Calcutta High Court Quashes Patent Rejection Over Procedural Lapses in Prior Art Disclosure

The Calcutta High Court recently set aside the Controller of Patents and Designs’ decision rejecting a patent application filed by UCB Pharma GmbH, highlighting significant procedural irregularities in the patent prosecution process. The ruling, delivered on April 8, 2025, in the case UCB Pharma GmbH & Anr. v. The Controller of Patents and Designs (IPDPTA No. 117 of 2023), underscores the necessity of procedural fairness and statutory compliance in patent examination.

The patent application concerned a composition titled “Polyvinylpyrrolidone for the Stabilization of a Solid Dispersion of the Non-crystalline Form of Rotigotine,” directed to a solid dispersion comprising rotigotine and polyvinylpyrrolidone (PVP) in specific weight ratios. Rotigotine is used in Parkinson’s disease therapy, and the invention aimed to enhance the stability of rotigotine in a transdermal therapeutic system (TTS) by preventing crystallization.

Initially filed with 14 claims, the application underwent two rounds of amendments in response to the First Examination Report (FER) and a hearing notice, ultimately narrowing the claims to eight. These claims detailed technical features such as rotigotine in free base form combined with PVP within a precise ratio range and defined dissolution limits in silicone adhesive matrices.

During prosecution, the Controller issued a hearing notice citing three prior art documents (D1 to D3). However, at the hearing, the Controller introduced two additional prior art references, D4 (EP2177217) and D5 (US2005/0079206), which had not been previously disclosed to the applicant. This late introduction of new prior art was a critical procedural lapse identified by the Court.

The Controller refused the patent application on grounds including lack of inventive step, lack of clarity under Section 10(4), and non-compliance with Section 2(1)(j) of the Patents Act, 1970. The inventive step objection was based on the contention that rotigotine, its use in TTS, its combination with PVP, and the use of silicone adhesives were all known from the cited prior art. The Controller argued that selecting a specific rotigotine:PVP ratio was a routine optimization lacking inventive ingenuity.

UCB Pharma countered that their invention addressed a longstanding technical challenge related to the instability of rotigotine in TTS due to crystallization. They highlighted that their earlier product, the Neupro® patch with a 9:2 rotigotine to PVP ratio, required cold chain maintenance due to stability issues. The current invention claimed improved ratios ranging from 9:4 to 9:6, enabling room temperature stability. The appellant submitted comparative data demonstrating superior long-term stability within the claimed ratio range and argued that none of the cited prior art disclosed or suggested these critical ratios.

The Court found multiple procedural and substantive deficiencies in the Controller’s order. It held that introducing new prior art documents D4 and D5 at the hearing stage without prior notice violated principles of natural justice and statutory requirements under Section 13(3) of the Patents Act and Rule 24B of the Patent Rules. Additionally, the refusal of claims 4 to 7 on grounds not raised in the hearing notice was deemed procedurally improper.

Further, the Court observed that the Controller failed to properly re-examine the application after amendments, contravening statutory mandates. The refusal order was also criticized for lacking clarity and reasoning, rendering it a non-speaking order.

In its analysis, the Court reaffirmed established tests for inventive step assessment, including the “Obvious to Try,” “Problem-Solution,” “Could-Would,” and Teaching-Suggestion-Motivation (TSM) approaches. It cited precedents such as Guangdong Oppo Mobile Telecommunications Corp., Ltd., Man Truck Bus Se, Otsuka Pharmaceutical Co. Ltd., Perkinelmer Health Sciences Inc., and Protean Electric Ltd., which consistently disapprove of introducing new prior art at advanced stages without due notice.

Consequently, the Calcutta High Court set aside the impugned refusal order and remanded the matter to the Patent Office for fresh consideration by a different officer. The Court directed that the fresh decision be rendered within six months of receipt of the order.

The case now awaits re-examination under judicial supervision, reinforcing the imperative of procedural fairness and adherence to statutory norms in patent prosecution in India.