. WMS Gaming Inc. v. International Game Technology, 184 F.3d 1339 (Fed. Cir. 1999).