By Jigyasa Pareek

The Madras High Court, in Merck Sharp & Dohme B.V. vs Union of India & Ors. [W.P. (IPD) No. 24 of 2025; decision dated February 12, 2026], considered the effect of successive pre-grant oppositions on the prosecution of a patent application and the obligation of the Controller to apply its mind before issuing notice under Rule 55(3) of the Patents Rules, 2003. The Court observed that while any person is entitled to file a pre-grant opposition, the Controller cannot mechanically issue notices upon every such opposition and keep the application remaining pending indefinitely.

The petition concerned patent application number 408/CHENP/2014, dated 2012, relating to compound acalabrutinib, used in treatments for cancer.

The prosecution of the application became entangled in a series of pre-grant oppositions. The first opposition was filed in January 2019, followed by a second in April 2022. Although written submissions in the second opposition were filed by September 2023, no decision was taken until February 2024, when a third opposition was also filed. By the time the hearing notice was issued in the third opposition, a fourth pre-grant opposition, described as a benami opposition, was filed in July 2024, pursuant to which the Controller issued the impugned notice under Rule 55(3)(b) in September 2024.

The Petitioner challenged the notice and sought, inter alia, directions for disposal of the earlier oppositions within a fixed period and that any further pre-grant opposition raising grounds or prior-art documents already relied upon in the earlier oppositions be summarily rejected. Alternatively, the Petitioner sought a fresh notice containing reasons demonstrating the Controller’s prima facie assessment under Rule 55(3)(b).

The principal grievance before the Court was the failure to bring the prosecution of the patent application to a conclusion while repeatedly acting upon subsequent oppositions. The Petitioner contended that the four oppositions substantially raised the same grounds and that the notices issued by the Patent Office did not reflect the application of mind contemplated in Rule 55(3). It also pointed to delays at different stages of the prosecution, including the time taken in issuing the FER and hearing notices and in acting upon the earlier opposition proceedings.

The Court did not determine whether the opposition was genuine, frivolous or otherwise lacking in merit, however, it focused on the manner in which the Controller had handled the application. It traced the prosecution from July 2012 and noted that the application had not reached culmination even by 2026. It noted that written submissions in the second opposition had been completed in September 2023, but no decision was taken between October 2023 and February 2024. During this period, another pre-grant opposition came to be filed, triggering another round of notice, reply and hearing proceedings. This was followed by the fourth opposition in July 2024. The Court observed that the Patent Office had not acted upon the pending application by taking a final decision, and that successive oppositions had consequently accumulated.

The Court emphasised that it is the duty of the Patent Office to apply its mind whenever a pre-grant opposition is received, as mandated by Rule 55(3), introduced in 2024 as part of the Patents (Amendment) Rules. It explained that since any person can oppose the grant of a patent, and an opposition may originate from anywhere in the world, the Rules require the Controller to be prima facie satisfied before proceeding with the opposition. The Controller, therefore, cannot mechanically issue a notice every time a pre-grant opposition is received. According to the Court, allowing such a mechanical process, coupled with delay in deciding the patent application, could defeat the rights of a patent applicant and the objective underlying the introduction of Rule 55(3).

The Court was particularly critical of the explanation offered by the Controller in its counter-affidavit wherein it was merely stated that the applicable provisions and procedural mandates had been followed, and no explanation was provided as to why the earlier oppositions had not been taken up expeditiously and decided.

The Court consequently disposed of the writ petition by prescribing a time-bound mechanism for bringing the proceedings to an end. The Petitioner was directed to file its reply to the fourth pre-grant opposition within four weeks. The Controller was directed to decide the first, second, third and fourth pre-grant oppositions within three months, after affording an opportunity to the Petitioner and the fourth opponent. The Court also addressed the possibility of further oppositions during this period, directing that any further pre-grant opposition received by the Controller be dealt with strictly in accordance with Rule 55(3) of the Patents (Amendment) Rules, 2024.