The Standing Committee on the law of patents (SCP) is a Committee established by WIPO in 1998 with the purpose of drafting a Substantive Patent Law Harmonization Treaty (SPLT). Today, it has become the only Multilateral Patent Forum, where all kinds of discussions on patent related issues take place.

“Quality of patents” is one of the topics that have been discussed for ten years. Within this broad issue, for many years the Spanish Delegation insisted on the elaboration of studies on the assessment of inventive step, taking into account information from all over the world, whenever possible. With that purpose Spain submitted the following proposals:

SCP/19/5 Proposal of the Delegation of Spain for the improvement of understanding of the requirement of inventive step

SCP/24/3 Proposal of the Delegation of Spain for additional studies on the assessment of inventive step

Which have brought about the following documents drafted by the Secretariat of the Committee:

SCP/22/3 Study on Inventive Step

SCP/28/4 Additional study on inventive step (part I)

SCP/29/4 Additional study on inventive step (part II)

The last document, recently published (SCP/30/4 Additional study on inventive step – part III) is devoted to the assessment of inventive step in the chemical sector. As its introduction says, the guidance provided by the study may be considered particularly useful in the chemistry field, because art of chemistry may be characterized by its experimental nature. Research outcomes in the chemistry sector are less predictable, in comparison to electronic or mechanical field. For example, it is not always easy to predict technical effects of a chemical compound only from its structure, and thus the technical effects need to be verified and confirmed by experimental data.

I would like to highlight those aspects which I consider to be the most relevant ones in the various points that have been analyzed in the report:

Claimed invention as a Whole

The existence of broad claims is a common problem in the chemical sector. There is consensus that technical problems could only be considered in the assessment of inventive step if it is successfully solved by all the claimed compounds, and not some of them. This is especially important in the so-called Markush claims (Claims known for encompassing a large number of alternatives). A given technical effect that distinguishes the claimed inventions from prior art should reside in all compounds covered by such a claim.

  • Product and its Manufacturing Process
  • Prior art references without disclosure of a manufacturing method of a claimed compound

There are cases where some compounds are not novel and obvious but the absence of a known or obvious process for making the claimed compounds overcomes the presumption that the compounds are obvious based on the close structural relationship between the claimed compounds and the prior art compounds. At the European Patent Office there have been cases where it has been said that even if a product that appeared obvious per se, it may be considered non-obvious and be claimable as such, if there is no known method in the art to make it and the claimed methods for its preparation are the first to produce it and do so in an inventive manner (T1195/00).

  • Analogy process

In numerous countries, the procedures that bring about new products and which involve inventive step can be patented. Some examples are cited: Argentina, Brazil, Germany and the European Patent Office.

  • Prior Art Citation without Disclosure of The Particular Property or Use of the Claimed Compound

There is consensus that for a certain compound to be cited as prior art, the particular property or use of the compound relevant to the problem must be disclosed.

  • Obvious to try – Expectation of Success

In some jurisdictions, one of the factors that may be taken into account for the assessment of inventive step is whether a person skilled in the art, equipped with the common general knowledge and prior art knowledge, would obviously think of carrying out certain steps with a reasonable expectation of success and would be led to the claimed invention (obvious to try). Examples from Australia, China, India and the United Kingdom are provided.

The Manual of Patent Examining Procedure from the USPTO illustrates several court cases in this regard:

  • Choice of one salt from the limited number of candidates.
  • Not obvious to try because of many options (closest prior art teaches away)
  • Unexpected discovery of new property without any hint.
  • Prior art leads to a small number of options to try.
  • Chemical Compounds:  Structure and Property

In general, to assess the inventive step of a new chemical compound, it is necessary not only to study the similarity of the structure of other compounds but also the predictability of the properties.

The report provides examples from China, Germany, Korea, the Russian Federation and the USA.

  • Isomers, including enantiomers

Isomers are molecules with identical chemical formulae, but having distinct structures. There are several types:

Structural isomers: The same molecular formula but different bonding patterns and atomic organization.

Stereoisomers: They have the same bond structure, but the geometrical positioning of atoms and functional groups in space differs. Enantiomers is one of stereoisomers that are mirror images of each other. In general, enantiomers have identical chemical and physical properties except for their ability to rotate plane-polarized light by equal amounts but in opposite directions. Chemical synthesis of enantiomeric substances produces racemic mixture (racemate), which contains equal parts of (+) and (-) enantiomers. It is not rare that one of the enantiomers have desired pharmacological property, while the other enantiomer is less active, inactive, or sometimes having adverse effects.

