Amending claims in Indian patent applications

When filing for a patent, applicants make every effort to ensure that the claim and the specification contained in the application are absolutely perfect. But on many occasions, claims and specifications need to be amended. Indian patent law recognises that it is not possible to always get it right in the first instance and provides for a limited number of circumstances in which claims can be amended, and the process that needs to be followed.

In India, Section 57 of the Indian Patents Act 1970 (the ‘Act’) allows a patent application, the complete specification, or related documents to be amended, either voluntarily or in response to objections raised during the examination of the application, and the amendments may be made before or after the patent is granted.

Section 58 of the Act states that amendments may be made where the validity of a patent is challenged in a legal suit before a court of law. So, for example, if a court decides that a patent is invalid, it may permit the specification to be amended instead of having the patent revoked outright.

However, amendments under Sections 57 and 58 are subject to conditions stipulated in Section 59 of the Act, which are as follows:

• An amendment can only be by way of a disclaimer, a correction, or a clarification/explanation;

• The amendment must only be for the incorporation of an actual fact;

• The amendment should not add any matter that has not already been disclosed in the specification; and

• Any claim that is amended must fall entirely within the scope of the claim of the specification filed originally.

This article explains the permissible claim amendments, while identifying key factors that applicants must look out for while seeking such changes.

Amendment by way of a disclaimer entails, for example, adding a feature or a clause to narrow down the scope of the claim, merging multiple claims, or deleting a claim.

Sometimes, adding a disclaimer clause in the claim may be helpful to overcome objections relating to subject matter exclusions. For example, in the case of a method involving the use of stem cells, a claim may be allowed if a disclaimer is added to the effect that the method does not use stem cells derived from embryonic cells. Similarly, a disclaimer may be added to a claim directed to a method of treatment to specify that the method pertains to a cosmetic procedure only. However, such disclaimers are only allowed if there is support in the specification as filed for such methods.

The deletion of a claim must be done with particular caution. The Indian courts have time and again held that “what is not claimed is disclaimed”. Thus, deletion of a claim may be construed as disclaiming the subject matter itself. This may also adversely affect the possibility of filing a divisional application based on that claim.

The next type of amendment is correction, which is usually for correcting clerical or typographical mistakes. However, the nature of the corrections also need to be carefully determined.

In Enercon (India) v Alloys Wobben (ORA/39/2009/PT/CH), the patentee sought amendments to avoid revocation. Several claims were sought to be amended, some of which were classified as corrections. Some corrections were rejected because the Intellectual Property Appellate Board (IPAB) (now abolished) concluded that the corrections in fact altered the function of the adjusting device originally claimed. By altering the scope of the claims, the corrections in effect widened the claims and thus could not be permitted.

A third type of amendment to claims is by way of explanation, which is usually to provide a clarification to the claim, or to make the claim clear.

In Allegro Pharmaceuticals v. Controller of Patents and Designs (OA/12/2020/PT/CHN), the original claim 1 read as “A composition of matter comprising an RGCysteic Acid Peptide comprising Glycine-Arginine-Glycine-Cysteic(Acid)-Threonine-Proline”. The controller interpreted the claim as a claim directed to a composition and raised an objection for clarity, insisting the claim be amended to recite all components of the composition.

The applicant amended the claim to read as “A compound comprising a peptide, wherein the peptide comprises Glycine-Arginine-Glycine-Cysteic(Acid)-Threonine-Proline”. The controller rejected the amended claim 1 for violating the provisions of Section 59 as the claim directed to a compound would be broader than a claim directed to a composition containing said compound, that the present application was a national phase application, and original claims were drafted in compliance with US patent practice. As per US patent law, ‘composition of matter’ is one of the four principal categories of things that may be patented. A newly synthesised chemical compound or molecule can be patented as a composition of matter.

The IPAB held that no applicant should suffer for the error in the initial drafting of the claims. The IPAB, considering this a special case, allowed the amended claim with further amendment.

Any amendments that are made to claims must always be supported by the specification that was originally filed. So, if a claim is amended by adding a feature that was not part of any of the original claims, that new feature must be supported in the original specification. In AGC Flat Glass Europe v. Anand Mahajan and Ors. (I.A. No. 13519/2007 in CS (OS) No. 593/2007), the Delhi High Court allowed the patentee to bring limitation from the description into the claim, so long as it did not alter the scope of the invention.

