United States Supreme Court Reviews The Enablement Requirement For The Second Time in History
Most patent litigation cases do not hinge on questions of whether the patents-in-suit meet the enablement requirement. As a result, these issues do not often reach the Supreme Court of the United States. That has now changed. For the second time in history, the Supreme Court of the United States has agreed to review a case to address the enablement question.
The enablement requirement is found in 35 U.S.C. § 112(a) and requires the inventor to describe the invention in such a way that would allow others skilled in the art to make and use the invention. The inquiry into whether enablement is sufficient is an objective one of whether those of ordinary skill in the art would be able to practice the invention without undue experimentation.
Determining whether “undue experimentation” is needed involves various factual considerations, known as the Wands factors. These factors include the quantity of experimentation necessary, the amount of direction or guidance presented, the presence or absence of working examples, the nature of the invention, the state of the prior art, the relative skill of those in the art, the predictability or unpredictability of the art, and the breadth of the claims.
Courts may consider these factors after a patent challenger has presented evidence that some experimentation is needed to practice the patented claim. Considering these factors, the court can determine whether the amount of experimentation is either undue, which suggests invalidity, or sufficiently routine that a person of ordinary skill in the art would reasonably be expected to carry it out. A specification is not required to describe how to make and use every possible variant of the claimed invention; however, it must reasonably enable the full scope of a claimed range if a range is claimed.
Amgen v. Sanofi – Background
Amgen v. Sanofi involves Amgen’s patents on REPATHA, a cholesterol medication. The case has a lengthy and complex procedural history since Amgen first sued Sanofi in 2014, involving two trials and two appeals to the United States Court of Appeals for the Federal Circuit (“the Federal Circuit”) before being postured for potential Supreme Court review. Although juries twice concluded that the patents were not invalid due to lack of enablement, after a second trial, the district court granted Sanofi’s motion for judgment as a matter of law, concluding the patents were not enabled and, therefore invalid as a matter of law.
In the second appeal, the Federal Circuit agreed with the district court’s conclusion of invalidity. The appellate court concluded that when claims include functional requirements, the enablement inquiry can be focused on the breadth of those functional requirements, particularly where predictability in the results and guidance from the specification are lacking. The court emphasized the importance of considering the quantity of experimentation that would be required to make and use the full scope of the claim, and not just the limited number of embodiments disclosed in the patent. The court explained that when claims involve not only certain structural requirements but also the performance of certain functions, then the “undue experimentation” inquiry can include consideration of the level and type of effort required to identify the compounds that satisfy the functional requirements from the many concretely identified compounds that meet the structural requirements.
Ultimately, the Federal Circuit found that the claims in Amgen’s patent fell into the category of cases in which broad composition claims require disclosure of not only particular structure, but particular functionality as well, resulting in too many possible claimed compounds to ascertain without undue experimentation. The court was persuaded that the only ways for those skilled in the art to discover undisclosed claimed embodiments would be either through a significant trial and error process, or by discovering antibodies by using the patent’s disclosed randomization and screening roadmap, which the court concluded would result in experimentation that “would take a substantial amount of time and effort.” Because of the breadth of the functional limitations, and the narrowness of the disclosed examples and guidance, the Federal Circuit concluded no reasonable jury could conclude that anything but “substantial time and effort” would be required to determine the full scope of the claimed invention.
Amgen’s Petition to the United States Supreme Court
Following the Federal Circuit’s affirmance of the invalidity decision, Amgen petitioned the Supreme Court for further review of two issues. First, did the district court err in making its findings of lack of enablement instead of leaving the question of enablement to the jury (which, in this case twice found the patents were properly enabled)? According to Amgen, the Federal Circuit erred in holding that enablement is an issue for judges to decide, as opposed to juries, in view of a nearly 180 year old Supreme Court decision holding that enablement is a question of fact to be determined by the jury. Second, Amgen asked whether the Federal Circuit wrongly held that the enablement requirement requires a person of ordinary skill in the art to “reach the full scope” of the claimed invention.
Sanofi was invited to respond to Amgen’s petition and argued that patent validity has long been a question of law with underlying factual underpinnings, and courts have always retained the right to make rulings on even purely factual issues when there is an insufficient evidentiary showing. Sanofi also argued that it is clear that a patentee has not sufficiently enabled an invention if the patent describes how to make and use only part of the claimed invention.
What could change now that the Supreme Court has granted review?
On November 4, 2022, the Supreme Court accepted Amgen’s petition and granted certiorari. The Supreme Court does not explain why it accepts cases for review, however, and there are a number of possible explanations in this case.
First, although the “full scope of the claim” enablement standard as applied to functional claims is not entirely new in Federal Circuit jurisprudence, the Amgen decision appears to conflict with prior Federal Circuit precedent holding that claim coverage of some inoperative embodiments would not necessarily invalidate a claim for lack of enablement. Second, the Amgen might be read as shifting the burden of proving enablement, i.e., patent validity, to the patentee by requiring proof that the full breadth of the claims is enabled without the challenger needing to identify a particular embodiment that was not enabled.
If the Federal Circuit’s Amgen decision is affirmed, implications could be far-reaching in that broad functional genus claims could become particularly vulnerable to enablement challenges. As Amgen warns in its petition, only time would tell how “devastating” the effect could be on innovation.
As a practical matter, patent practitioners in the meantime should pay particular attention to the Wands factors when drafting pharmaceutical patents, and should provide as much direction as possible, and should carefully select and describe embodiments in the specification. It would also be wise to include subgenus and species claims, just in case broader genus claims are invalidated. Meanwhile, litigators can expect enablement challenges for broad functional genus claims, increasing the need to develop strategies and gather necessary evidence early in the discovery phase to address issues that will arise in such challenges.
However the Supreme Court views these issues, its decision sometime in 2023 will be headline news in patent law. We will report again when further developments warrant.
 Prior to the enactment of the America Invents Act, which made certain amendments to this and other statutes, 35 U.S.C. §112(a) was known as §112 ¶ 1.