Authored By: Abhishek Kumar
National Law University, Delhi
Pharmaceutical patent issues are very complex generally involving the method of evaluating a mix of interrelated factual and legal issues. To put it simply, the main criteria for patenting a drug or a chemical compound are that: (a) it is a new product, (b) it demonstrates a technical improvement over what is already known, (c) it has economic value, (d) it can be used in industry, (e) a person skilled in the art would not find it obvious, (f) no prior art has anticipated it, (g) it has not been in use at any time before the filing date of the complete specification, (h) it is not just the discovery of a scientific principle or the formulation of an abstract theory, (i) it is not merely a new form of a known substance without the enhancement of the known efficacy of that substance, and (j) it is not excluded from patentability under Section 3 of the Patents Act 1970.
Pharmaceutical, chemical and biotechnology patents generally rely on two main types of claims: genus patents and species patents. A genus claim refers to patent protection for a broader class or family of related chemical compounds rather than a single defined compound. In contrast, a species claim relates to a single specific, concrete and clearly identifiable chemical compound, thus excluding other derivatives within the same chemical family. To put it simply chemically a genus claim might be acid while a species claim would be sulphuric acid. These patent applications have a parent-child relationship with the genus application being a broad one covering a large set of compounds and the species application narrower often focused on an individually optimised compound.
Patents Act 1970 (the Act) Sections 3(d) and Section 3(e) require that patent authorities diligently ensure that patent holders do not abuse the system by repeatedly patenting trivial changes of the same drug or invention. This kind of misuse of the patent system is popularly known as patent evergreening. Such safeguards in the statute have effectively created a strong shield against granting patents to substances which are already existing or known.
Recently, several decisions of the Delhi High Court have carefully analysed the complex issue of the coexistence of genus and species patents. The Indian Patents Act does not contain a direct answer to this issue. However, the problem has come up time and again and is generally referred to as the “Coverage and Disclosure Dichotomy”. At its simplest it means that the exclusive rights granted by a patent are limited to the subject matter that is explicitly claimed and disclosed in the patent document.
India’s patent system is primarily based on economic principles. These principles are the foundation of the patent system’s fundamental quid-pro-quo where limited monopoly rights are granted to the patentee in exchange for the patentee’s full unveiling of the invention. Therefore, if a patentee enjoys the monopoly rights without such obligatory disclosure it goes against the basic rationale that underlies this finely balanced exchange mechanism.
What is Disclosure?
Giving the patent to one of the competing parties requires fundamentally that the subject of the patent claim must be truly new. This entails the question and answer whether the earlier publication certainly takes away the novelty of the patent’s subject matter or not. Court decisions provide a pointer to what is meant by disclosure in the case of genus/species type patent specifications. They say that it means the clear statement of a particular substance or group of substances whether mentioned in the claims or worked out in the description.
Recently, in a 3-member bench decision dated September 29, 2020 the Intellectual Property Appellate Board (IPAB) has expressed its understanding of prior disclosure. IPAB set aside the revocation order of the Delhi Deputy Controller of the patent of Novartis for the cancer drug Ceritinib which was being challenged by Natco Pharma’s post-grant opposition on the grounds of lack of novelty and inventive step under Section 3(d) of the Act. Their lead argument was that the drug was anticipated through Markush structures of earlier genus patents as per the Guidelines for Examination of Patent Applications in the Field of Pharmaceuticals a Markush structure is a chemical compound with numerous functionally equivalent chemical groups in one or more parts of the compound which normally means that the claims of the compound are very broad and cover all the congeners of the chemical lineage.
In line with Novartis, the Court of Intellectual Property reiterated that Ceritinib was not “anticipated” based on prior patents since it was not disclosed in any of the claims or specifications of those patents. Besides, the prior art is considered as “disclosing” only if it provides sufficient details enabling a person skilled in the art to reproduce the invention without infringing the patent in suit as stated by the Tribunal. The Tribunal also rejected listing in the Orange Book for Patent Term Extensions (PTE) under U.S. law as a form of disclosure, since PTE requirements significantly differ from patent law principles of novelty and inventiveness, which should not be considered as the same thing.
Orange Book or “Approved Drug Products with Therapeutic Equivalence Evaluations” officially, is a register of drugs approved by the FDA as safe and effective in the United States. Being listed in the publication only means that a compound is read on or contained within the scope of a parent genus patent without implying the fulfillment of novelty or inventive step levels. Since Indian law has no relevance to the other countries, Orange Book is not considered as a basis for making the novelty or inventiveness determination in India. Lastly, the Board rejected mosaicking that is putting together different publications to show lack of novelty, stating that the anticipatory disclosure exists only in one rather than several prior documents that have been combined without the demonstration of linkage justifying unitary construction.
