Introduction

Genus-species patent applications are commonly found in the field of pharmaceutical domain. These applications are not only limited to the said domain but are also found in other domains as well such as engineering and the likes. These patent applications share relation of parent-child, wherein the genus patent application has broad coverage of an invention and species patent application has specific coverage. This article in detail discusses about the Genus-Species patent applications in pharmaceutical domain and their patentability requirements in India.

Genus-Species patent applications and their patentability criteria

It is a common drafting practice that claims of the patent applications in the pharmaceutical domain pertaining to a new compound or molecule are drafted in the Markush format. The Markush type claim is defined as a broad or generic claim that refers to a chemical structure of a compound with a plurality of functionally equivalent chemical groups in one or more parts of the compound, as per the Guidelines for Examination of Indian Patent Applications in the field of Pharmaceuticals, October 2014.

Further, it is noted that a patent application covering "n" number of compounds in Markush claims are often termed as "Genus" application. On the other hand, the patent application having specific compounds that may be covered by the Markush claims of Genus patent application are either termed as species patent application or selection patent application.

For examining these applications, there is no separate provision in the Indian Patent law but the patentability criteria for examining these applications is same as it is for other patent applications. These applications need to be novel, inventive, and industrially applicable and should fall out of few exclusions to patentability as mentioned in the Section 3 and Section 4 of the Patents Act, 1970. Specifically, Section 3(d) of the Patents Act is most often applied to these category of applications.

As mentioned-above, there is no separate provision to examine Genus-species applications, however the Guidelines for Examination of Patent Applications in the field of Pharmaceuticals, October 2014, in point 7.2, discloses the provision of assessing novelty of Marksuh type claims. It states that the generic disclosure does not take away novelty of specific disclosure. Therefore, while assessing novelty of species patent application over Genus patent application, it is imperative to determine whether the species is explicitly disclosed in the Genus Patent and whether such disclosure is enabling in nature. The Guidelines also states that if a disclosure is so implicit in the prior art that it leaves a doubt in the mind of the examiner, a novelty objection can be imposed. Further, in most instances implicit disclosure in the prior Genus application might not be prejudicial to novelty of the invention, however, it can still be a motivating disclosure and may be examined for inventive step (of the Species Patent application).

In regard to judging the inventiveness of the Genus-species patent applications, another criteria noted from the precedents is that cherry-picking of substituents from multiple prior art documents without showing what would motivate the person skilled in the art to cherry pick, is impermissible in obviousness or inventive step analysis. (Merck Sharp and Dohme Corporation vs Glenmark Pharmaceuticals, 2015 (64) PTC 417 (DEL); Bristol-Myers Squibb vs BDR Pharmaceuticals International Pvt. Ltd., CS (COMM) 27/2020 (MANU/DE/0299/2020); FMC Corporation & ANR vs Natco Pharma Limited., CS (COMM) 69/2021).

Further, the IPAB in the Novartis Gilvec case (TA/1 to 5/2007/ PT/CH, 2009) has provided minimum patentability requirements for a species patent application as outlined below:

"1.Whether there is any statement in the specification where the nature of the invention concerns with some kind of selection.

2. Whether the selection is from a class of substances which is already generally known.

3. Whether the selected substance is new.

4. Whether the selection is a result of any research by human intervention and ingenuity opposed to mere verifications.

5. Whether the selection is unexpected or unpredictable.

6. Whether the selected substance possesses any unexpected and advantageous property."

Most often issue that is encountered while examining the novelty and inventive step of species patent application, be at prosecution stage or litigation stage, is the interpretation of what compounds are "covered" by the Genus patent application and what compounds are "disclosed" by the Genus patent application. Let us thus decode, the dichotomy of the "coverage" and "disclosure" of the compounds based on the precedents:

Coverage–Disclosure Dichotomy

There are few judgements, which are taken as a guiding law for interpreting the "coverage" and "disclosure" of the compounds in Genus-species patent applications. Based on these precedents, the term "coverage" may be implied as covering a compound that has not been particularly exemplified in any of the embodiments of the specification. The term "disclosure" may be denoted as a particular or a group of compound(s) either given as is in any of the embodiments of the specification or is explicitly exemplified.

The Supreme Court of India in the Novartis Gilvec case (Novartis Ag vs Union Of India & Ors-Civil Appeal Nos. 2706-2716 OF 2013), rejected the Appellant's argument that the scope of coverage is much wider than what is disclosed in the specification of the patent application. The Court observed that there cannot be vast gap between "disclosure" and "coverage" under a patent and, therefore, via clever drafting, a patentee cannot claim that the Genus patent has not disclosed the compound of the species patent even though the compound is covered by the Genus patent. Therefore, this decision blurred the fine line between "coverage" and "disclosure" equating them to be one and the same. This decision has provided a light to a grey area in examining "covered" and "disclosed" compounds and has paved the path to examine Genus-species patent applications on similar lines, but, of course, conclusions varied based on case to case basis.

