Delhi High Court Sets Aside Glisten LLC Patent Refusal Over Lack of Notice

In a significant ruling that reinforces the procedural safeguards of natural justice in patent prosecution, the Delhi High Court on 1 October set aside the refusal of a patent application filed by US-based company Glisten LLC . Justice Purushaindra Kumar Kaurav held that a refusal founded on a ground not put to the applicant before the hearing cannot be sustained, and remanded the matter for fresh consideration.

The decision sends a clear message to the Patent Office : a hearing notice must accurately reflect the objections that the Controller intends to press, and applicants are entitled to rely on that notice. Any deviation—whether reviving an abandoned objection or raising a new one—requires prior intimation and a meaningful opportunity to respond.

Background of the Patent Application

Glisten LLC filed Indian patent application No. 2020XXXXXX (number redacted) in 2020, titled “Gemstone Coating and Methods of Making and Using the Same.” The invention relates to coating compositions for gemstones and methods of application. In the First Examination Report (FER) issued in 2023, the Patent Office raised a single objection: claims 1 to 18 lacked inventive step , being obvious in view of two prior-art documents.

The applicant responded in January 2024, submitting arguments and amendments to address the inventive-step objection. However, the hearing notice issued in June 2024 narrowed the scope of the objection. It only raised the inventive-step ground against claim 18, and specifically on the basis that the specification did not contain working examples to support it.

The Procedural Shortcut

Relying on the hearing notice, Glisten withdrew claim 18, leaving claims 1 to 17 for consideration. At the hearing, the Assistant Controller of Patents and Designs did not indicate any intent to revisit the inventive-step objection for the remaining claims. Yet, in the final order dated 23 January 2026 , the Controller refused the entire application under Section 15 of the Patents Act, 1970 , holding claims 1 to 17 obvious in view of the same prior-art documents that had been referenced in the FER.

The applicant was blindsided. In its appeal before the Delhi High Court , Glisten contended that it had never been informed that the inventive-step objection continued to apply to claims 1 to 17. Had the Controller communicated its real intention, the applicant argued, it could have responded more effectively—by filing additional evidence, submitting expert testimony, or making more pointed amendments.

The Patent Office ’s Defence

The Patent Office defended the refusal on three grounds. First, it argued that the Controller has the power to examine all aspects of an application while passing the final order under Section 15. Second, it submitted that all claims remain open for consideration despite the hearing notice. Third, it maintained that the application lacked inventive step in any event, implying that the procedural flaw was harmless.

Justice Kaurav accepted the Patent Office ’s contention only to a limited extent. The Court agreed that “the Controller is not bound to grant a patent merely because a particular objection does not find mention in the hearing notice.” However, the Court immediately qualified that broad statement with a crucial caveat: “if the Controller proposes to refuse the application on a ground, that ground must first be put to the applicant. The breadth of the power under Section 15 does not dispense with the requirement of notice under Section 14.”

Natural Justice Violation

The Court anchored its reasoning on the fundamental principle of audi alteram partem —the right to be heard. Drawing a distinction between the power to consider all aspects and the duty to notify the applicant of the ground on which refusal is actually based, the Bench observed:

“An applicant is entitled to rely on the hearing notice as issued. If the Controller intends to revive an objection that was not carried forward in the notice or raise a fresh objection, the applicant must be informed and given a meaningful opportunity to respond.”

Applying this principle to the facts, the Court noted that once claim 18 was withdrawn, the only inventive-step objection mentioned in the hearing notice no longer had any claim to which it could attach. The refusal, therefore, “rests entirely on a ground which was not carried into the hearing notice.” This, the Court held, was a manifest breach of natural justice .

The Impact on Patent Prosecution

The ruling clarifies the interplay between Sections 14 and 15 of the Patents Act. Section 14 provides the Controller the power to require the applicant to be heard before refusing a patent; Section 15 gives the Controller the substantive power to refuse if the application fails to meet requirements. The Delhi High Court has now harmonised these provisions: the substantive power under Section 15 cannot be exercised in a manner that bypasses the procedural safeguard of Section 14.

For patent practitioners, the judgment underscores the importance of meticulously preserving the hearing notice and the official record of what was discussed at the hearing. Any objection that appears in the FER but is conspicuously absent from the hearing notice should be treated as abandoned, unless the Controller explicitly puts the applicant on notice that the objection is revived. Conversely, applicants must remain vigilant: if a hearing notice includes only a subset of objections, they should consider whether to proactively address the omitted objections to avoid a later surprise—though the Court’s ruling now makes it clear that the onus lies on the Controller to notify.

Implications for Patent Office Practice

The decision is likely to prompt a revision of internal Patent Office guidelines for issuing hearing notices. Controllers may now be required to list all grounds—including those from the FER that remain pending—rather than focusing on a single contentious claim. The ruling also reinforces the role of the hearing as a genuine opportunity to be heard, not a mere formality preceding a pre-ordained refusal.

Moreover, the judgment may encourage more applicants to challenge refusal orders that stray beyond the scope of the hearing notice. Given the Court’s strong language, the Patent Office may face increased litigation unless it adopts a more transparent practice.

Conclusion

The Delhi High Court allowed the appeal, set aside the order dated 23 January 2026 , and restored the patent application to the Controller for fresh consideration in accordance with the Patents Act and applicable Rules. All rights and contentions of the parties remain open. The Court specifically clarified that its observations were confined to the principles of natural justice and should not influence the decision on the merits of the patent application.

The judgment serves as a timely reminder that even in the highly technical field of patent law, procedural fairness remains non-negotiable. As the Court succinctly put it: a refusal founded on a ground not put to the applicant before the hearing cannot stand. For Glisten LLC , that means a second chance to argue the merits. For the Patent Office , it means a clear direction to keep applicants fully informed of the case they have to meet.