In a notable decision in Fresenius Medical Care Deutschland GmbH vs Controller General of Patents [C.A.(COMM.IPD-PAT) 302/2022, decision dated April 16, 2025], the Delhi High Court affirmed the validity of auxiliary claims in patent prosecution. The Court allowed the Appellant’s request to amend and introduce an auxiliary set of claims during the appellate stage.

The appeal was filed against the refusal of the Appellant’s patent application number 7493/DELNP/2012, entitled “Microvesicles (MVs) derived from adult stem cells for use in the therapeutic treatment of a tumor disease”. The subject application had been refused on the grounds of lack of novelty, lack of inventive step, non-patentability under Sections 3(e) and 3(i), and insufficiency of disclosure.

During the course of the appeal, the Appellant relied on an auxiliary set of claims before the Court which were not considered by the Controller of patents.  

While examining the amendment request, the Court reinforced the principle established in the case of Societe Des Produits Nestle SA vs Controller of Patents and Designs and Anr. [2023 SCC OnLine Del 582] and Opentv Inc. vs Controller of Patents, [2023 SCC OnLine Del 2771], reiterating that in an appeal against a refusal order, the High Court has the same powers as the Controller under Section 15 of the Patents Act, including the power to require amendment. The Court emphasised that amendments to claims can be permitted even at the appellate stage, provided such amendments satisfy the requirements laid out in Section 59 of the Patents Act, 1970.

Upon examining the auxiliary claims proposed by the Appellant, the Court found them to be compliant with Section 59, noting that the amendments were in the nature of an explanation and disclaimer of the original claims.

The Court allowed the amendment and remanded the matter to the Patent Office for fresh examination taking on record the amended claims.