Legal Eagle

Legal Eagle

Promoting clarity and certainty in the patent process

Patent law is one of the most complex and convoluted areas of the law. Greg Kalbaugh, Dr Raj Dave and Christopher K Dorsey work out a usable definition for the ‘efficacy’ requirement in the Indian Patents Act

Having a clear framework to evaluate patent applications is key to ensuring patent quality, and the Indian Patents Act sets forth just such a structure. But in using the term ‘efficacy’ to prevent patenting of seemingly trivial variations of new forms of chemical and pharmaceutical substances, Section 3(d) of the Act remains somewhat ambiguous. This ambiguity arises because the term ‘efficacy’ is foreign to patent law throughout the world, but is a term of art in the unrelated field of drug regulation and approval.

The ‘efficacy’ requirement of Section 3(d) of the Indian Patents Act should not be interpreted as synonymous with therapeutic efficacy; rather, efficacy should be defined in a manner congruent with patent laws worldwide. In other countries, patent laws accomplish the goals of Section 3(d) by requiring patent applicants to show that their invention is not obvious. In the case of chemical and pharmaceutical arts, non-obviousness is proven by showing the new variation yields ‘unexpected results’, which is an objective standard ideally suited for, inter alia, the chemical and pharma arts because the analysis is based on facts and capable of being judged objectively. The factual nature of the unexpected results inquiry provides inherent efficiencies.

Drawing a Line

The ‘efficacy’ test in Section 3(d) of India’s Patent Act possesses some inherent ambiguity. Section 3(d) phrases its limitation on patentability as follows–’the mere discovery of a new form of a substance which does not result in the enhancement of a known efficacy of that substance’ is not an invention. The Act does not, however, define the term ‘efficacy’. Because this particular section applies to pharma and other chemicals, a temptation arises to define ‘efficacy’ synonymously with its usage in drug regulation, where it is a term of art. Succumbing to this temptation ignores the contrast in policy and implementation between the patent laws and the regulations governing drug usage, distribution, and marketing.

The patent system and the drug approval and regulation system serve vastly different purposes and are administered by different agencies. Patent laws are intended to promote technological development and investment in research. In India, the Patent Office is the administrator of the patent system, its primary function being to examine patent applications. By contrast, pharma regulations ensure the suitability of pharma and manage their marketing, usage, and distribution to promote public health and safety. These tasks focus on a substance’s clinical, rather than economic, effect and are administered by the Central Drugs Standard Control Organisation (CDSCO). The Patent Office and CDSCO deal in separate fields and make their decisions based upon vastly different policy imperatives.

The tension between the patent system and the drug regulatory system becomes particularly apparent in two instances. Consider, for example, a new variation of a chemical for which patent protection is sought. This hypothetical chemical possesses substantial utility, but has no pharma effect. Defining ‘efficacy’ in Section 3(d) as ‘therapeutic efficacy’ provides no meaningful insight into the patentability of this hypothetical compound. The same issue arises in the converse situation. A pharma must be therapeutically efficacious to gain regulatory approval, but may be a mere predictable extension of the prior art. Providing patent protection for insubstantial technological advances due solely to demonstrable therapeutic efficacy is contrary to the core purpose of the patent system. Thus, ‘efficacy’ in the Indian Patents Act cannot simply mean ‘therapeutic efficacy’.

An additional significant problem exists in defining the above two terms, even for pharmaceuticals. Many pharmaceuticals are the result of many years of research, trial, and error, so for each patent application claiming an efficacious pharma substance, the prior art often will consist of numerous inefficacious pharma substances. These failed alternatives often are not subjected to clinical testing to verify their lack of efficacy—in some cases because the substances are potentially harmful to humans in treatment. Using ‘therapeutic efficacy’ as a substitute for the ‘efficacy’ requirement in Section 3(d) would force the applicant to perform testing to demonstrate the inferiority of the failed substances just to obtain a patent, potentially at the risk of human health. This result further proves that ‘therapeutic efficacy’ is an unsuitable definition for Section 3(d)’s efficacy requirement.

