outcomes when the inventor tries to obtain patent
protection for the same invention in different coun-
tries. But generally, these three criteria are univer-
sally accepted. Of these, novelty and utility are
usually the easiest criteria to deal with.
Novelty. An invention isnovelifit was not part of
the ‘prior art’ before to the priority date (see below)
of the patent application which claims the inven-
tion. The ‘prior art’ comprises all oral or written
information publicly available before the priority
date of the application. This criterion is essentially
absolute everywhere except in the United States,
where there is a ‘grace period’ of one year within
which one can file a patent application even if the
invention has been earlier divulged either by the
inventor or by another. Novelty is fairly strictly
interpreted; that is, the destruction of novelty
requires a specific prior description of the invention
being claimed. Thus, one can obtain a patent on a
compound even if it is within the scope of the
generic formula in an earlier publication which
teaches multiple substituents on a core structure
but which does not specifically show the now-
claimed compound. To determine novelty one
compares the date of invention (under US law) or
priority filing date with the divulgation date of the
supposed prior art. If the subject matter is the same
and the divulgation date of the publication pre-
cedes the invention/filing date, then the invention
fails the first test and cannot be patented.
In the United States, one further twist on divul-
gation dates is that a US patent is a reference as of
its earliest US filing date. As a US patent applica-
tion used not to be publicly available until the
patent issued and since the allowance of a patent
could be delayed either by a prolonged prosecution
in the Patent Office (which could include appealing
an adverse determination by the Examiner both
within the Patent Office and then to the courts) or
by the filing of one or more continuation applica-
tions, a US patent could become a reference as of
its earliest US filing date many, many years after
said filing date. Such patents (sometimes referred
to as ‘submarine patents’) can be used as weapons
in litigation to invalidate competitors’ patents, the
applications for which were filed after said earliest
filing date. Now that the United States has joined
the rest of the world in publishing applications
18 months after filing, ‘submarine patents’ are
becoming much less of an issue.
Utility. An invention isutileif it has a practical
end use. The requirement can be met by a statement
ofwhat theinvention can be usedfor and how touse
it; for example, ‘This compound is useful for the
treatment of asthma when administered at a dose of
0.1–5.0mg/kg per day’. A more complete teaching
would include modes of administration, dosage
forms, delivery systems and so on. The utility
must be currently available. Although commercial
availability is not necessary, mere assertions such
as ‘these are therapeutic agents’ or ‘they are for
pharmaceutical purposes’ are generally insuffi-
cient. If the asserted utility is believable on its
face to persons skilled in the art in view of the
state of the art as of the filing date, then the burden
is upon the Examiner to give adequate support
for rejections for lack of utility. As stated by
Commissioner Lehman at a hearing on 17 October
1994: ‘In other words, if an applicant presents a
scientifically plausible use for the claimed inven-
tion, it will be sufficient to satisfy the utility
requirement’. Two types of inventions that tend
to fail the utility test are perpetual motion machines
(the Patent Office wants to see working models of
these) and ‘unbelievable’ cures without supporting
experimental data (e.g. a cure for AIDS).
Unobviousness. The third, and most difficult,
criterion isunobviousness, or inventive step, as it
is known outside the United States. The process for
deciding whether or not an invention is obvious
was succinctly stated in a US court decision (the
Deere case). According to the Deere decision, the
Patent Examiner should determine obviousness
using a three-prong approach:- Determine the scope and content of the prior art;
- Ascertain the differences between the prior art
and the claims; and - Resolve the level of ordinary skill in the perti-
nent art.
Although Deere is a US decision and is only bind-
ing therein, the principle enunciated is followed,
more or less, by most patent offices worldwide.48.5 CRITERIA FOR OBTAINING A PATENT 623