Selection patents can be said as those patents which claim particular compounds to be individually new but as falling within an earlier disclosure of a broader group of compounds for which protection is already claimed. The law regarding selection patents is essentially developed to protect the original inventor, as regards to the invention he has made, and to encourage other inventors in the field to discover fresh advantages and to treat the discovery of such advantages as inherent in selected members of the group or class as a patentable invention.
The Indian Patent framework does not itself define selection patents. But, for the selection patent in India to be validated, they must satisfy the criteria laid down in section 3(d) of the Patent Act. To overcome the objections under section 3(d), it is essential for selection patents to show that a new form of a known substance resulted in the enhancement of known efficacy. Similarly, the Indian Patent Office (IPO), in its Manual of Patent Office Practice and Procedure (2019), in relation to the explanation under novelty, states that:
- A generic disclosure in the prior art may not necessarily take away the novelty of a specific disclosure. For instance, a metal spring may not take away the novelty of a copper spring.
- A specific disclosure in the prior art takes away the novelty of a generic disclosure. For instance, a copper spring takes away the novelty of a metal spring.
Thus, the IPO Manual suggests that the Patent Office will not categorically refuse selection patents for novelty considerations but rather closely examine generic and specific disclosures while examining its validity.
Further, the Guidelines on the patentability of pharmaceutical inventions in India clarifies certain positions with respect to the selection patents. According to which, the broad generic patent claims are drafted covering a family of a large number of possible compounds. Generally called ‘Markush claims’, they refer to a chemical structure with a plurality of functionally equivalent chemical groups in one or more parts of the compound. The Markush claims are drafted to obtain a wide scope of protection encompassing many compounds whose properties might not have been tested but only theoretically inferred from the equivalence with other compounds within the claim. Confusions with regard to novelty, non-obviousness, and industrial applicability of a group of compounds covered within the said Markush formula and questions of sufficiency and plurality of distinct group of inventions surrounding such claims often pertains.
It also provides that while examining above said Markush claims, the complete specification should be critically examined whether: (i) it discloses best representatives, as known to the applicant, of the possible embodiments;(ii) such embodiments share a common use or property; (iii) such possible embodiments share common structure; (iv) physical and/ or chemical properties of best representatives of such embodiments known to the applicant are disclosed; (v) test conducted for the representatives of such embodiments known to the applicant is provided; (vi) in case of product claims at least one process for preparing the compounds has been disclosed enabling the whole scope of the invention. Moreover, if any one of (i) to (vi) are not met, such a Markush claims may be objected depending upon the circumstances of the application so examined under ‘Unity of invention’ and insufficiency of disclosure suitably.
In the case of selection patents, the incentives are much different in comparison to others. Depending on whether a selection patents is patentable or not, the party who has made the selection receives either nothing at all or part of the value of the improved effect. The way in which the statute and rules of jurisdiction are applied to determine claim scope is itself very important. If a doctrine or any other approach that construes claim scope beyond its literal limits is applied too liberally, then there is a risk that novelty and obviousness assessments become indistinguishable. Thus, a proper interpretation of statute and harmonising it the intent of the legislatures becomes important.