Further, in Astrazeneca v. Emcure & MSN Labs (CS (COMM) 561/2019), the Delhi High Court (HC) has interpreted the Supreme Court's analysis of the Novartis Gilvec case as an acknowledgement that the scope of the patent should be determined from the intrinsic worth of invention, thereby favoring the plaintiffs. However, the Delhi HC has also observed that Supreme Court in Novartis case, did not shunt the possibility of patenting species patents.

In another recent judgement of FMC Corporation & ANR vs Natco Pharma Limited., (CS(COMM) 69/2021), it was noted that the Plaintiff argued that the product in question was one of the compounds covered by the Markush Claim of the Genus Patent but it is not possible for a skilled person to synthesize the same without creativity and imagination. The defendant relied on the Supreme Court's judgement in Novartis case on coverage and disclosure. However, the Delhi HC observed that though the Markush claims cover the product in question a detailed scrutiny of the Genus patent does not teach the product claimed in species Patent.

Additionally, in the recent landmark decision of the Delhi HC, Astrazeneca Ab & anr vs. Intas Pharmaceuticals Limited & ors, the Delhi HC has provided an interesting observation. The Court held that the fact an infringement suit was filed by the Plaintiff in both the Genus and species patents having the same inventor on record, is a substantial evidence that the compound in question is disclosed under both the Patents. The Court ruled that the compound disclosed in the Genus patent cannot be claimed again in the species patent, without proof of enhanced efficacy and cannot enjoy double patent protection. It may be noted from the said decision that, not only the dichotomy of coverage and disclosure plays an important role in assessing the validity of the Genus and species patents, the motive of ever greening of the patents or monopolizing the market by the plaintiff is also considered as one of the important factors while determining the success of the infringement suits in favor of the plaintiffs.

Infringements suits regarding Genus-species patents

It is observed that the Patentee of Genus patent mostly file the infringement suits. It is because the species patents are usually owned by the owner/applicant/patentee of the genus patents itself and not by any other third party and thus, resulting into ever greening the product or monopolizing the market by the patentee. This section lists out few plausible reasons as to why the species patent are only filed by the owner of the Genus patent, such reasons are as follows:

One of the reasons could be the research and development in the pharmaceutical industry is never-ending, therefore, upon filing a Genus patent application for a particular set of compounds, the scientists keep continuing their research on the compounds belonging to the same family that is covered in the Genus patent application. As a result of such continued research, the researchers/scientists come up with the most pharmaceutically suitable specific compound that shows unexpected advantage and are more effective over other compounds of the same family, which is covered in the Genus application, thus, protecting the said compound in a new patent application that are often termed as a species patent application. Further, another possibility could be extending the patent term by filing species application as part of a business strategy and should not be ruled out when the validity of the species patents is in question.

Another question is why the third party applicants do not file such species patent applications or what can happen if the third party file such species application. The reason of not filing species patent applications could be because of unclear guidance on the species patents or blurred line between covered and disclosed compounds. They fear on investing a huge amount of money in developing and patenting a specific compound, which is disclosed/covered in the Genus patent owned by another patentee, as litigating the infringement suits may lead to huge expenditure in case the said suit is filed by the patentee of the genus patent. Also, continuing research on the compounds belonging to the family of developed compounds takes less time than starting scratch experiments by the third-party.

Further, what could happen if the third party file such species application, it may be assumed that in such cases, most likely the third-party applicant may face infringement suits by the owner of Genus patent that may lead to huge expenditure in terms of time, efforts, and money on fighting such suits, which can be diverted to developing some new compound. However, such scenario is not encountered yet, therefore, it would be interesting to see how such applications would be examined or litigated.

Conclusion

India has seen an increase in the pharmaceutical patent litigations, in the last few years that has attracted global attention towards the Indian pharmaceutical market. These suits are mostly concerned with the infringement of Genus patent given the species matter.

As also mentioned previously, there is no guidance from the Indian Patent Office on interpreting the terms "coverage" or "disclosure," and the judgments on these applications are varied. The prosecution and litigation involved in these applications require extra efforts in assessing their validity. The coverage-disclosure and ever greening have become the factors in determining the validity and success in infringement suits for the plaintiff. Therefore, we have to rely on the judgments of the Courts in India and guidelines issued on the subject by the Patent Office to examine the validity of such genus-species patent applications and to draft such patent applications. Although, more clarity on the subject is much desired.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.