Introduction
The decision of the Delhi High Court in Neurocentria Inc. v. Deputy Controller of Patents and Designs is an important ruling on the interplay between patent priority claims, national phase entry deadlines, requests for examination, and the power to amend patent applications under the Patents Act, 1970.
The judgement addresses a recurring issue in patent prosecution: whether an applicant who has missed mandatory statutory deadlines can subsequently amend or disclaim an earlier priority date in order to bring the application within the prescribed time limits.
The court examined the scope of Section 57(5) of the Patents Act, 1970, and considered whether a patent applicant could amend its priority claim fourteen years after filing the application.
The Court ultimately held that such an amendment cannot be permitted where its sole purpose is to circumvent mandatory statutory timelines and revive an application that has already become liable to be treated as withdrawn.
Factual And Procedural Background
The appellant, Neurocentria Inc., filed a Patent Cooperation Treaty (PCT) international application on 24 March 2008.
The PCT application claimed three priority dates from United States provisional applications:
| Priority Application | Application Number | Priority Date |
|---|---|---|
| First Priority | US Application No. 60/896,458 | 22 March 2007 |
| Second Priority | US Application No. 60/994,902 | 20 September 2007 |
| Third Priority | US Application No. 61/066,592 | 20 February 2008 |
Thereafter, the appellant entered the national phase in several jurisdictions and filed Indian Patent Application No. 1015/DELNP/2010 on 15 February 2010.
A Request for Examination (RFE) was filed on 16 September 2011.
When the First Examination Report (FER) was issued on 14 March 2018, the Patent Office raised an objection that the application had not complied with statutory timelines because the earliest priority date of 22 March 2007 had not been disclosed in Form 1 and the RFE had not been filed within forty-eight months from that earliest priority date.
The applicant responded that it had intentionally chosen to rely upon the second priority date and had effectively disclaimed the first priority date at the time of national phase entry.
According to the applicant, if the second priority date of 20 September 2007 were treated as the operative priority date, both the national phase filing and the RFE would fall within time.
A hearing was initially fixed in 2019. Owing to alleged negligence of the patent agent, the hearing was missed and the application was refused.
Subsequently, the Patent Office granted an extended hearing in 2024.
The applicant then filed Form 13 on 28 June 2024, seeking amendment of the priority claim by disclaiming the earliest priority date.
The Deputy Controller rejected the amendment request and treated the application as withdrawn.
This order was challenged before the Delhi High Court under Section 117A of the Patents Act.
The Core Dispute Before The Court
The central issue before the Court was whether the applicant could, after many years, invoke Section 57(5) of the Patents Act to disclaim its earliest priority date and substitute the second priority date as the operative priority date.
Arguments Of The Applicant
- The first priority date had effectively been abandoned from the beginning.
- Form-13 merely sought to formally record what had always been intended.
- Section 57(5) expressly permits amendment of priority claims and does not prescribe any limitation period.
- The applicant should not be penalized for the negligence of its patent agent.
Arguments Of The Patent Office
- The earliest priority date governed the thirty-one month deadline for entering the national phase under Rule 20(4)(i).
- The earliest priority date also governed the forty-eight-month deadline for filing the RFE under Rule 24B.
- Both statutory deadlines had already expired.
- The application stood withdrawn by operation of law.
- A later amendment could not be used to defeat mandatory statutory provisions.
Reasoning And Analysis Of The Judge
The Court noted that Rule 20(4)(i) requires entry into the Indian national phase within thirty-one months from the priority date referred to in Article 2(xi) of the PCT.
Where multiple priorities are claimed, Article 2(xi) specifically treats the earliest priority date as the relevant date for calculating deadlines.
Calculation Of Deadlines
| Event | Applicable Date | Required Deadline | Actual Date |
|---|---|---|---|
| Earliest Priority Date | 22 March 2007 | – | – |
| National Phase Entry | Based on Earliest Priority | 22 October 2009 | 15 February 2010 |
| Request for Examination (RFE) | Based on Earliest Priority | 22 March 2011 | 16 September 2011 |
Applying these provisions, the court held that the national phase application ought to have been filed by 22 October 2009, being thirty-one months from 22 March 2007.
Since the application was actually filed on 15 February 2010, it was filed approximately four months late.
Likewise, the RFE should have been filed on or before 22 March 2011 but was filed only on 16 September 2011.
The Court observed that the applicant admittedly omitted the earliest priority date from Form-1 and disclosed only the second and third priorities.
The court found that this omission operated to the applicant’s advantage because it artificially extended both statutory deadlines.
The court noted that there was no contemporaneous request for a disclaimer when the application was filed and that the first formal request seeking a disclaimer appeared only in Form-13 filed in June 2024.