The ambiguity in Section 3(d) stems in part from the distinction between patentability and obviousness. Whereas a patentability restriction imposes a limitation on the actual subject matter of a patent, an obviousness test prevents obtaining a patent for a simple extension of what is already known.i Due to the historical restrictions on the patentability of chemicals and pharma in India (which earlier allowed process patents), Section 3(d) was enacted as a limitation on patentable subject matter. But, in using an enhanced efficacy test comparing the invention to the state of the art, Section 3(d) is more naturally characterised as an additional obviousness hurdle.

Defining ‘efficacy’

The concern addressed by Section 3(d)’s efficacy requirement is an often-litigated, but well—defined, topic in both the United States and Europe. Section 3(d) anticipates situations where a patent application does not claim a new substance, but rather claims a variation of a known substance. In many cases, engineers and chemists can anticipate that similar substances will have similar uses or respond to modification in similar ways. This situation is of concern because patent laws are designed to reward true innovation, not predictable changes to what is already known. By informing the ‘inventive step’ requirement and Section 3(d) using the framework applied in the United States and Europe, this goal is accomplished.

US patent law imposes a high burden on patent applications claiming modifications or variations of known substances. According to US law, structurally similar compounds are presumed to have similar properties.ii To overcome this presumption, the patent applicant must provide evidence to the contrary. The applicant meets this burden by showing unexpected results.

Proof of unexpected results may have many forms. In every circumstance, the ‘invention (must) exhibit some superior property or advantage that a person of ordinary skill in the relevant art would have found surprising or unexpected.’ iv Putting the test to practice focuses on that unexpected superior property. For example, using the unexpected-results test, an invention is not obvious when a surprising result is achieved via a non-routine modification to one of a group of similar compounds. In this case, the prior art did not tell the inventor which compound to choose; the state of the art did not show the inventor the manner in which the compound should be modified; and most importantly, provided a surprising result. The first two factors provide strong evidence that the compound is not obvious, but the demonstration of unexpected results confirms this conclusion.

By contrast, an invention is obvious where there is a suggestion to chose one particular compound or variation, or if the inventor creates the new form using a known technique to obtain the desired result. Unlike the case above, in this case, the prior art guided the inventor towards the invention and provided an expectation of success. Such an invention is not patentable. A patent must demonstrate the requisite ‘inventive step’, not exist as a mere extension of the state of the art.

To ensure consistent application of the unexpected-results test, the US and the European patent offices instruct their employees regarding its proper application. For example, the US Patent and Trademark Office tells its patent examiners to “consider the number of variables which must be selected or modified, and the nature and significance of the differences between the prior art and the claimed invention.” The European Patent Office provides similar guidance to its examiners.viii In both cases, the unexpected-results test is structured to maximise clarity and consistency during the test for obviousness.

Putting unexpected results test into practice

A substantial advantage of using an unexpected-results test to judge Section 3(d)’s efficacy requirement is the factual nature of the unexpected results analysis. The US and Europe use the unexpected results analysis as an objective inquiry, focusing on facts.

Because the unexpected results test is an objective determination and based in fact, the results are not unique to the patent laws of any particular country. Taking these objective

findings into account increases the efficiency of the Indian Patent Office’s evaluation of pending applications and simultaneously beings the process of granting patents in conformity with prevailing standards worldwide. This efficiency comes at little cost because providing such consideration in no way threatens the sovereignty of the Patent Office.

Using unexpected results, which is an objective standard, to define the ‘efficacy’ requirement of Section 3(d) of the Indian Patents Act is extremely favourable for both the IPO and Indian business interests generally. The unexpected-results test provides certainty and clarity in the patent process and ensures consistent treatment of patent applications in India and other countries. Implementing the test would increase the efficiency of the Patent Act’s Section 3(d) determinations. This framework only enhances the attractiveness of India for investment in chemical and pharmaceutical research, development, and sales. In short, ‘unexpected results’ provides the best framework for clear, consistent determinations of efficacy under Section 3(d).

(Greg Kalbaugh is a Director and Counsel at the US Chamber of Commerce and directs the Global Intellectual Property Centre’s initiatives in India. Dr Raj Davé is a partner at Pillsbury Winthrop Shaw Pittman LLP, focusing on strategic intellectual property counselling. Christopher KK Dorsey is a member of Pillsbury Winthrop Shaw Pittman LLP’s Intellectual Property group.)