Patent Law’s Enablement Requirement and Genus Claims: What Will SCOTUS Have to Say in Amgen v. Sanofi?  

This blog discusses a patent law case which SCOTUS has decided hear on the enablement requirement as it applies to genus claims.  The anticipated decision will have ramifications in particular in the life sciences industry which includes the biotech and pharmaceutical industries.


Even if the invention described in a patent application meets the subject matter eligibility (35 U.S.C § 101), novelty (35 U.S.C. § 102), and non-obviousness requirements (35 U.S.C. § 103) for patentability, the applicant must still describe the invention with enough particularity such that those skilled in the art will be able to make, use, and understand the “parameters” of the invention disclosed and claimed.  Under 35 U.S.C. § 112, this requirement involves 2 major factors: 1) the enablement requirement; and 2) the written description requirement.   The statute states:

The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.

Granted patent claims can later be invalidated on the basis of non-enablement or an inadequate written prescription in an inter partes proceeding before the Patent Trial & Appeal Board or during patent infringement litigation.  In long-time patent infringement litigation involving the biopharmaceutical firms Amgen and Sanofi, the enablement requirement issue has become intertwined with civil procedure issues:  is the determination of whether the patent description meets the enable requirements a question of law (to be decided by the presiding judge(s)) or fact (to be determined by a jury)?  In 2021, the U.S. Court of Appeals for the Federal Circuit (CAFC) affirmed the District of Delaware’s invalidation of Amgen’s patent claims asserted against Sanofi as a matter of law in a post-verdict motion.  These very same invalidated claims had previously survived Sanofi’s “lack of enablement” allegations in two separate jury verdicts which the District Court ignored by ruling in favor of Sanofi. Amgen, Inc. v. Sanofi, 987 F.3d 1080 (Fed. Circ. 2021).

In Nov. 2021, Amgen filed a petition for writ of certiorari requesting the Supreme Court to grant the writ for the purpose of addressing two patent enablement questions raised by the CAFC’s opinion.  The first question pertained to whether enablement determinations are a question of law or fact.   The second question pertained to what level of experimentation is required to make Amgen’s invention enabled under 35 U.S.C. § 112(a) for its genus claims.  The Court invited the U.S. Solicitor General to file a brief; the resultant brief counseled against granting the writ.

Amgen filed a reply, arguing that the government’s own brief created a “disagreement with everyone” that further supports SCOTUS’s review. In support of the writ, Amgen emphasized that the Supreme Court’s “a question of fact” standard for enablement extends back to the pre-Civil war era in the 1847 case of Wood v. Underhill.  Amgen also argued that the Solicitor General’s brief failed to respond to arguments that the Seventh Amendment prohibits reexaminations of jury verdicts except under common law standards, which should have precluded the CAFC from reviewing the jury’s enablement finding de novo.   Finally, Amgen argued that the government never explained why a claim should be invalidated based on the cumulative effort to make all embodiments where, as with Amgen’s invention, such efforts would not require undue experimentation for those skilled in the art.  Indeed, the CAFC, in finding non-enablement, had opined that the the enablement standard for a genus claim may be raised if “substantial time and effort would be required to reach the full scope of the claimed embodiments.”

On Nov. 4, 2022, SCOTUS granted Amgen’s writ on Question 2 only: Whether enablement is governed by the statutory requirement [35 U.S.C. § 112(a)] that the specification teach those skilled in the art to “make and use” the claimed invention or whether it must instead enable those skilled in the art “to reach the full scope of claimed embodiments” without undue experimentation – i.e., to cumulative identify and make [the invention] or nearly all [of its] embodiments.”

The Public Policy Behind the Enablement Requirement 

Patent protection lasts for about 20 years from the application’s filing date.  Through the government’s grant of this limited monopoly, the patentee has the right to exclusively use and exploit the invention.  After a patent expires, anyone can use, or sell, or import the invention covered by the patent. As such, the enablement requirement is intended to ensure that the public can actually derive benefit after the granted monopoly period is finished by making and using the invention.  Accordingly, the patent disclosure must provide sufficient information for allowing such persons to make the invention after the patent has expired.

Another aspect of the enablement requirement is to prevent the introduction of new matter during prosecution of the patent application.   MPEP 2164.05(a). Accordingly, the patent application is not to be “adjusted” to include new matter during prosecution.  This requirement is intended to help ensure that the patent application is thorough and complete at the time of filing.

What Does It Mean for an Invention to Enabled?

An enabled invention is one which is sufficiently instructive such that who is skilled in the art could make and use the invention without undue experimentation.  This requirement is not as straight forward as it may seem because all inventions are not equal with respect to their complexity or subject matter.   Storer v. Clark, 860 F.3d, 1340, 1350 (Fed. Circ. 2017).   New and more complex inventions may require more description and “directions” to meet the enablement requirement.   Also, for all claims to be approved under the enable requirement, the disclosure must sufficiently enable all of the claims.  In re Borkowski, 422 F.2d 904, 909 (CCPA 1970).

On the other hand, the enablement requirements does not require that the patent disclosure explain how to make a perfected, commercially viable embodiment of the invention.  See Christianson v. Colt Indus. Operating Corp., 822 F.2d 1544, 1562 (Fed. Cir. 1987).  Also, any invention may be associated with know-how and trade secrets (e.g., a raw material with desirable purity specifications to improve invented-product yields) which need not be revealed providing the trade secrets are not critical to the patentability of the invention.