Mandatory Nature Of Patent Deadlines
A significant part of the judgment is devoted to the mandatory nature of patent prosecution deadlines.
The Court held that deadlines relating to national phase entry and filing of an RFE are non-extendable and are treated differently from procedural deadlines that may sometimes be relaxed in exceptional circumstances.
Discussion of Earlier Judgments
The Court extensively considered the decision in Nippon Steel Corporation v. Union of India. In that case, the Delhi High Court had held that although Section 57(5) permits amendment of a priority date, such amendment can only be sought while a patent application continues to exist in law. Once an application stands withdrawn under Section 11B(4), a later amendment cannot revive it. The Court quoted the observation that merely because no limitation period is prescribed for amendment of a priority date does not mean that such an application can be filed after the patent application has ceased to exist.
The Court also relied upon Diebold Self Service Systems v. Union of India, where a Division Bench had upheld the validity of Rule 22 and emphasised that national phase entry deadlines are mandatory. The Division Bench had ruled that failure to comply with the statutory period results in deemed withdrawal and that courts cannot create extensions not contemplated by legislation.
The applicant relied heavily upon decisions such as European Union represented by the European Commission v. Union of India, Bry-Air Prokon Sagl v. Union of India and Bry-Air (Asia) Pvt. Ltd v. Union of India. However, the court distinguished these authorities on the ground that they concerned different categories of deadlines, particularly delays in responding to examination reports or exceptional writ jurisdiction cases. They did not authorise extension of national phase entry deadlines or RFE deadlines, which have consistently been regarded as mandatory.
The Court therefore rejected the argument that negligence of a patent agent could justify extension of these particular statutory timelines. Even if the applicant had acted in good faith, the statutory scheme did not permit revival through amendment.
The Court further held that allowing the amendment would effectively permit the applicant to achieve indirectly what it could not achieve directly. Since the proposed disclaimer was intended solely to overcome missed statutory deadlines, the amendment could not be permitted.
Key Principles Emerging from Earlier Judgments
- Amendment of a priority date is permissible only while the patent application remains legally subsisting.
- An application deemed withdrawn cannot be revived through a subsequent amendment.
- National phase entry deadlines are mandatory and cannot be extended by judicial interpretation.
- RFE filing timelines are statutory and non-extendable.
- Negligence of a patent agent does not override mandatory patent law provisions.
Final Decision of the Court
The Delhi High Court upheld the order of the Deputy Controller of Patents and Designs. It held that the patent application had not been filed within thirty-one months from the earliest priority date and that the Request for Examination had not been filed within forty-eight months from that date. The Court concluded that the application stood withdrawn under the statutory scheme and that Form-13 could not be used fourteen years later to alter the priority date and revive the application. Consequently, the appeal was dismissed.
Point of Law Settled
The judgement settles several important principles of Indian patent law.
- A patent applicant cannot disclaim or amend an earlier priority date under Section 57(5) merely to overcome missed statutory deadlines for national phase entry or filing a request for examination.
- The thirty-one month deadline for entering the national phase under Rule 20(4)(i) and the forty-eight month deadline for filing an RFE under Section 11B read with Rule 24B are mandatory and non-extendable.
- Where multiple priority claims exist in a PCT application, the earliest priority date governs computation of statutory timelines.
- Even though Section 57(5) permits amendment of priority claims, such amendment can only be sought in respect of an application that continues to exist in law. Once an application is deemed withdrawn, amendment cannot revive it.
- Negligence of a patent agent, however unfortunate, cannot be used to circumvent statutory provisions governing non-extendable patent deadlines.
Legal Position Clarified by the Delhi High Court
| Issue | Court’s Finding |
|---|---|
| Amendment of Earliest Priority Date | Cannot be used to overcome missed statutory deadlines. |
| National Phase Entry Deadline | Mandatory and non-extendable. |
| Request for Examination (RFE) | Must be filed within the prescribed statutory period. |
| Multiple Priority Claims | Earliest priority date governs limitation calculations. |
| Deemed Withdrawal | Application cannot be revived through amendment. |
| Patent Agent Negligence | Does not justify extension of mandatory timelines. |
Case Details
| Case Title | Neurocentria Inc. Vs. Deputy Controller of Patents and Designs |
|---|---|
| Date of Order | 18 May 2026 |
| Case Number | C.A. (COMM.IPD-PAT) 5/2025 |
| Neutral Citation | 2026:DHC:4418 |
| Court | High Court of Delhi |
| Honourable Judge | Justice Jyoti Singh |
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi.
Disclaimer: Readers are advised not to treat this as a substitute for legal advice, as it may contain errors in perception, interpretation, and presentation.
