Orange Book Blog

Last week the Federal Circuit decided Teva v. Lilly, restoring the jury’s verdict that Teva’s claims to methods of using CRGP antagonists to treat headache were not proven invalid under 112.

The facts are at a high level, relatively straightforward. Teva’s patent family claimed CGRP antagonists as well as methods of using such antagonists to treat headaches. Lilly challenged those patents through IPRs, with the Board finding the product claims unpatentable based on Lilly’s arguments that the genus of antagonists was well-known and routine to achieve, but upholding the method of use patents finding no reasonable expectation of success in using the genus to treat headaches. The Federal Circuit affirmed both decisions. The parties went to trial, and Lilly argued that the method of use claims were invalid under 112 because they claimed the use of every possible humanized anti-CGRP antibody with no limitation on structure, while disclosing only a single working example within the scope of the claims. The jury found in favor of Teva, but the district court granted Lilly’s JMOL, concluding that the single representative species was not enough under the circumstances of claiming a broad genus. The Federal Circuit reversed, finding substantial evidence could support the jury verdict.

The most controversial aspect of the opinion is that it can be read as drawing a bright-line distinction between claims to a product and claims to method of using the product for the purposes of 112 and applying Amgen. Indeed, the court wrote “Lilly takes issue with the distinction we have drawn between (1) claims to a method of using humanized anti-CGRP antagonist antibodies to treat headache and (2) claims to such antibodies themselves” rejecting Lilly’s argument that this is a “semantic distinction without a difference.” And the court later stated “we note that Lilly’s argument might be more persuasive if the asserted claims were to the genus of humanized anti-CGRP antagonist antibodies themselves. If that were so, this case would resemble Amgen….The asserted claims here are unlike the claims in Amgen[], however, because they do not claim humanized anti-CGRP antagonist antibodies themselves; instead, they claim only the use of such antibodies for the different, limited purpose of treating headache.”

I certainly can’t disagree with anyone who reads this as the holding, and criticizes that holding as nonsensical and emphasizing semantic differences in claiming with unfair results. And I’ll certainly agree the Federal Circuit could have better addressed Lilly’s argument and explained why it was not creating a semantic difference. But I think given the opinion as a whole, that is now how the holding should be read. For example, when distinguishing the cases Lilly cited regarding semantic differences, the court said that neither addressed “a well-known genus used as part of a different invention.” Similarly, when distinguishing Amgen, the court emphasized “In light of the well-known status of anti-CGRP antagonist antibodies and the routine nature of humanization, the more relevant ‘research assignment’ in this case would have been determining which humanized anti-CGRP antagonist antibodies treat headache. [] That assignment was completed; the specification disclosed that all such antibodies work for that purpose.”

In other words, while this point should have been made more clear, I read the holding as turning on the factual determination of the number of representative species and whether there was sufficient support for the genus, not whether it was a method claim. When the court emphasized that the invention was the method of treating headaches, not merely the antibodies themselves, I believe they were inartfully trying to explain why the claims could be novel and non-obvious while relying on the prior art to provide written description and enablement support. But the 112 holding itself was based on finding a sufficient disclosure and enablement of the full genus of antibodies and the belief that the district court too narrowly analyzed the disclosure of the specification in light of the prior art.

Specifically, when analyzing the number of representative species, the district court recognized that “the jury could have found that (1) a POSA would have known methods for making murine (mouse) anti-CGRP antibodies, (2) a POSA could generate anti-CGRP antagonist antibodies, (3) a mouse immunized with CGRP would generate anti-CGRP antibodies, (4) antibodies that antagonize CGRP could be identified using tests that could analyze millions of potentially relevant antibodies in days, and (5) a POSA could confirm an antibody’s ability to antagonize CGRP in animals.” Teva Pharms. Int’l GmbH v. Eli Lilly & Co., No. 18-CV-12029-ADB, 2023 WL 6282898 (D. Mass. Sept. 26, 2023). However, the district court concluded that a “reasonable jury could not have found that the Patents-in-Suit disclosed more than one humanized anti-CGRP antagonist antibody within the scope of the Asserted Claims” and noted that the “jury heard uncontroverted evidence that no humanized anti-CGRP antagonist antibodies were known in the prior art.” Id. at *11.

The Federal Circuit focused on different evidence stating a “reasonable jury could have found that anti-CGRP antagonist antibodies themselves and methods of making them were well known, replete, or extensively described in the prior art—based on Lilly’s own statements that they were ‘well known,’ ‘replete,’ or ‘extensively described’ in the prior art. A reasonable jury could have also found that humanization was a well-established and routine procedure by the priority date—again, based on Lilly’s own statements that it ‘was a well-established and routine procedure’ by the priority date.”

The court elaborated “Although the specification disclosed just one humanized anti-CGRP antagonist antibody, it also disclosed several murine versions and prior-art methods of humanization—against a backdrop of antiCGRP antagonist antibodies (and methods of making them) being well known and humanization being routine.” In other words, the murine antibodies were still relevant and the jury could properly have considered them.

Thus, I do not read the court as holding that the claims pass 112 muster merely because they are method of use claims, but pass muster because based on the evidence (including Lilly’s arguments in the PTAB) a reasonable jury could have found written description support for the full genus. Indeed, the court stated the “jury therefore could have reasonably found that the specification disclosed a representative number of species of humanized anti-CGRP antagonist antibodies for purposes of the claimed invention, thus rendering JMOL of no written description improper.” In other words, in my opinion the court would have reached the same conclusion on 112 if the claims recited the genus of antibodies themselves (those claims simply would have been unpatentable over the prior art).

The court also stated that “critically, a skilled artisan would have understood from the specification that all humanized anti-CGRP antagonist antibodies treat headache.” It also noted elsewhere that Lilly did not dispute that “a reasonable jury could have found that a skilled artisan would have understood from the specification that all humanized anti-CGRP antagonist antibodies treat headache.” In other words, the court found there was support for the genus of antibodies, and support for their use in treating headaches. I think properly read, the holding shows that claiming a method of use requires an additional showing for 112, not an artificially lower burden.

It appears to me that this was likely a very close call on whether the facts truly show full written description support given a single working example within the scope of the claims, but I would view Teva v. Lilly as being limited to its facts and not representing a broad shift in 112 law for method of use claims.

It’s also a good reminder of the interplay between 112 and obviousness and how arguments for one can come back to bite you on the other. For the defense side specifically, keep in mind that obviousness requires only a single embodiment be obvious whereas 112 support must enable the full scope of the claims, so defendants can thread the needle and argue that one embodiment was obvious over the prior art while other embodiments in the scope of the claim are not enabled in light of the same prior art.