Under the U.S. Patent Act, a patent may be obtained for “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.” The requirement that the subject of a patent be new is referred to as the novelty requirement; the requirement that the subject of a patent be useful is referred to as the utility requirement.
To meet the utility requirement, an invention must provide a specific, known use that differs from the prior art, which is the body of information from which it is determined whether an invention is new. Speculative or possible future utility is not sufficient. Application requirements set out by the Patent Act provide that the patent applicant describe in detail the invention, how to make it, what it does, and how it is used, which if properly complied with should make it clear what the claimed utility of the invention is. It is not necessary that the use represent an improvement over the prior art; however, to meet the utility requirement, an invention must work as claimed.
The utility requirement is liberally applied to pharmaceutical compounds. In a leading case on the utility requirement, the U.S. Court of Appeals for the Federal Circuit reversed a decision of the United States Patent and Trademark Office that a pharmaceutical compound was not patentable because, although the compound had anti-tumor properties, the patent application did not specify any specific disease for which the compound might be used to treat. The court held that a compound that exhibits a desirable pharmaceutical property in animal testing has made a significant and useful contribution to the art and, thus ,meets the utility requirement. In addition, the court concluded that is to be expected that further research and development in a pharmaceutical compound will be necessary to fully determine the specific medical uses for the compound.
In examining a patent application for utility, a patent examiner determines whether there is a well-established utility for the invention or a utility that is asserted by the applicant that is credible. The credibility of an assertion of utility is measured by the standard of a person having ordinary skill in the field in which the invention is classified. If there is either a well-established or credible use asserted by the applicant, the patent application will not be rejected on the ground of lack of utility.