Although the Patents Act does not contain a specific provision for genus and species patent filings, the patentability of such applications will be judged by the same criteria that are used for normal patent applications. In fact, paragraph 7.2 of the Guidelines for Examination of Patent Applications in the Field of Pharmaceuticals provides the standard for novelty in genus/species claims stating quite explicitly that a generic disclosure in the prior art may not necessarily take away the novelty of a specific disclosure. In order to explain this legal dilemma, it helps to turn to the chemistry example: the key question when defining the claim scope is whether prior genus disclosure of acids excludes a later species claim to sulphuric acid or the other way around depending on whether the species is specifically identified within the genus disclosure.
Since the Act lacks statutory definitions of “Genus” or “Species” one may turn to the Act’s disclosure provisions for interpretative guidance. Section 7 regulates the application form and amongst other things states that each application must only relate to one invention (Section 7(1)) and it must be accompanied by a provisional or complete specification (Section 7(4)). On the other hand, Section 10 details the contents of a complete specification, requiring a comprehensive description of the invention, definition of the claim boundaries, a brief outline of the method and disclosure of the best method (the “enablement” or sufficiency requirement).
Section 10(5) limits claims to the content of the specification, linking them to a single invention or a cluster of closely related inventive concepts. Section 25 allows oppositions if the specifications are found to be lacking or unclear in explaining the invention or its mode of operation. The forthcoming Part II of this Article will shortly unravel species patent principles of grant and investigate whether a coverage without disclosure in a prior genus patent negates patentability.
Principles for Species Patent Grants
The Delhi High Court in AstraZeneca AB v. Torrent Pharms. Ltd. case heavily relied on the famous In re I.G. Farbenindustrie A.G. decision in setting the fundamental principles that a selection (species) patent must be based on. These principles are (1) the selected compounds must bring about a major advantage, (2) this advantage should be common to all the compounds in the selection, (3) the selection must possess a distinctive character that is outside of the inherent properties of the individual members of the selection, (4) the substantial or unexpected advantage must be clearly identified in the patent specification. Therefore, a species compound which is covered by but not disclosed in a prior Markush genus claim may still be patentable.
Patentability Despite Genus Coverage
In the Torrent Pharma case, the Delhi High Court not only affirmed the Supreme Court’s decision in Novartis AG v. Union of India, but also went a step further by rejecting any blanket ban domestic or foreign against dual genus (Markush) and species patents where the latter is not disclosed in the specific genus. To explain by analogy, a genus claims to “acids” leaves “sulphuric acid” patentable provided the latter has not been explicitly mentioned before.
In AstraZeneca AB v. Intas Pharms. Ltd. the Delhi High Court on the other hand, denied AstraZenecas request for an injunction against Intas and Alkem, stating that putting forward two different ways of infringing the same patent cannot be read as a disclosure of that patent. The court referring to Section 10(4) held that it was “incongruous” for a patentee to insist on non-disclosure even though there were two suits comparison of specifications further showed the species patent didn’t advance over the genus patent and that there was a risk of revocation under Section 64(1)(e) for prior publication/lack of novelty. In contrast to the above, in AstraZeneca AB v. Emcure Pharms. Ltd. the Delhi High Court, contrary to the general principle of patent segmentation upheld the enforcement of species patent while acknowledging the pre existence of genus patent where the drug came into existence under the species claims, thereby departing from earlier benches and the principles of Novartis to some extent. The court stated that Novartis allowed the grant of species claims after a genus claim had been issued – this is a forced interpretation, as the Supreme Court rejected any such blanket approval. This decision may lead to a wider coverage-disclosure gap and is a subject of scholarly criticism however Novartis still serves as a guiding light.
Novartis rejected the notion that coverage-disclosure skews leading to grant fundamentals being transgressed. IPAB highlights the adequacy of disclosure as a requirement for the validity of claims. “Disclosure in prior art” means giving a physically tangible example which is different from obviousness – a question of whether a skilled person is able to derive the species from Markush without an inventive step. Common inventorship changes the perspective of obviousness from the “outsider” to the “insider” Novartis still maintains that decisions depend on the factual scenarios in individual cases.
Conclusion
India’s pharmaceutical patent market has been on a roller coaster ride lately, drawing the global community’s eyes to its pharma sector. Most of these patent battles revolve around defendants accused of infringing the … being a species of a genus patent. Because the Patent Office has not provided any official interpretations of important concepts such as “coverage” and “disclosure” it is very difficult to conduct validity testing of patenting charges While the courts have been debating the coverage-disclosure principles for a long time, following the Patent Office’s guidelines in the drafting and scrutiny processes is still relevant. Indeed, coverage disclosure and evergreening are now being used as the main criteria for determining the results of infringement suits. Therefore, there is an immediate need for the Patent Office to provide more clarity on these matters.
