Tag Archives: functional claims

Functional Claims: Morse, Halliburton & Amgen

by Dennis Crouch

In the patent context, functional limitations describe inventions in terms of their function or intended use, rather than their specific structure or components. Such claims have been subject to much debate and litigation throughout the history of the US patent system. Notable Supreme Court cases like O’Reilly v. Morse, 56 U.S. (15 How.) 62 (1854) and Halliburton Oil Well Cementing Co. v. Walker, 329 U.S. 1 (1946) significantly impacted patent practice and the balance between functional and structural claim drafting.

The pending Supreme Court case of Amgen Inc. v. Sanofi, No. 21-757 (2023) is another example, with the potential to further shift the landscape regarding functional claim limitations. The title of my essay on the case following oral arguments, “Bye Bye Functional Claims,” hints at my outlook. Although the patentee focused on other issues in its briefing, the Justices repeatedly questioned the permissibility of broad functional claim limitations.

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Bye Bye Functional Claims

by Dennis Crouch

Oral arguments from Amgen v. Sanofi suggest the potential of a blockbuster Supreme Court decision further derogating functional claim limitations (all of which are also genus claims).  A key question is whether the court will include limiting language that that directs impact primarily upon the “unpredictable arts.”

At oral arguments, the Supreme Court was quite hostile to the patentee counsel Jeffrey Lamken and his attempt to defend Amgen’s functionally claimed genus of antibodies.  I believe that Lamken took the wrong turn by first repeatedly telling the court that the claim covered only about 400 antibodies, before eventually admitting that a scope covering millions of yet unidentified antibodies.  I could taste the bitterness in the further questions.  Several members of the court struggled with the expressly functional claim limitation that permitted Amgen to claim all antibodies that achieve its stated results.  Lamken suggested that the “PTO regularly issues patents which have that sort of functional piece.”  Of course, the PTO also regularly issues invalid and overbroad patents.  In questioning, the court clearly thought we had a potential eligibility problem because of the functional limit. In his response Paul Clement picked-up on that issue and explained that the functional genus claim is “a work-around of Myriad. Because basically they’re pointing to something that exists in nature [the PCSK9 pathway] and they’re saying, we claim everything that works to bind there en bloc.”

In Amgen v. Sanofi, the Supreme Court  agreed to reevaluate the doctrine of enablement as applied by the Federal Circuit.  Although juries twice sided with the patentee, the district court and the court of appeals both rejected the jury verdict and concluded that lacked an enabling disclosure as a matter of law.  The Federal Circuit particularly noted (1) that functional limitations are much more difficult to enable than are structural limitations and (2) that each embodiment covered by a genus claim must be enabled.  Here, the court noted that Amgen had failed to enable the “far corners of the claimed landscape.”

Amgen has requested the court to incorporate a meaningful limitation into the enablement test.  In that framework, a patent challenger would need to show both (1) that some embodiments requires undue experimentation in order to recreate and (2) that those failures would be meaningful to skilled artisans.  And, Amgen suggests that functional genus should not face heightened scrutiny.  Lastly, Amgen suggested that the Wands Factors should be given less weight – that today they are being used as the test, rather than for functional support.  The particular Wands problem for the patentee here is the notion that antibodies are “unpredictable” and therefore require more disclosure.

The case is a very big deal, and not just for antibodies.  Every claim covers myriad undisclosed embodiments; Everyone is using lots of functional limitations; and Every patent suffers from unenabled far corners.

The claim here:

1. An isolated monoclonal antibody, wherein, when bound to PCSK9, the monoclonal antibody binds to at least one of the following residues: S153 … or S381 of SEQ ID NO:3, and wherein the monoclonal antibody blocks binding of PCSK9 to LDLR.

The Amgen invention centers around a pathway that others discovered regarding LDL, AKA “bad cholesterol,” the liver’s role in destroying bad cholesterol, and a new protein PCSK9.  The liver has LDL receptors (LDLRs) that bind and break-down LDL.  But, the body also makes a protein known as PCSK9 that competitively binds to those receptors and blocks the liver LDL-breakdown action.  In creating its invention, Amgen set out to find monoclonal antibodies that bind to PCSK9 and block its operation — and thus allow the liver to do its LDL-breakdown work.  The process for doing this was somewhat straightforward. They first injected a humanized-mouse with PCSK9 in order to cause an immune reaction to attack the foreign body.  The mouse created a bunch of antibodies (about 3,000) that bind to PCSK9.  These were then all tested (using standard rapid testing tools) to determine which ones bind the “sweet spot” of PCSK9 — and thus would have the impact of “block[ing] binding of PCSK9 to LDLR.”  This process brought it down to about 400 antibodies.  However, Amgen did not actually take the time to figure out the amino-acid sequence for of each of these. Rather, it did so for 16 of them and called it good.  Sanofi’s product is – most likely – one of the 400 discovered by Amgen, but was not literally described in the Amgen patent. Rather, Amgen described the process, and also described the use of a codon-replacement process to check similar antibodies (that is where the millions come-into play).

A key quote from Clement was be the following: “I think functional genus
claims are terrible.”  The essence of his argument is that they have the potential of giving the patentee a broad scope covering numerous radically different solutions.  The result though is that nobody has incentives to look for the others because of the covering patent.  “They retard the science.”  In his view, a more limited monopoly is much better — “We’re better off with two competing independently developed therapies.”

Colleen Sinzdak argued on behalf of the US Gov’t as amicus and in support of Sanofi.  Sinzdak was in complete agreement with Clement, arguing that broad genus claims are “a danger to innovation and especially in the medical field.”

The Government argued that a genus claim is only proper if each and every embodiment within the genus has been enabled. “It really is that simple. … you really do need to enable each of the different embodiments that you’re claiming.”  Sinzdak argued that in an unpredictable, fast-moving field, the law should be more stringent in order to allow an early patent to unduly grab land and shut-down further research.   Sinzdak suggested that the court force narrow claims and then let folks rely upon the doctrine of equivalents if necessary.

Lamkin’s important rebuttal point: Although Amgen did not literally disclose every embodiment, and some covered embodiments are quite structurally different from those disclosed, “the key fact in this case is that Sanofi has not identified one antibody that would require undue experimentation to make.”