Enablement

The statute does not use the words "undue experimentation", but the MPEP says it has been interpreted to require that the claimed invention be enabled so that any person skilled in the art can make and use it without undue experimentation². Several rules follow from the MPEP's treatment:

• The test is not whether any experimentation is necessary, but whether, if experimentation is necessary, it is undue².
• The specification does not have to enable a perfected, commercially viable embodiment, unless a claim limitation requires one².
• A patent need not teach, and preferably omits, what is well known in the art².
• Enablement is a question of law based on underlying factual findings².

Enablement is separate and distinct from the written description requirement, so a new claim limitation can lack descriptive support without necessarily lacking enablement².

The Federal Circuit set out a framework of factors in In re Wands (Fed. Cir. 1988) for judging whether the experimentation a specification requires is reasonable or undue. The MPEP lists them as follows, and says they are not limited to these²:

• The breadth of the claims².
• The nature of the invention².
• The state of the prior art².
• The level of one of ordinary skill².
• The level of predictability in the art².
• The amount of direction provided by the inventor².
• The existence of working examples².
• The quantity of experimentation needed to make or use the invention, based on the content of the disclosure².

It is improper to conclude that a disclosure is not enabling by analyzing only one factor while ignoring the others: the examiner must weigh all the evidence, and a conclusion of nonenablement must rest on the evidence as a whole². The MPEP describes Wands as a case in which the court found the specification enabling for claims to detecting hepatitis B surface antigens, noting considerable direction and guidance in the specification, a high level of skill in the art and well known methods².

In Amgen v. Sanofi (2023) the Supreme Court held that if a patent claims an entire class of processes, machines, manufactures or compositions of matter, the specification must enable a person skilled in the art to make and use the entire class. In its words, the specification must enable the full scope of the invention as defined by its claims, and the more one claims, the more one must enable³.

The Court added that this does not always require describing how to make and use every embodiment. It may suffice to give an example or a few examples if the specification also discloses some general quality running through the class that gives it a peculiar fitness for the particular purpose³.

The MPEP says the Wands factors continue to provide a framework for assessing enablement in a utility application or patent, regardless of technology area². It also quotes the Federal Circuit as seeing no meaningful difference between Wands' undue experimentation and Amgen's unreasonable experimentation standards².

Both come from 35 U.S.C. 112(a) and both are tested against the claims, but the US treats them as two requirements^2,7.

The US Supreme Court applied the enablement requirement to claims covering a whole class of antibodies defined by their function³.

Amgen identified the amino acid sequences of 26 antibodies and described two methods for making others, but claimed the entire genus of antibodies that bind specified residues on PCSK9 and block it from binding LDL receptors. The Court held that the courts below correctly concluded the claims were not enabled, and affirmed3.