The relevant factors courts have used in determining if the enablement requirement is met may “include (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; (6) the unpredictability of the art; and (8) the breadth of the claims.”   In re Wands, 858 F.2d 731, 738 (Fed. Cir. 1988) (reversing the USPTO’s refusal to approve the patent applicant’s claims on non-enablement grounds and stating “[c]onsidering all of the factors, we conclude that it would not require undue experimentation to obtain antibodies needed to practice the claimed invention.”).  The commentator notes that this decision was at a time when biotechnology patents were in favor thanks to SCOTUS’s 1980 decision in Diamond v. Chakrabarty, 447 U.S. 303 (1980).  That decision is credited with paving the way for the rapid growth of the then-new biotechnology industry.  And now 40 years later SCOTUS is widely viewed as stifling innovation in today’s related technologies.

The subject patents the CAFC invalidated in Amgen v. Sanofi are directed to a genus of antibodies defined not by their structure (e.g., their amino acid sequence) but by their function, i.e., the ability of the monoclonal antibodies to bind a certain part of the PCSK9 antigen.  PCSK9 is a target for treating levels of LDL (the particularly “dangerous” form of cholesterol).   Accordingly, monoclonal antibodies directed against PCSK9 may still work with various sequence changes.   Patentees in the life sciences have had a difficult time defending claims directed to discovery of a novel biological therapeutic which often involve a functional genus claim.  Narrowly drawn claims to only the patent’s disclosed variations of the invention do not always “appreciate” the full scope of the invention, giving potential infringers wiggle room.

Amgen’s petition for writ emphasized that the CAFC wrongly applied a “special test” for its genus claims after gutting the juries’ findings.  “This approach will have devastating ramifications for biotech and pharmaceutical innovations because “significant breakthroughs [in these industries] often involve the mechanism for producing a desired effect and making a working embodiment . . . [where] the mechanism . . .may have the same effect when implemented in any number of structurally similar compounds.”  Amgen Pet. at 3, 29-30.  Hence a functional genus claim is one where structurally similar biochemical structures may be able to achieve at least some of level of the claimed function or mechanism.  The CAFC’s opinion indicated that the enablement standard for a genus claim could be raised if “substantial time and effort would be required to reach the full scope of the claimed embodiments.”

In its reply to the Solicitor General’s brief, Amgen argued that the Solicitor General had also wrongly extended the scope of Section 112’s enablement requirement to require a skilled artisan to “reach the full scope of claimed embodiments” without “substantial time and effort.”  Amgen’s position is that  “[o]nce inventors teach skilled artisans how to make and use the individual embodiments across the scope of the claim, there is no reason why they should lose their patent because it would take a lot of work to make them all [consecutively].”  Amgen countered that this standard does not comport with the statutory language of Section 112 which has no language connecting enablement with the amount of time and effort required to practice all embodiments of the claimed invention.  Nor did the government explain “why a claim should be invalidated based on the cumulative effort to make all claimed embodiments where as here, it would not require undue experimentation to make and use any individual embodiment.”  Substantial time and effort is not necessarily undue experimentation.


Put another way, the question SCOTUS will be addressing in 2023 is the following:  under the enablement requirement, must an invention like Amgen’s disclose every single potential embodiment of the claimed functional invention and how to make it to meet the enablement requirement and thereby minimize time required for making the embodiments by future users who are skilled in the art?  The commentator adds that the question is related to the actual disclosure’s quality.  Is there sufficient disclosure to meet the enablement requirement for the disclosed embodiments which will allow future users having the requisite skill in the art to proceed in making the disclosed and additional embodiments of a genus claim even if considerable time is involved? Under the enablement requirement, future users should not have to reinvent the wheel to make the patented invention and its various embodiments.  But time and effort are not necessarily undue experimentation.  Even the seminal Wands case’s “enablement” factors do not refer to time and effort but the quantity of experimentation.   Experimentation is itself subjective – and could range from optimization experiments (e.g., to maximize the yield of a claimed process’s product) to experimentation directed to filling in a critical missing or vague step not disclosed in the original application.

In sum, the issue in Amgen v. Sanofi is whether a precise roadmap for making all embodiments of a genus claim must be disclosed to meet the enablement requirement.  Does “time and effort” refer to the “time and effort” for making a limited number of the patent’s discussed embodiments or the “time and effort” for cumulatively making all possible embodiments which of course will result require more time and effort.   Amgen Pet. at 2 (quoting Amgen, 987, F.3d at 1088).  The commentator notes that the methodology for making and growing monoclonal antibodies was first developed last century and is routinely used by biotech companies who rely on the quicker technologies which have been developed over the years to support the biotech and pharmaceutical industries.

In Jan. 2021, SCOTUS denied a cert petition filed by Idenix Pharmaceuticals for nearly identical issues of enablement of functionally defined genus claims after it lost its appeal.  Idenix Pharmaceuticals, LLC v. Gilead Sciences, Inc., 941 F.3d 1149 (Fed. Cir. 2019).  The Amgen case will be closely watched by the patent bar and the life sciences industries now that SCOTUS is finally involved. After many decisions which have invalidated patent claims and negatively impacted patent portfolios in the life sciences industry, there is optimism that patent owners will see a shift in the pendulum in favor of genus claims which are common in this industry given the nature of the beast.  Of interest is the fact that three amicus briefs have been filed in favor in Amgen, including one by highly respected Professor Mark Lemley of Stanford Law School on behalf of a group of intellectual property professors.  This commentator is rooting for Amgen.

Stay tuned for a blog on SCOTUS’s opinion.


© 2022 by Troy & Schwartz, LLC


Posted in Intellectual Property Law, Patent Law - Current Issues on November 15,2022 12:11 PM
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