India: Selection patents- Hon’ble High Court’s opinions on ‘coverage’ and ‘disclosure’

Introduction

Selection patents continue to be a grey-area in the Indian Patent regime. Selection inventions involve the selection of one or more embodiments such as individual elements, sub-ranges or chemical groups from a larger known set or ranges or compounds disclosed in the prior art. Selection patent is not defined under the Indian Patents Act and cover various fields and technological areas such as chemical, pharmaceutical and metallurgy etc.

In recent cases, the High Courts in India have considered the issues related to selection patents, specifically in respect of selection/species patents and genus/prior patents in the pharmaceutical domain. The Hon’ble court in these cases did not lay down any conclusive opinion, however, these decisions can be referred by the applicant(s) for the assessment of such applications in India.

The Hon’ble Court in Astrazeneca Ab & anr. vs. Intas Pharmaceuticals Ltd., 2021[i] while dealing with a product comprising the compound ‘Dapagliflozin’ (hereinafter referred to as ‘DAPA’) which is used to treat people suffering from type-II diabetes mellitus observed that the appellants while claiming one invention only i.e., DAPA, are claiming two patents with respect thereto, and alleging infringement of both, by the respondents. The same alone strikes at the very root of the claim of the appellants and disentitles the appellants from any interim relief. Thus, for a patentee to enjoy protection, the rights have to be within the four corners of the statute i.e., the Act and there are no rights independently thereof or inherent or common law rights of an inventor or patentee.

It was further observed that when the inventor is the same, the tests cannot be in the context of ‘person ordinarily skilled in the art’ but have to be of the ‘person in the know’. The enquiry, in such a situation, has to be guided by, whether the inventor, while writing the first patent (genus patent), knew of the invention claimed in the subsequent patent (species patent).

The distinction between ‘coverage’ and ‘disclosure’

The question of whether there exists a difference between ‘coverage’ and ‘disclosure’ is a contentious issue in selection patents. The Hon’ble Court is proactively dealing with the issue in hand.

In Novartis Ag & anr vs. Natco Pharma Limited, 2023[ii], while dealing with the compound ‘Certinib’, the plaintiff asserted that coverage is not the same as disclosure and that disclosure in the prior art must be enabling in nature. The Hon’ble Court observed that Ceritinib has not been claimed in any prior art. In fact, ‘Ceritinib’ was not synthesized before the grant of the suit patent through any other patent by any other person, which by itself is a strong indication towards the suit patent having been not disclosed in any prior publication.

The Hon’ble Court endorsed the observation in Pfizer Inc. v. Teva Pharmaceuticals[iii] that “a patent challenger however must demonstrate the selection of a lead compound based on its promising and useful properties, not a hindsight driven search for structurally similar compounds”. The Hon’ble Court observed that no person skilled in the art can, without hindsight analysis and cherry-picking of suggested substitutions, reach the suit patent from the cited prior art. The prior art does not contain the requisite teaching or disclosure, as would enable the person skilled in the art to reach the species patent.

The Hon’ble Court while relying on Novartis[iv] above (different factual circumstances) in Boehringer Ingelheim Pharma Gmbh & Co vs. Excel Drugs and Pharmaceuticals Pvt. Ltd. & Ors., 2023[v] refused to grant an injunction in favour of the patentees, thereby restraining the defendants from selling the drug Linagliptin. It is noteworthy that the Hon’ble Court in this case considered the prosecution history of the patent in admission.

It was asserted by the patentees that Linagliptin was specifically claimed only in the species patent (IN’301) and the same was never claimed in the genus patent (IN’719). Rather, it was merely covered by the Markush structure of the genus patent. The Hon’ble Court took the stand that the patentees cannot be allowed to approbate and reprobate.

It was held that Linagliptin was disclosed, claimed and covered under the genus patent, as well as the suit patent. In terms of a selection patent, it was observed that the selection of optional substitutions or selection of specific substances or compounds after coverage in a prior patent is prohibited in view of the decision in Novartis above.

Recently, the Hon’ble Court in Bayer Healthcare LLC vs. Natco Pharma Limited, 2023[vi] refused to grant an interim injunction against the defendants for IN’207 that covers and claims a molecule known as Regorafenib.

The plaintiff averred that there is a marked difference between ‘coverage’ and ‘disclosure’ in patents. ‘Coverage’ of compounds under the genus patent does not mean that the same have been ‘disclosed’ or that they cannot be protected under a separate patent application.

While relying on the earlier decisions in Novartis AG[vii] and AstraZeneca AB[viii] and the provision under Section 53(4) of the Act, the Hon’ble Court held that on expiry of the term of the patent, the subject matter ‘covered’ by the said patent shall not be entitled to any protection. Attempts of ever-greening of the patent are to be discouraged and denounced. It is only a truly new product or process involving an inventive step and capable of industrial application, that would be entitled to protection under a subsequent patent.

The Hon’ble Court observed that the plaintiff having admitted that the suit patent is covered by the genus patent, though qualifying such admission by use of the word ‘technically’, whose term has admittedly expired, at least prima facie is not entitled to an interim injunction order.

It is important to note that public interest and the huge disparity between the price of the product offered by the plaintiff and the defendant for a life-threatening disease, were also considered as relevant factors in this interim order.

Conclusion

In light of the above-mentioned cases, it is notable that the distinction between ‘coverage’ and ‘disclosure’ has been dealt with by diverse views, such as the Boehringer decision above rejecting any distinction between these terms whereas the Novartis decision above accepting the ‘wide gap’ between what is covered and what is disclosed in a patent. Therefore, it is imperative now to include clear provisions or guidelines for the examination of selection patents in the Act. With the constitution of two IP divisions and the developing jurisprudence in India, it looks more promising at present.

[i] FAO(OS) (COMM) 139/2020, CMs No. 28068/2020, 28070/2020 & 32664/2020. Delivered on July 20, 2021 [ii] CS(COMM) 229/2019. Delivered on January 09, 2023 [iii] USA, No. 12-1576 (Fed. Cir. 2014) [iv] Supra 2 [v] CS(COMM) 239/2019 & CCP(O) 82/2019, I.A. 6797/2019, I.A. 9272/2019, I.A. 2042/2020 and I.A. 2044/2020. Delivered on March 29, 2023 [vi] CS(COMM) 343/2019 & I.As. 8878/2019, 9685/2019, 1178/2022. Delivered on July 05, 2023 [vii] [2013] 13 S.C.R. 148 [viii] Supra 1