In a decision denying institution, the PTAB shot down a series of arguments that effectively tried to shoehorn into an IPR issues of indefiniteness. Carefusion Corp. v. Baxter Int’l, Inc. (IPR 2016-01456, Feb. 6, 2017).
35 U.S.C. § 311(b) limits IPRs to only grounds “that could be raised under section 102 or 103 and only on the basis of prior art consisting of patents or printed publications.” This excludes instituting an IPR based on an assertion that the patent claims are indefinite. However, the PTO requires that petitioners include a construction of any challenged claim. 37 C.F.R. § 42.104(b)(3).
The pairing of the statute and the rule seemed to allow a way to slip a challenge to the definiteness of the claims into an IPR. Certainly during the run up to America Invents Act implementation, I had my fair share of discussions with fellow law students about the holes in the statute. The strategy employed by Carefusion is one that came up often: when proposing a claim construction, argue that the claims cannot be construed and are therefore indefinite. If needed, simultaneously, the petitioner would propose a backup claim construction for use in assessing § 102 or § 103 issues.
Specifically, Carefusion asserted that the means-plus-function limitations in US 5,782,805 lacked a corresponding structure in the specification. The claims would therefore be indefinite. In the alternative, Carefusion agreed to use Baxter’s proposed constructions from parallel litigation for the purposes of the IPR only.
The PTAB here did not bite. Although there are a few methods it could have used to discard the argument (e.g., denying for failure to comply with procedural requirements), it chose to reach the merits of the patentability argument. But having rejected the petitioner’s claim constructions, it took little effort to conclude that the petition had failed to demonstrate unpatentability because it’s arguments were based on faulty premises.
The statute prohibits consideration of indefiniteness, so this seems to be the right result. But it does raise the possibility that indefinite patent claims are insulated from attacks in IPR proceedings; a thoroughly bizarre result.
On a final note, the PTAB rejected Carefusion’s alternative claim constructions because “for IPR purposes only” was not sufficient acceptance of the construction. Nonetheless, for some claim constructions, the PTAB went on to discuss why the corresponding structure was not sufficient. Whether these factual conclusions end up mattering in the parallel court proceedings will be interesting to watch.