On December 9, 2020, the U.S. Court of Appeals for the Federal Circuit (Federal Circuit) heard oral argument in a pharmaceutical patent case, Amgen Inc. v. Sanofi, Aventisub LLC.
Amgen sued Sanofi and Regeneron Phamaceuticals, Inc., alleging their competing drug, Praluent, infringed Amgen”™s patents for Repatha. Amgen”™s patents are related to a genus of antibodies called PCSK9 inhibitors, which help patients with LDL, a bad cholesterol, who have difficulty getting their condition under control with widely used statins such as Pfizer Inc.”™s Lipitor.
A lower federal trial court found Amgen”™s two patents should never have been granted because it would take an undue experiment and would not enable a skilled artisan to recreate the genus of antibodies claimed by the patents at issue.
Oral Argument at Federal Circuit
The court considered arguments from both parties regarding the enablement requirement with respect to antibody claims.
Before Amgen”™s presentation of arguments, Judge Lourie commented that the claims are directed to composition of matter claims that were claimed by function rather than structure. Further, Judge Lourie indicated, the district court found that no structure-function relationship would eliminate the need for undue experimentation and therefore lack of enablement.
Disagreeing that the claims were claimed by function and not structure, Amgen responded that it is unrelated to the issue. Amgen asserted that two ”anchor antibodies” spanned the full area of one spot in the PCSK9 antibody and argued that one of ordinary skill in the art can identify all of the at most 400 distinct antibodies that bind anywhere on that one spot.” Further, he argued, identifying the antibodies to those that bind to the sweet spot could be done without undue experimentation, with commonly available laboratory resources and the basic research tools of the field of antibody research.
”I”™m having trouble seeing where your road map and your examples get you to enablement of the full scope of the claims,” Chief Judge Sharon Prost said.
Judge Lourie emphasized that the district court was concerned that the claim did not provide guidance on predicting whether an antibody would bind. Amgen responded that antibody scientists as persons with ordinary skill in the art would understand that once you make the sequence you know to which site they will bind, and that the specification provided guidance on how to make each of the 400 distinct antibodies.
Judge Prost also asked how the patent road map encompassed Sanofi”™s alleged infringing antibodies. Judge Prost said these infringing antibodies seemed to function differently from those claimed by binding a different number of antibodies. Amgen responded that expert testimony indicated no antibody scientist would consider the competitor antibodies to be of a different class from those created by the patent road map.
Sanofi emphasized the number ”400” was unsupported, responding to Amgen”™s arguments, and argued that this ”400” number was not in the district court”™s opinion because this number was never presented to the district court. When asked how many antibodies would accomplish the function if the patent road map was used, Sanofi argued Amgen”™s inventor replied ”I don”™t know a specific number” and Amgen”™s expert answered ”I can”™t give you a number on what the total is.”
Judge Lourie asked to Sanofi on why the enablement requirement would not have been met in this case when the written description requirement has been met. Sanofi responded by arguing that when you have a functional limitation, too many candidates, and you would have to test each and every one to see which ones work, which is a typical example of undue experimentation. According to the district court, Sanofi argued, ”the fact that you knew there [was] gold in the hills and that you knew how to use a pan to find it, [that] doesn”™t mean you are entitled to every ounce of gold in every square mile of the California countryside.”
Judge Hughes asked why requiring a large quantity of experimentation would be considered undue experimentation if qualitatively the experimentation required could be minimal and easy. Sanofi responded by arguing that Amgen”™s own expert testified that testing ”millions and millions of antibodies to see whether they would work . . . would be ”˜an enormous amount of work”™ and more than any scientist would even contemplate doing.”
Judge Hughes then asked whether a genus claim with regard to antibodies should be able to be claimed functionally in any way. Sanofi did not give a definite position to the inquiry. Sanofi argued that there may be a case where function dictates structure sufficiently in the antibody field to cross the threshold of predictability, but that it was not the case in this set of facts.
Amgen replied that, given the structure and the specific one spot in the PCSK9 antibody, one would expect that a limited number of antibody candidates would result from the patent road map. Amgen also argued that an expert estimated somewhere around 100 antibodies, and Amgen conservatively argued that this number could be 400.
Judge Hughes asked why, if millions and millions of tests were required to see if the antibody binds and blocks, that situation would not be undue experimentation. Amgen replied that, while he believed that number appears to be extreme, experimentation would not be undue because of the low risk of experimental failures. In this case, the enablement of a process is defeated only when such failures are pervasive and frequent. In comparison to prior cases, Amgen argued, claims failed when thousands of tests were expected to fail, and you were searching for one that might work. Here, thousands of tests would be expected to succeed with a possibility of a few variations. ”It”™s only when you have failures that impede your ability to make and use the invention that you have undue experimentation,” Amgen argued. ”Being able to successfully make these products isn”™t undue experimentation, it”™s production.”
This case is interesting in part because it may have implications for the patentability of an anti-body drug, including antibodies to treat COVID-19.
We await a decision by the Federal Circuit.