Federal Circuit issues en banc decision in Ariad v Eli Lilly

On 22nd March 2010 the Federal Circuit sitting en banc upheld a previous panel decision of the court in Ariad Pharmaceuticals, Inc v Eli Lilly and Co (560 F3d 1366 (Fed Cir 2009)). The court’s decision reversed a district court judgment in favour of Ariad Pharmaceuticals and its licensors - the Massachusetts Institute of Technology, the Whitehead Institute and Harvard - holding that the patent claims asserted against Eli Lilly for its drugs Evista and Xigris were invalid for lack of written description.

The panel’s decision, issued on 3rd April 2009, applied existing precedent concerning written description in biotechnology and pharmaceuticals, such as University of Rochester v GD Searle & Co (358 F 3d 916 (Fed Cir 2004)). A concurring opinion in the panel decision from Judge Linn questioned the existence of a written description requirement separate from enablement in determining patentability. The en banc decision focused on this disagreement, reaffirming existing precedent concerning the existence of a separate written description requirement and the "possession" standard for written description.

Ariad’s patent - issued in June 2002 (US Patent 6,410,516) - was based on the discovery of transcription factor NF-kB and the realisation that reduction of NF-kB activity could ameliorate the effects of certain diseases, such as those associated with production of cytokines.

After a 14-day trial, the jury found two claims of the patent infringed by Evista and two claims infringed by Xigris. Claim 95, rewritten in independent form, is exemplary:

 "A method for reducing, in eukaryotic cells, the level of expression of genes which are activated by extracellular influences which induce NF-kB mediated intracellular signaling, the method comprising reducing NF-kB activity in the cells such that expression of said gene is reduced, carried out on human cells."

As can be seen, the claim did not specify what compounds - or indeed if any compound at all - were to be used in practice of the claimed method. On this basis, Ariad sought to distinguish University of Rochester, in which the Federal Circuit held invalid for lack of written description claims drawn to methods of selectively inhibiting COX-2 by administration of unspecified "non-steroidal" compounds which achieved that result.

The Federal Circuit panel explained what it found lacking in the specification, which hypothesised three classes of compounds potentially capable of reducing NF-kB activity without giving specific examples. As to each of these three classes, the court noted the following:
  • Specific inhibitors - the specification gave one example, which was a naturally occurring peptide. However, the DNA sequence for this substance was not in the original application, but was added later.
  • Dominantly interfering molecules - the specification provided no examples and stated that these compounds would work only  "if the DNA binding domain and the DNA polymerase domain of NF-kB are spatially distinct in the molecule" without stating that these domains were actually distinct.
  • Decoy molecules - the specification provided several example structures, but did not describe how to use the molecules to reduce NF-kB activity. The court declined to accept the specification’s prophetic example as sufficient description, characterising it as "not so much an ‘example’ as it is a mere mention of a desired outcome". The decision did not hold that prophetic examples can never provide sufficient written description, but held that the ones here were insufficient.

Accordingly, the panel reversed the judgment entered on the jury verdict and held the asserted claims invalid.

Concurring, Linn joined the panel opinion as supported by existing Federal Circuit precedent, but reiterated his previously expressed disagreement with that precedent. On several occasions in earlier cases, Linn and other members of the Federal Circuit wrote that the written description requirement - as it has come to be applied to hold claims invalid - does not exist as a requirement of patentability that is separate from the enablement requirement. For example, in Enzo Biochem, Inc v Gen-Probe Inc (323 F3d 956 (Fed Cir 2002), three members of the court (Judges Rader, Gajarsa and Linn) expressed this view in dissenting from the denial of rehearing en banc, and a fourth (Judge Dyk) wrote that consideration of the matter en banc was not warranted at the time (given the procedural posture of the case), but that it might be in the future.

In August 2009 the court voted to rehear the appeal en banc, directing that the parties brief whether 35 USC § 112 ¶ 1 contains a written description requirement separate from the enablement requirement, and if so, the scope and purpose of the written description requirement. The Federal Circuit heard oral argument en banc in December 2009.

Latest decision
The March 2010 en banc opinion, written by Judge Lourie, reaffirmed the Federal Circuit’s previous holdings that the written description requirement is separate from the enablement requirement, surveying both Federal Circuit and Supreme Court precedent in reaching this conclusion.

The opinion acknowledged that the written description requirement will at times be largely equivalent to the enablement requirement. It illustrated this with a discussion of In re Ruschig (379 F2d 990 (CCPA 1967)), which is often cited as the first case elaborating a separate written description requirement, in which the claims were amended during prosecution to recite a specific compound that was not described in the specification except to the extent that it was embraced within an originally disclosed genus encompassing about "half a million possible compounds". The court observed that it was merely a question of semantics whether the claim was invalid for not enabling one of ordinary skill in the art to choose the specific compound from the genus, or for not providing written description showing that the inventors possessed knowledge of the specific compound.

The en banc opinion reaffirmed the Federal Circuit’s "fairly uniform standard" under which:

"the test for sufficiency is whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date."

The court acknowledged that this was not the clearest of standards, but elaborated on a few broad principles.

First, a constructive reduction to practice that identifies the claimed invention can satisfy the written description requirement; actual reduction to practice is not necessary. Second, for generic claims, sufficient examples showing features common to the members of the genus must be described. For example, specifications that only describe the problem to be solved, give a few specific examples of useful chemical compounds and do not explain what structural features of the examples solve the problem will be insufficient for a claim to an entire genus of chemical compounds. The court’s analysis was not limited to chemical compounds, but no examples were provided from other fields.

Having resolved the issues of law and affirmed the existence of and standard for written description, the en banc opinion adopted the analysis of the panel decision holding the claims invalid for lack of written description.

Dissenting from the en banc opinion, Rader and Linn wrote that the only written description requirement contained in 35 USC § 112 is equivalent to the enablement requirement. Rader wrote that the court’s holding was inconsistent with the law of claim construction, in that a properly interpreted claim should never enlarge the scope of the invention beyond that described in the specification, and so there should never be a claim that "lacks support" in the rest of the patent and would therefore be invalid for lack of written description. Rader also pointed out that the written description requirement creates problems for pioneering blocking patents, as later developments in the invention may cast doubt on the written description of the original invention where they would not create enablement problems.

Linn’s dissent focused on deficiencies in the majority’s statutory interpretation analysis, stating that it remained unclear what the difference was between the majority’s "possession" standard and the enablement requirement. He wrote:

"[I]f a person of ordinary skill is enabled to make and use a novel and nonobvious invention clearly recited in the claims, I fail to see how that invention can be said to ‘have not been invented’ or be in need of some undefined level of additional description."

Additionally, Linn focused on a particular disagreement with applying the written description test to claims originally included in the patent application, noting precedent that original claims constitute their own description. Without a review of the decision at the Supreme Court, the Federal Circuit’s en banc decision puts to rest any questions over the existence of the written description requirement as a constraint on patentability that is separate from the enablement requirement. It remains to be seen if Supreme Court review will be sought or granted.

As a measure of the importance with which this issue was viewed in the patent field generally, 26 amicus briefs were filed in the en banc proceedings. Among the participants were:
  • The US government.
  • Six pharmaceutical and biotech companies, including Amgen and Glaxo-SmithKline.
  • Six electronics and software companies, including Google, Microsoft and Verizon.
  • Three bar associations including the New York Intellectual Property Law Association.

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