On January 19, 2021, the Supreme Court denied a petition for certiorari to hear the Idenix Pharmaceuticals LLC v. Gilead Sciences Inc. case (941 F.3d 1149 (Fed. Cir. 2019)). In the underlying district court litigation, the jury found the Idenix patents were infringed, awarding it $2.5 billion in damages. But, the district court overturned the verdict and granted judgement as a matter of law finding the patents invalid for lack of enablement, and the Federal Circuit affirmed. To revive its damages claim, Idenix filed a petition to reverse the Federal Circuit’s decision. The petition addressed whether a genus claim is not enabled if it encompasses a large number of compounds or whether, as the Supreme Court has previously recognized, enablement is a context-specific jury question (as well as a related written description issue that will not be discussed further).

In Idenix, the Federal Circuit held that the patents in suit were invalid for lack of enablement because of the undue experimentation needed to synthesize and screen compounds in order to meet the disclosed functional limitations. As applied to the biotechnology context, the scope of enablement varies “inversely with the degree of unpredictability of the factors involved.” (941 F.3d at 1161.) The patents in Idenix involved using modified nucleoside compounds for medical treatment, and the Federal Circuit noted that using such compounds is a highly unpredictable art, where “the smallest change can have a dramatic effect not only on the activity of that compound but on the toxicity of the compound.” (Id.) In addition, the court recognized that there were billions of potential nucleosides but only a small group of candidate compounds that would effectively treat the target disease. (Id. at 1156.) The disparity between the number of potential compounds compared to the number of potential effective compounds led the Federal Circuit to determine there was a need for significant experimentation, as practicing the full scope of the claims would require excessive experimentation regardless of whether such experimentation would be considered routine.

Critics of the Federal Circuit’s decision, including Judge Newman, who wrote the dissent in Idenix, and the amicus briefs filed in support of the petition for cert, have taken the position that the enablement rule created by Idenix is too limiting and will be impossible to comply with, particularly in more unpredictable arts like biotechnology. The stringent enablement requirement essentially holds that even routine experimentation can be considered undue experimentation. As a result, the standard effectively eliminates the patentee’s ability to claim a genus of a compound because the patent must teach a person skilled in the art to distinguish operative embodiments from even the rarest inoperative embodiments. Critics maintain that such a strict standard goes against the Patent Act itself, since the Act does not require the patentee to enable artisans to make and use every embodiment of an invention. As a practical matter, there is concern that such an unworkable standard will destroy the incentive to develop novel chemical structures, as genus claims are vital to continued innovation specifically in the chemical and pharmaceutical industries.

However, those in support of the Idenix enablement standard have argued that the standard merely prevents patentees from abusing genus claims by trying to monopolize more than they invented. Accordingly, the Idenix standard poses no threat to sound genus claims, but rather the rule simply evaluates whether the patent’s disclosure is commensurate with the scope of the claims. Further, supporters point out that Idenix did not result in any fundamental change in patent doctrine, and note that there is no real risk posed to pharmaceutical innovators, as it essentially maintains the status quo. To overrule Idenix, they argue, would allow overbroad genus claims that would threaten discovery and innovation. In their view, the current enablement standard promotes, rather than hinders, innovation in the biotechnology industries.

In light of the Supreme Court declining the petition for certiorari, the enablement standard articulated in Idenix remains the rule. Accordingly, the dispute over whether the enablement standard is too burdensome in biotechnology patent cases continues, and it remains to be seen whether the standard will be modified in the future in order to address concerns of stifling the development of novel compounds.

In the meantime, patent applicants should draft their specifications with this holding in mind: genus claims need to be supported as much as possible by concrete data in the specification, ideally limiting the amount of (even routine) experimentation necessary. This poses particular challenges for universities and smaller biotech companies who tend to file early. Conversely, patent challengers should be cognizant that enablement challenges to patents granted prior to Idenix may be subject to challenge under the Idenix rationale, and this could be a powerful tool in a potential defendant’s arsenal.

Illustrating this point, the strict enablement standard continues to have significant repercussions, as seen in the Amgen Inc. v. Sanofi case decided yesterday, February 11, 2021, where the Federal Circuit affirmed a Delaware federal judge’s finding that the claims of two Amgen patents were too broad to satisfy the enablement requirement. A Court held that it would have required undue experimentation to determine the bounds of the claims of Amgen’s patents, directed to its cholesterol medication Repatha. The Federal Circuit noted that the functional limitations were broad and the disclosed examples and guidance were minimal. As a result, substantial time and effort would be required to reach the full scope of claimed embodiments, with insufficient guidance given to a person skilled in the art to enable the full scope of the claims. Amgen, in response to the ruling, expressed concern: “patent protection is essential not only for Amgen but also for the entire biotechnology and pharmaceutical industry to make the significant investments required to discover and develop new innovative therapeutics that serve unmet patient needs.”