Even if novel, an invention is not patentable if its technical teaching would or could have been discovered in due course by a person with average skills in the respective field. In United States practice, for example, courts applying the non-obviousness standard (the U.S., equivalent to inventive step) undertake a three-step factual inquiry, examining:
(1) the scope and content of the prior art to which the invention pertains;
(2) the differences between the prior art and the claims at issue;
(3) the level of ordinary skill in the pertinent art.
Courts then make a final determination of non-obviousness by deciding whether a person of ordinary skill could bridge the differences between the prior art and the claims at issue given the relevant prior art89. Though sometimes difficult to apply, the inventive step or non-obviousness requirement is critical to prevent the granting of patents on trivial developments.
89See, e.g., Dratler., 1999, §2.03.
The inventive step is often evaluated by considering the “unexpected” or “surprising” effect of the claimed invention. U.S. courts, however, currently reject this approach and stress that patentable inventions may result from either painstaking research, slow trial and error, or serendipity90.
Many countries’ case law holds that there is no inventive step whenever it would be obvious - for a person with average skills - to test new matter with a significant likelihood of success. In the United States, the existence of an inventive step in relation to chemical compounds has been judged by taking into account the structural similarity between the claimed and the prior art compounds, the prior art suggestion or motivation to make the new compound, and the obviousness of the method of making the claimed compound91.
91 However, as mentioned before, in re Deuel (1995) these criteria were relaxed. The patenting of gene sequences has been allowed despite that the sequencing of genes has become a standard technique.
As in the case of novelty, national laws may be more or less stringent in evaluating inventive step or “non-obviousness”. Moreover, in any domestic legal system, courts may elevate or relax the inventive step standard at different intervals in response to either prevailing attitudes towards competition, the perception of a need to protect new technologies (such as computer programmes and biotechnological inventions), or the availability (or lack thereof) of alternative forms of protection in unfair competition laws, utility model laws, or the like.
In establishing the existence of inventive step, it is generally necessary to consider not only the knowledge derived from a single prior document, but also the combined knowledge of existing literature, patent documents and other prior art. However, current U.S. practice disfavours such an approach and holds that “the subject matter of a claim is not rendered obvious by prior art unless there is some specific suggestion or teaching in the prior art that points the way to it”92.
92 See, e.g., Dratler, op.cit.
In the chemical and pharmaceutical field, there is often a close structural relationship between a compound which is claimed as new and inventive, and known compounds, such as salts of acids, bases, isomers, and homologues. In these cases it may be often deemed obvious to try the new compound, thus leading to its non-patentability. The EPO, for instance, has taken the view that the fact that certain advantages were predictable made it obvious to prepare a new compound93. In the United States, by contrast, the presence of a predictable advantage is not deemed sufficient to exclude patentability94.
93 Technical Board of Appeal, T 154/82, IPD 7031.
94 See, e.g., Grubb, 1999, p. 195-196.
The TRIPs Agreement is not specific with respect to the issue of inventive step. Article 27.1 establishes that patents shall be granted to protect inventions which “involve an inventive step” and, in a footnote, it allows Member countries to interpret “inventive step” as synonymous with “non-obvious”.
There is no agreement to harmonize the standard of inventive step/nonobviousness in practice. This suggests that developing countries may be well advised to consult and coordinate on this issue, possibly through their regional organizations.