Sufficiency of disclosure

Enablement

A patent disclosure "enables" the invention, if it allows a person of ordinary skill in the art to practice the invention without undue experimentation. Patents may fail this test if they claim more than they teach: for example, a patent that claims all light bulbs but explains only how to make a particular type of light bulb. A patent may also be non-enabling, if it claims the use of tungsten filaments in a lightbulb, but it does not disclose how to make tungsten filaments, and there is no publicly known method of making them.

A patent claim that does not meet the enablement requirement may be rejected by the patent examiner before patent issuance or declared invalid upon re-examination or litigation after issuance. Enablement is determined as of the filing date of the patent, and patent owners cannot use experiments conducted post-application to establish the validity of their patents.^[6]

Undue experimentation

Under the patent law in the United States, the enablement requirement is not satisfied, if a person having "ordinary skill in the art" (PHOSITA) of the invention cannot make and use the invention without undue experimentation.^[4]

Undue experimentation is not based on quantity of experimentation as much as it is on unpredictability of outcome.^[7] In the "predictable arts", such as mechanical inventions and software inventions, very little description is required. A mere flow chart of a piece of software, for example, is adequate. Source code is not normally required. In the “unpredictable arts”, such as chemistry and pharmaceuticals, a very detailed description is required.^[8]

In 1988 Federal Circuit established 8 Wands factors that can be considered when determining whether a disclosure requires undue experimentation:^[9]

1. the quantity of experimentation necessary;
2. the amount of direction or guidance presented;
3. the presence or absence of working examples;
4. the nature of the invention;
5. the state of the prior art;
6. the relative skill of those in the art;
7. the predictability or unpredictability of the art; and
8. the breadth of the claims.

In a 2005 U.S. court case, several of Jerome H. Lemelson patents covering bar code readers were held to be invalid because the specification was not complete enough for a person of ordinary skill in the art of electrical engineering to have made and used the claimed invention at the time the patent was filed (1954) without undue experimentation. In this case the court held that a person of ordinary skill in the art was a degreed electrical engineer with two years of experience as of the filing date of the original patent application, 1954. One of the challenges of this court case, which was decided in 2005, was to find experts on the state of the art who were alive in 1954.^{[citation needed]}

In May 2023, the U.S. Supreme Court did not specifically address the eight Wands factors in its decision in Amgen Inc v. Sanofi. However, the Court stated that the specification may call for a reasonable amount of experimentation to make and use the full scope of the claimed invention.^[10]

Written description and possession

In the United States, the would-be patentee must provide a "written description" of the invention, sufficient to support the claims of the patent during the patent's examination. "Written description" determines the scope of claims.^[11]

The purpose of this rule is to avoid applicants speculatively filing for patents for inventions that they have not yet invented in order to get priority over competitors. As the Federal Circuit explained in Amgen Inc. v. Hoechst Marion Roussel, Inc. 314 F.3d 1313, 1330 (Fed. Cir. 2003), "[t]he purpose of the written description requirement is to prevent an applicant from later asserting that he invented that which he did not."

An illustrative landmark decision on the issue of "written description" was University of Rochester v. Searle,^[12] related to patents on COX-2 inhibitors. In the early 1990s scientists at the University of Rochester discovered two disctinct cyclooxygenases, referred to as COX-1 and COX-2. For most patents it is desirable to inhibit COX-2 and not COX-1. Previously known NSAIDs inhibit both COX-1 and COX-2, and thus they not only reduce inflammation, but also cause side effects such as stomach upset, irritation, ulcers, and bleeding. This breakthrough discovery prompted the Rochester scientists to launch a program for developing selective COX-2 inhibitors, and they developed an assay to screen for such inhibitors, which was a subject of patent US5837479 issued in 1998, that claimed methods "for identifying a compound that inhibits prostaglandin synthesis catalyzed by mammalian prostaglandin H synthase-2 (PGHS-2)." While disclosing the discovery of the target enzyme (which is an unpatenable product of Nature) and the methods for identifying its inhibitors, the US5837479 did not provide any specific formulas for the claimed inhibitors. "Accordingly, the court concluded that the patent's claims are invalid for lack of written description," because "it claims a method of achieving a biological effect, but discloses no compounds that can accomplish that result."^[13]

To summarize: without the written description/sufficiency of disclosure requirement, an applicant might delay scientific and technical progress by blocking competitors from inventing something that the applicant has not yet invented (i.e. did not describe in his patent application). The written description requirement thus reinforces the idea that patents are a reward for inventing by requiring the applicant to show they possess the invention.^[14]

Deposit of biological material

The examples and perspective in this section deal primarily with the United States and do not represent a worldwide view of the subject. (June 2023)

Biological (i.e. "capable of self-replication either directly or indirectly")^[15] materials (such as yeast, algae, protozoa, eukaryotic cells, cell lines, hybridomas, plasmids, viruses, plant tissue cells, lichens, seeds, vectors, cell organelles etc.) can be patented in the US as compositions of matter or as articles of manufacture, provided that they are useful, novel and non-obvious. However, a precise description (such as molecular structure) is not always possible in such cases, which makes it difficult to meet written description and enablement requirements for claims involving biological materials. One option to claim such biological inventions is by using plant patents. Another option is to use regular utility patents in combination with a deposit of the claimed biological material according to Budapest Treaty of 1977. The US law allows for such biological deposit(s) to be made at any time before the patent issuance (and in some cases during reexamination), however many other countries require deposits before patent filing.^[15] Such deposits are typically made for 30 years.

Best mode

In the United States, the sufficiency of disclosure requirement is complemented by an additional requirement, generally not found in other national patent jurisdictions: the "best mode requirement". According to the requirement, the disclosure must also contain the inventor's "best mode" of making or practising the invention. For example, if an inventor knows that a liquid should be heated to 250 degrees for optimal performance, but discloses in the patent that the liquid should be heated to "above 200 degrees", then the inventor has not disclosed his "best mode" for carrying out the invention. The best mode must be disclosed for the entire invention, and not only its innovative aspects.^[16]

The purpose of the “best mode” requirement is to ensure full disclosure, such that the inventor may not “disclose only what he knows to be his second-best embodiment, retaining the best for himself.”^[17]

The "best mode requirement" only applies to what the inventor knows at the time the application is filed, not to what is subsequently discovered.^[18]

Post-AIA, US law no longer permits invalidation of a US patent for failure to disclose the best mode, although technically the best mode is still required to be disclosed by the language of 35 U.S.C. Section 112.