Divide and conquer the winning patent strategy

In the recent case of Novartis AG v Controller of Patents, the Delhi High Court allowed an appeal against the Controller’s refusal of an application for division under section 16 of the Patents Act, 1970 (act). The decision provided clarity over the conditions that must exist for the section to apply. It explained the plurality of inventions as against the single inventive concept of section 10(5).

Patent application for the treatment of dry eye disease, including 56 claims, were filed in 2007 covering a skeletal chemical structure. The Patent Office’s first examination report (FER) in 2013 found a plurality of distinct inventions in the claims. The appellant amended the claims and restricted them to three specific chemical compounds. The parent application as amended was granted in 2017.

After the amendment of the parent application but before its grant, the appellant filed an application for division in 2014, with 26 claims covering a broad range of compounds. The FER of 2018 concluded that claims of division had already been granted in the parent application. In 2019, the appellant amended its claims and limited them to one of the compounds contained in claim 54 of the parent application as originally filed. The Controller of Patents rejected the application for division, concluding the subject matter of the granted parent application and the divisional claims belonged to the same broad class and group of inventions, linked to form a single inventive concept.

The appellant argued that the 2013 FER found few claims with a plurality of inventions contained in the parent application, and the number of substituents in the skeletal structure showed variations not falling within a single inventive concept. Accordingly, the appellant applied for division. The application complied with the requirements of section 16 and the respondent wrongly rejected it.

The respondent’s main objection was duplication. The specific compound claimed in the application for division was part of claim 54 of the parent application as originally filed and for which no plurality was identified in the 2013 FER. The compound claimed in the division was part of the original skeletal chemical structure in the parent application and which was deleted from the parent application. The application for division for the same compound was not maintainable. The court, relying on Boehringer Ingelheim International GmbH v Controller of Patents, held that the divisional application must satisfy all limbs of section 16. The twin requirements for filing an application for division are that the application is in respect of an invention disclosed in the specification already filed in the original application and that there is no duplication of claims in the parent and division specifications.

The court held that the matter forming part of the application for divisional was disclosed in the main core structure of the original parent specification. The main core structure was not, however, in the granted claims in the parent application. The specific compound claimed in the application for division was fully disclosed in the

body of the specification and in the claims as originally filed, but not granted, in the parent application. The first requirement in section 16 was satisfied. The court found that the differences in the compounds derived from variations in main core structure clearly showed that the specific compound in the application for division was not one of those in the granted claims in the parent application. As the main core structure was not retained in the parent, the compound claimed in the division was not held to be covered by the granted claims of the parent application. The second requirement in section 16 was also satisfied.

In rejecting the application for division, the respondent had relied on a lack of therapeutic efficacy under section 3(d) of the act. The court held that the test of therapeutic efficacy did not apply in such applications at the maintainability stage.

The court held that the application for division was capable of success and therefore the Patent Office should re-examine it on its merits for novelty, inventive step and non-patentability. The crux of Boehringer is that the application for division is maintainable only when the claims of the parent application disclose plurality of invention. In upholding this decision, Novartis strengthens twin requirements for such applications. These exemplary decisions of the IP Division of the Delhi High Court well guide quasi-judicial authorities dealing with the intricacies of the act.