Linking Pigs and Humans through the Enablement Doctrine

By Dennis Crouch

Edwards Lifesciences AG v. CoreValve, Inc. (Fed. Cir 2012)

In an opinion by Judge Newman, the Federal Circuit has sided with the patentee – rejecting the challenger's argument that the patent lacked an enabling disclosure under 35 U.S.C. § 112(1). The claims (and accused infringer activity) are all seemingly focused on using the claimed cardiac valve prosthesis in a human. However, at the time of the patent application, the invention had only been tested in a pig and the human link in the specification was only the statement that "the cardiac valve prosthesis for use in human beings has a corresponding form." (In its brief, CoreValue also notes that none of the pigs survived more than five hours.). See U.S. Patent No. 5,411,552. The real question was whether the conversion to a human prosthesis would require undue experimentation. If not, then the specification is sufficient.

The court writes:

CoreValve [the accused infringer] argues that in no event does testing in pigs enable use in humans. However, it has long been recognized that when experimentation on human subjects is inappropriate, as in the testing and development of drugs and medical devices, the enablement requirement may be met by animal tests or in vitro data. See MPEP §2164.02 ("An in vitro or in vivo animal model example in the specification, in effect, constitutes a 'working example' if that example 'correlates' with a disclosed or claimed method invention."). This general rule has been elaborated in various situations, e.g., In re Brana, 51 F.3d 1560, 1566 (Fed. Cir. 1995) ("one who has taught the public that a compound exhibits some desirable pharmaceutical property in a standard experimental animal has made a significant and useful contribution to the art, even though it may eventually appear that the compound is without value in the treatment in humans"); Scott v. Finney, 34 F.3d 1058, 1063 (Fed. Cir. 1994) ("Testing for the full safety and effectiveness of a prosthetic device is more properly left to the Food and Drug Administration. Title 35 does not demand that such human testing occur within the confines of Patent and Trademark Office proceedings.").

Rather than following any bright-line rule requiring human testing, the court refocused attention on the so-called "Wands factors" of undue experimentation summarized by the court in the case of In re Wands, 858 F.2d 731 (Fed. Cir. 1988). These factors 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,
7. the predictability or unpredictability of the art, and
8. the breadth of the claims.

In this vein, so to speak, the patentee had provided expert trial testimony as to how someone skilled in the art would be able to take the pig results and use them for a human version without undue experimentation. Based upon that testimony, the court was able to confirm that the jury conclusion was based on substantial evidence.

Validity judgment confirmed.

Construing Claims for Enablement: From a doctrinal standpoint, the question of whether a claim is sufficiently enabled should not depend upon the accused infringing activity. In practice that link is regularly found in the caselaw where courts focus the enablement question on activities related to the accused infringement. This case is no different. It turns out that the asserted claims are not expressly limited to a product for use with humans. Rather, the claims are directed toward "a valve prosthesis for implantation in a body channel." Now, the specification does suggest that the problem being addressed deals with people and that suggestion cold potentially limit the claim scope. However, the court does not deal with the real reality that the claims are drafted in a way that would encompass use of the device in a variety of animals – many of them vastly different from a pig. In mind, this comes together to mean that we have a de facto special claim construction for enablement purposes that is used to understand the "full scope" of the claims.

Note:

• The case has an important remedies discussion that will be included in a future post.
• The parallel patent has been already litigated in both Germany and the UK with both cases resulting in non-infringement determinations. The key difference here is that the US courts have more broadly interpreted the claim term "cylindrical" to include shapes that are not really cylindrical. (The relevant portion of the accused device does not have a uniform diameter along its axis). That construction was confirmed on appeal since the specification does not explicitly require constant diameter.
• In regards to the image accompanying this post, do you read from left-to-right or right-to-left?