One topic that does not die out is with respect to Section 3(d) of the Indian Patents Act. Most of us have witnessed Section 3(d) objection mocking like a silent spectator under paragraphs 3 or 4 of the First Examination Report. The objection gradually moves up places in the further official actions until it takes all that familiar position under paragraph 1. The question remains – how do we break the 3(d) code?

Section 3 of the Act enumerates inventions that are not patentable. Section 3(d) relates to new forms of known substances. The part of the 'Explanation' corresponding to clause (d) of section 3 - "considered to be the same substance, unless they (i.e., derivatives of known substances) differ significantly in properties with regard to efficacy"- reveals a test of patentability with 'enhanced efficacy' as the criteria.

The present study is aimed to provide possible practical solutions to evade or overcome the objection under Section 3(d). We shall focus on possible strategies that may be employed especially in inventions relating to chemical compounds.

While dealing with objections under Section 3(d), we propose that the following four line strategy:

Line 1 – Resist the objection by laying emphasis on novelty, inventive step and industrial applicability of the invention:

It should be noted that Section 3(d) as worded reads: "The mere discovery of ........". Our aim in the first line of defense is to argue that what is being claimed is not a "mere discovery" but an invention.

According to Webster's Revised Unabridged Dictionary, a discovery has been defined as "The action of discovering; exposure to view; laying open; showing", or "that which is discovered; a thing found out, or for the first time ascertained or recognized, as, the properties of the magnet were".

Going by the same source, an invention has been defined as "the act of finding out or inventing; contrivance or construction of that which has not before existed; or "that which is invented; an original contrivance or construction".

Discovery is finding out something which is already occurring in nature. It may be argued that what is being claimed is not a mere discovery but an invention since it did not exist prior to the date of filing of the Patent application. As an example, fire is a discovery since it always occurred in nature. However, an X salt of rosiglitazone is an invention since it did not exist prior to the date of the invention.

Under Indian Patents Act, an invention has been defined as a novel product or process having inventive step and industrial applicability. You may argue that if something satisfies the said criteria, it should be categorized as an invention rather than a mere discovery under Section 3(d).

Line 2: Response to the First Examination Report:

It is advisable that the best argumentation be presented while the objection is still in its nascent stages. A study of the recent case laws suggests that an objection with respect to Section 3(d) can be overcome provided enhanced therapeutic efficacy is established. The second line aims to utilize this explanation.

If an objection with respect to Section 3(d) is raised in the Examination Report, submit the first response early. An early response would give the Examiner sufficient time to study the response vis-à-vis the objections raised. Also, if the Examiner maintains the said objection, it is apparent that the further official action may be issued earlier. This may provide the applicant sufficient time to submit an additional response.

Further, critically evaluate and resist the objection in the first response. Supplement the response with detailed clinical data evidencing enhanced therapeutic efficacy of the claimed compounds over the prior art compound. To top it all, submit an affidavit from a technical expert verifying enhancement in efficacy at this stage itself.

The question here is - what would be considered as 'substantial improvement' while considering the explanation provided under Section 3(d). While the picture is ambiguous, on most occasions a twenty five to thirty percent improvement in therapeutic efficacy is considered substantial by the Examiners.

Further, of late, it has been observed that the Examiners require clinical data for most if not each of the claimed compounds. Therefore, it is advisable that maximum claimed compounds be tested for therapeutic efficacy in clinical data.

From the recent case laws, you may note that the term efficacy under Section 3(d) is with respect to therapeutic efficacy. The question is what should be the case where enhancement is with respect to aspects like flowability, stability and bulk handling of the compound. Unfortunately, the picture is still ambiguous here. Does it essentially mean that we have reached a dead end?

You may note that most compounds, which are subject matter of inventions, are used in therapy. Let us take an example. I say that my salt A is more stable than the compound of the prior art B. While my salt A is 90% intact after three weeks, the compound of prior art is 50% intact after the same time. The Examiner continues to stress on the enhancement of therapeutic efficacy. What if we conduct an experiment wherein fixed amounts of salt A and compound B are first kept on shelf for 3 weeks and then administered to a patient? If my compound A is stable over the shelf, won't it be more viable at the end of three weeks and therefore more effective therapeutically? Questions like these are yet to be answered.

Line 3 – Revision of the claims:

If the arguments referred in the preceding paragraphs are not acceptable to the Examiner, you may consider revising the claims in accordance with either of the following routes. It has to be noted that the revisions should be supported by the specification and the original set of claims.

Route 1: Direct them to a process of preparation.

Revise the claims by directing them to a process of preparation. Under Indian practice a single application claim is allowable in a Patent application. Therefore, a single compound claim as an application claim of the process may still be allowable.

Route 2: Direct them to a composition

Revise the claims to a composition comprising compound along with other active agents and/or adjuvants. However, please note that Indian practice requires that composition be defined in terms of the requisite ratio/weight percentages of components. You may therefore be required to disclose weight percentages of the components in the main composition claim.

Line 4 – Divisional applications:

Under the Indian Patents Act, an Applicant may file divisional applications under two conditions: on its own motion (suo moto) or to overcome the Examiner's objection with respect to plurality of distinct inventions.

Therefore, if the chances of allowance of the compound claims appear bleak, a divisional application may be submitted. Further, while submitting a divisional application, it is advisable that the subject matter of compound claims be claimed in the divisional application. The parent application may then be allowed to proceed to grant with the secondary process or composition claims.

This approach may help in keeping the compound claims pending, while giving the Applicant additional time to conduct clinical trials and prepare technical affidavits, which may be required during prosecution of the divisional application.

The topic is often discussed and the issue does not seem to die out. While we have endeavored putting together certain possible solutions, there are still others that could be better explored and practiced. All the same the examiners and the applicants should, together, not allow the ambiguity in law to jeopardize the essence of patenting, more so in India where the need for innovation and technology is so progressively vibrant. Well-drafted patents, carefully analyzed laws and well thought decisions could go a long way in safeguarding both public and private interests.

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.