Recent Federal Circuit jurisprudence reflects a jigsaw puzzle of varied and divergent views of the written-description requirement of 35 U.S.C. 112, ¶ 1 and how written description affects claim construction. Should courts “rewrite” claims to limit their scope to what is disclosed in the specification? Should claim terms always be construed according to their plain meaning (absent a clear intent to the contrary by the inventor)? Should the plain meaning of claim language control, even if the resultant claim scope is broader than the accompanying disclosure, possibly rendering the claim invalid (under the “enablement” requirement)? Should courts even bother with the written-description requirement outside of the (soon to be eliminated) priority context, and instead focus on enablement?
In Ariad Pharms. Inc. v. Eli Lilly & Co., 598 F.3d 1336 (Fed. Cir. 2010) (en banc), fuzzy battle lines were drawn between the proponents of a plain-meaning rule as applied to broad claim terms and the use of limited disclosures to narrowly construe claims. In Ariad, the majority of the U.S. Court of Appeals for the Federal Circuit ruled that written description is a separate and distinct requirement imposed by § 112, ¶ 1, independent from the enablement requirement, but conceded that in some predictable arts, the difference between the two may not be so easy to decipher. The majority in Ariad held that claims to a specific inhibitor of activity by NF-kB (a protein complex that controls the transcription of DNA) were invalid because the specification did not disclose any working or prophetic examples of the methods that achieve the specific claimed biologic activity — disclosure of a hypothetical class of compounds that might achieve the desired outcome was insufficient.
