In the case of Adiuvo Diagnostics Private Limited vs Union of India & Ors. [W.P.(IPD)No.23 of 2023], the writ petitioner, Adiuvo Diagnostics, challenged the order passed by the Controller of Patents granting patent number 439474 to University Health Network for the invention titled “Device and Method for Fluorescence-based Imaging and Monitoring”, after rejecting the pre-grant opposition filed by the petitioner.

The petitioner approached the Madras High Court contending that the impugned order lacked reasoning for rejecting their contentions made during the pre-grant opposition proceedings. They primarily argued that:

• The expert affidavits submitted by them were not considered in substance; the impugned order merely referenced the prior arts cited within the affidavits.
• The arguments presented by the patentee regarding novelty and patentability under Section 3(k) were accepted without providing a detailed reasoning.
• The novelty test was incorrectly applied to assess obviousness. The petitioner specifically argued that while the Controller acknowledged the petitioner’s claim regarding prior art D3, the finding of non-obviousness was based solely on the fact that prior art documents D1 and D2, in combination with D3, did not disclose all features of the claimed invention.
• The objection raised under Section 3(d) was rejected solely on account of novelty without adequate analysis.

The petitioner argued that the impugned order was not just inadequately reasoned but entirely unreasoned, warranting judicial review under Article 226. To support their stance of maintainability of a writ petition at the pre-grant stage, the petitioner relied on several precedents including: Regents of the University of California vs Union of India & Ors. [2019 SCC OnLine Del 8590], Best Agrolife Limited vs Deputy Controller of Patents & Anr. [2022 SCC OnLine Del 1982], Indian Network for People Living with HIV/AIDS vs Union of India & others [2008 SCC OnLine Mad 892], Whirlpool Corporation v. Registrar of Trade Marks, Mumbai & Ors [1998 AIR SCW].

The respondent argued that the petitioner was given sufficient opportunity to present their case before the Controller, and the impugned order was passed after an extensive hearing. They emphasized that the Patents Act, 1970, does not provide for an appeal against the rejection of a pre-grant opposition and the correctness of the Controller’s decision cannot be challenged through a writ petition. They maintained that the principles of natural justice were duly followed by the Controller in passing the impugned order and contended that a writ petition cannot function as an appeal in disguise. Further, they highlighted that the petitioner has alternative legal remedies, including filing a post-grant opposition, initiating a revocation petition, or filing an if unsuccessful in the post-grant opposition. To support their stance that the writ petition was not maintainable, they relied on judicial precedents including: Ucb Farchim Sa vs Cipla Ltd. & Ors. [2010 SCC OnLine Del 523], Rich Products Corporation vs Controller & Anr. [W.P.(C)-IPD 8/2024,], Rich Products Corporation vs Controller & Anr. [LPA 257/2024], Mylan Laboratories Limited vs UOI & Ors. [2019 SCC OnLine Del 10319].

The Delhi High Court’s position in UCB Farchim, which was later reaffirmed in Rich Products Corporation and Mylan Laboratories, was that a writ petition against the rejection of a pre-grant opposition may be entertained if the petitioner does not qualify as a “person interested” under Section 2(1)(t) of the Patents Act. However, if the petitioner is a “person interested” the Court would ordinarily refrain from exercising writ jurisdiction in view of the alternative statutory remedies available.

The Madras High Court, in its decision dated March 25, 2025, opined that while availability of an alternative remedy is a relevant and significant consideration, it does not by itself exclude or whittle down the Court’s writ jurisdiction. The Court emphasized that Article 226 endows High Courts with wide discretionary powers, exercisable when a statutory authority fails to act within its jurisdiction, exceeds its authority, or exercises jurisdiction perversely. The Court further underscored that judicial review under Article 226 is primarily concerned with examining the decision-making process rather than the decision itself. The Court thus concluded that the existence of an alternative remedy, though material, is not necessarily conclusive in determining whether writ jurisdiction should be exercised. Accordingly, the Court proceeded to assess whether the impugned order warranted interference in light of the settled principles governing writ jurisdiction.

During its analysis, the Court noted that the impugned order made no reference to the expert affidavits submitted by the petitioner. While the respondent contended that one of the affidavits merely referred to cited prior arts that were discussed in the impugned order, the Court concurred with the petitioner that referencing prior arts in the impugned order cannot be equated with a substantive consideration of affidavits as evidence. The Court highlighted that this omission was particularly significant in the context of the obviousness analysis, which requires an assessment from the standpoint of a person skilled in the art (PSITA). When affidavits are submitted by individuals claiming expertise in the relevant field, it is incumbent upon the Controller to consider them and provide reasoned conclusions for either accepting or rejecting their opinions.

The Court also observed that, prima facie, the Controller had not conducted an independent obviousness analysis to assess the inventive step of the subject application. Instead of providing independent reasoning, the Controller had merely accepted the patentee’s contentions while summarily rejecting those of the petitioner.

However, the Court recognized that while exercising its discretionary jurisdiction under Article 226 in cases where there is no provision of a statutory appeal, it must be cautious not to allow a writ petition to serve as an appeal in disguise. This consideration was particularly relevant to the instant case since the petitioner qualified as a “person interested” and had alternative remedies, including post-grant opposition and revocation under Section 64. The Court also acknowledged that although the impugned order lacked consideration of affidavits and reasoning on material issues, interfering with the impugned order when the patent had just over three years of validity remaining, would unduly prejudice the patentee.

Consequently, the Court deemed it appropriate to consider a workable and balanced alternative. It noted that although the statutory deadline for filing a post-grant opposition had lapsed, the petitioner had initiated the writ proceedings well within that timeframe. In light of this, the Court held that the time spent in prosecuting the writ petition could be excluded for the purpose of computing the limitation period, and accordingly directed the Patent Office to accept the post-grant opposition by the petitioner if filed within thirty days from receipt of a copy of the Court’s order.

In addition, the Court extended the interim protection previously granted during the pendency of the writ petition, which restrained the patentee from prosecuting the petitioner on the basis of the subject patent on the condition that the petitioner’s activities are confined to the use of its own patented technology in IN323440. While the patentee opposed this relief as akin to an anti-suit injunction, the Court found it justified in the specific facts of the case and directed that the restraint would remain in force until the post-grant opposition is finally decided and shall cease to operate thereafter, subject to the outcome of the proceedings. The Court also clarified that continuation of the interim order will also be subject to the outcome of opposition proceedings relating to IN323440.