Current Issues in Claim Construction: Drafting and Interpreting Claims After Teva & Citrix - A Report from the APLI:SV, Part 3

By TAP Guest Blogger

Posted on January 5, 2016


This is the third report in a 7-part series from The 16th Annual Advanced Patent Law Institute: Silicon Valley.

The report is written by Kevin Hickey, Microsoft Research Fellow, Berkeley Center for Law & Technology at Berkeley Law School.


A number of presentations at the recent Advanced Patent Law Institute: Silicon Valley (APLI:SV) focused on issues related to claim construction. Claims are the operative part of a patent: they define the legal scope of the invention. How claims are interpreted is thus of critical importance. Several new developments have changed how courts approach this process, raising questions as to how patent prosecutors and litigators should respond to these changes.


The most notable recent development is the Supreme Court’s decision in Teva Pharmaceuticals v. Sandoz, Inc., 135 S. Ct. 831 (2015). Teva overturned longstanding Federal Circuit law that claim construction is a purely legal matter reviewed de novo on appeal. Instead, the Supreme Court held that claim construction, although ultimately a matter of law, may involve “subsidiary factual matters” that are reviewed only for clear error. At APLI:SV, Edward Reines addressed the impact of Teva and how patent attorneys can use the decision to their advantage. Mr. Reines brought attention to a number of claim construction issues that are potentially questions of fact post-Teva, including technical phrases with specialized meaning, ordinary words that have a special meaning to experts in the field, whether a proffered claim construction would exclude the preferred embodiment, and whether 35 U.S.C. § 112(f) applies to the claim. He advised that putting in expert testimony and other extrinsic evidence on these claim construction matters can not only help your side win the issue, but also obtain a more deferential standard of review on appeal.


The other big recent change in claim construction relates to “functional claiming” under 35 U.S.C. § 112(f), which allows patentees to express their inventions in functional terms—“a means for doing X”—instead of specifying a particular structure in the claims. In Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015) (en banc), the Federal Circuit eliminated the “strong” presumption against functional claiming when the patentee does not use the magic word “means.” Instead, claims will be interpreted as functional and subject to § 112(f) whenever the claim term fails to recite a sufficiently definite structure.


Professor Mark Lemley and Lee Van Pelt addressed the impact of Citrix and how courts have applied § 112(f). The key result of Citrix is that patentees can no longer control whether their claims will be subject to § 112(f). Instead, the use of “nonce words” in claims—placeholder terms like “module,” “system,” or “mechanism”—will often trigger § 112(f) regardless of the patentee’s intent. However, courts have not been perfectly consistent on his matter: the panel observed that courts seem to be more likely to apply § 112(f) in the software context vis-à-vis hardware and method claims. Nonetheless, the best advice for patent prosecutors is to avoid nonce words unless one wishes to be subject to § 112(f). After Citrix, then, more care must be taken in drafting to specify definite structures in the claims or specification. Finally, while § 112(f) issues have mostly been litigated in the software context, the functional claiming doctrine will likely not be as circumscribed in the future.


Professor Lisa Ouellette explored a different aspect of § 112: the disclosure and enablement requirements as applied to genus claims in the life sciences. Genus claims seek to cover an entire category of chemical or biological compounds, and must be carefully drafted to avoid § 112 problems. By their nature, genus claims are hard to enable. Under Ariad Pharmaceuticals v. Eli Lilly, 598 F.3d 1336 (Fed. Cir. 2010) (en banc), the patentee must disclosure either a number of representative members (a.k.a. “species”) of the genus, or describe the common structural features of the genus. The challenge of properly enabling a genus claim is particularly acute in the functional claiming context, as shown in the recent decision in AbbVie Deutschland GmbH & Co. v. Janssen Biotech, Inc., 759 F.3d 1285 (Fed. Cir. 2014), which called functional genus claims “inherently vulnerable” to a § 112 challenge. As this route is risky, the better route is specify representative species and/or identify common structural features of the genus in the patent. Even then, the claim might still fail under § 112 if members of the genus do not have predictable properties.


Related Resources

Edward Reines – Claim Construction Post-Teva
Mark Lemley and Lee Van Pelt – Functional Claims
Lisa Ouellette - § 112 Implications for Genus Claims


Read more on the Advanced Patent Law Institute: Silicon Valley


This conference summary was written by Kevin Hickey. Mr. Hickey is the Microsoft Research Fellow, Berkeley Center for Law & Technology at Berkeley Law School.