Delhi High Court Rejects Zydus Plea Against Helsinn's Nausea Medication Patent
Ayushi Shukla
1 Jan 2026 7:35 PM IST
The Delhi High Court has refused to interfere with the grant of a pharmaceutical patent for a nausea medication dismissing a challenge by Zydus Healthcare Ltd. against Swiss drugmaker Helsinn Healthcare SA
The court held that the Patent Office committed no jurisdictional error and did not violate principles of natural justice while granting the patent.
In a judgment dated December 24, 2025, Justice Tejas Karia clarified that a pre-grant opposition and the examination of a patent application are two distinct and independent proceedings. An opponent at the pre-grant stage, the court said, has no right to participate in or seek a hearing during the examination process.
The patent relates to an invention titled “Compositions and Methods for Treating Centrally Mediated Nausea and Vomiting.” Helsinn's application was filed in April 2012 and originally contained 51 claims.
During prosecution, Helsinn sought voluntary amendments, stating that these were necessary to more clearly define the invention. A First Examination Report was later issued by the Patent Office, following which further amendments were made.
Zydus filed a pre-grant opposition, alleging that the amendments impermissibly expanded the scope of the claims and that mandatory requirements under the Patents Act and Rules were not complied with. A hearing on the opposition was held in May 2022, after which the Patent Office reserved its order.
After reserving its decision on the opposition, the Patent Office issued a separate hearing notice to Helsinn during the examination stage. Additional amendments followed. In March 2023, the Patent Office rejected Zydus' pre-grant opposition and granted the patent to Helsinn.
Zydus then approached the Delhi High Court, arguing that it ought to have been given another opportunity for a hearing and that denial of such a hearing violated principles of natural justice.
Rejecting this contention, the court noted that the grounds raised by Zydus had already been considered during the pre-grant opposition hearing. The subsequent examination proceedings, it said, were independent of that process.
“The right of hearing of the opponent under Rule 55 of the Rules is confined to a consideration of issues raised in the Pre-Grant Opposition. The two processes are separate from each other as the examination process demands a focused evaluation of the application while the opposition process is to address the concerns of external stakeholders,” the Court said.
On the issue of claim amendments, the Court held that there is no legal requirement to pass a separate order on voluntary amendments made before the issuance of the First Examination Report.
The court also declined to entertain the petition on territorial jurisdiction. It held that in writ petitions challenging Patent Office orders, jurisdiction lies with the High Court within whose territorial limits the concerned Patent Office is situated. Since the patent was granted by the Mumbai Patent Office, the Delhi High Court lacked jurisdiction.
Finding no procedural illegality or breach of natural justice, the court dismissed Zydus Healthcare's petition and upheld the patent granted to Helsinn Healthcare.
Case Title: Zydus Healthcare Ltd. v. Assistant Controller Of Patents And Designs & Anr.
Citation: 2026 LLBiz HC (DEL) 3
Case Number: W.P.(C)-IPD 23/2023
For Petitioner: Senior Advocate Dayan Krishnan with Advocates Adarsh Ramanujan, Bitika Sharma, Vrinda Pathak, P.S. Manjunathan, Sandhya Kukreti, Shreedhar and Parth Singh
For Respondents: Advocates Vikrant N. Goyal, Prince Balyan, Kunal Dixit and Sachit Sharma for R-1; Senior Advocate Amit Sibal with Advocates Pravin Anand, Dhruv Anand, Udita Patro, Dhananjay Khanna, Nimrat Singh, Smriti Nair, Saksham Dhingra and Suditi Batra for R-2