The assessment of inventive step with respect to inventions on one specific enantiomeric (pure enantiomer) boils down to a question as to whether it was obvious for a person in the art to invent such a pure enantiomer, based on the prior art, including the common general knowledge.

Depending on the country there are different practices:

Argentina establishes that enantiomers are not patentable. However, a patent could be obtained for processes for the production of individual enantiomers. In Australia, enantiomers can be patented if the isomer is not prepared by routine separation techniques. In Brazil, when the purpose of the prior art compound is known, there is an expectation that the pure stereoisomer of this compound should have this same purpose. In Philippines, enantiomers can be patented if the effects provided by the enantiomers are unexpected. Something similar happens in Korea. In the UK enantiomers will be patentable if they cannot be straightforwardly obtained by standard resolution/separation techniques. Regarding the USA very detailed examples are provided but the key to their patentability seems to be whether unexpected results are achieved or not.

  • Esters, Salts, N-oxides and ethers

With regard to the new compounds that are structurally similar, there are some differences, depending on the country:

In Argentina, these compounds are not patentable, in general. In Brazil, its guidelines state that the mere description of a salt/N-oxide/ester/ether alternative of a known compound, which is devoid of any non-obvious property or an unexpected technical effect relative to the prior art, does not represent inventive step. As for India, an example is shown where a mere conversion to monoester of a known compound with an anticipated effect does not involve inventive step.

  • Polymorphic Forms and Crystalline

Polymorphism is an inherent property of the solid state of drugs used in the pharmaceutical industry. Its patentability varies according to each country:

In Argentina, Brazil and Costa Rica, the key is whether those crystalline forms produce unexpected and surprising effects, so generally they are not patentable. Something similar could be said from the practice in Korea, United Kingdom and the European Patent Office.

  • Combination and Synergy

In Argentina, claims for combinations of known active principles in practical terms are equivalent to claims for medical treatment, for which patentability is excluded. In most countries: Brazil, Philippines, United Kingdom, the USA, and the European Patent Office among others, it is the presence of an unexpected technical effect that makes them patentable.

  • Dosage Regime and Formulations

Argentina considera como no obvia la preparación de nuevas formulaciones, en general. La dosificación se asimila a métodos de tratamiento y por tanto no patentables.

En otros países como Filipinas y Corea la clave estará en la obtención de efectos inesperados. En el Reino Unido se permiten las reivindicaciones de segundo uso médico caracterizadas por el régimen de dosificación, pero salvo casos muy concretos, que por ejemplo superen algún tipo de perjuicio, no son patentables. Se proporcionan ejemplos abundantes sobre la cuestión en el Reino Unido y también en los EE. UU.

. Particle size

An example from the examination guidelines of the Indian Patent Office is provided. A mere change of prior art in its particle size with anticipated effects does not involve inventive step.

  • New Use of Known Substance

Brazil has provided information about those aspects that must be taken into account when the requirement of inventive step is evaluated in these inventions:

  • The mechanism of action of the compound involved in the new use should not be inferred from its mechanism of action for the medical use already revealed in the prior art.
  • The new use should refer to the treatment of a disease whose etiology is different from that of the disease related to the use revealed in the prior art.
  • The new use cannot be inferred from the structure-activity relationship of the drug in comparison with structurally related molecules, i.e., from structural analogy with other compounds that present the same activity currently claimed and already revealed in the prior art.
  • The new use cannot be inferred from the revelation of known adverse effects of the prior art for the drug in question.
  • The new use cannot be inferred from the use of the compound for the treatment of a disease already revealed in the state of the art, even if the claimed use refers to a different disease.

Other issues dealt with are catalysts, intermediates, selection inventions and ranges, with numerous examples.

I’d like to devote more time to the so called Markush claims in this summary. Markush claims have always been a controversial issue in this Committee; least developed and developing countries have always insisted that their patentability be studied and Group B (most developed countries) have always expressed their opposition to those studies adamantly.

After reading the section on Markush claims, it can be inferred that the problems those claims usually show are closely linked to the assessment of inventive step, where the same rules apply as in other chemical cases.

Paragraph 195 states that such claims are accepted in many countries, as long as the presence of a high number of alternatives does not make the obscure or difficult to understand.

The problem often lies in the fact that a person skilled in the art is not able to establish the scope of the claimed invention. It is not unusual for those claims to lack clarity, concision or not to be supported by description, or to present lack of sufficiency of disclosure and also lack of unity of invention.


This detailed and thorough report, full of examples is really suited to put an end to the series of studies on inventive step carried out by the Secretariat of the Committee, following the Spanish proposal.

En español


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