The specification as a whole is considered while assessing if the amendment is supported. The support may be explicit or implicit. In Prism Cement v. Controller of Patents and Designs (OA/7/2016/ PT/MUM), the IPAB held that drawings filed with the patent application may be used to show support for claim amendments.

Section 59 requires that the scope of the amended claims must be wholly within the scope of the original claim set.

In Nippon A&L v. Controller of Patents (C.A.(COMM.IPD-PAT) 11/2022), the original ‘product by process’ claims were converted into a process method claim that was rejected by the controller on the ground that it was in contravention of Section 59. The Delhi High Court said that there was common understanding that a product claim is broader in scope than a process claim. Therefore, this amendment was narrower in scope and satisfied the conditions of Section 59.

Claims directed to the mere use of a substance are not allowed in India. A claim directed to a method but written in the form of a use claim is also treated as a use claim in India. Accordingly, the amendment of a use claim into a method claim is likely to be rejected, as held by the controller in Indian Patent Application No. 7994/CHENP/2012.

In Boehringer Ingelheim International v. The Controller of Patents ([C.A. COMM.IPD-PAT] 295/2022 & I.As.10369-70/2022) before the Delhi High Court, the applicant challenged an order of the controller refusing its divisional application. As it transpired, the claims of the divisional application were based on new claims that had been filed via voluntary amendments to the parent application. But the voluntary amendments had not been taken on record in the parent application, because they were beyond the scope of the original claims and thus in violation of Section 59.

One requirement of filing a divisional application in India is that its claims must be based on the claims filed in the parent application. Here, the claims of the divisional application were not included in the parent application and were instead based on the disclosure of the parent application.

The court said that once the subject matter is disclosed in a patent specification, that subject matter is considered as disclaimed, and thus unavailable for further claiming. The applicant’s appeal was rejected. Thus, not only were the additional claims filed during the prosecution of the parent application rejected, but also the divisional application based on those claims.

The addition of new dependent claims often invites an objection from the controller under Section 59. However, the IPAB, in Tony Mon George the Regents of the University of Michigan v. Controller of Patents and Designs (OA/48/2020/PT/DEL), has clarified that inserting a dependent claim is not the same as inserting a new claim. This is because dependent claims merely qualify and limit the scope of already-defined subject matter of the corresponding independent claim.

Amendments to claims may also be permitted in revocation proceedings, where the validity of a patent is challenged in a suit before a High Court. The amendment may be allowed at the discretion of the court. In such matters, besides clear support for the amendment in the complete specification, the court additionally examines the conduct of the patentee, particularly whether there was an unjustifiable delay in seeking the amendment.

In AGC Flat Glass Europe v. Anand Mahajan and Ors. (I.A. No. 13519/2007 in CS (OS) No. 593/2007), for example, the Delhi High Court said that if the patentee knew of the objection for many years before publication, a delay in seeking amendment would itself be a ground for refusal. In Enercon India v. Aloys Wobben (ORA/6/2009/PT/CH), the IPAB said it would be justified in refusing the amendment if the respondent’s conduct was not fair. In the related case of Enercon India v. Aloys Wobben (ORA No. 9/2009/PT/CH, ORA No. 20/2009/PT/CH and ORA/41/2009/PT/CH), the IPAB said that an amendment sought after an unreasonable delay would not be allowed unless the patentee shows reasonable grounds for such delay.

The law and practice in India show that while amendments to claims may be made, there is a limited set of conditions under which such amendments may be sought and allowed. The types of amendments are restricted to disclaimers, corrections, or explanations.

Amendments can be sought during the course of prosecuting a patent application or to prevent a patent from being invalidated through revocation proceedings. However, in all circumstances, the amendment must be fully supported by the specification as originally filed. Also, the scope of amended claims must fall within the scope of claims originally filed.

The conduct of the patent applicant is also of relevance. Any delay in seeking an amendment or a display of evident bad faith can work against the applicant and may lead to the amendment being eventually refused.

Adequate diligence and caution, therefore, must be exercised while seeking an amendment to a patent or an application in India.