McDonnell Boehnen Hulbert & Berghoff LLP

On May 20th, Junior Party the University of California, Berkeley; the University of Vienna; and Emmanuelle Charpentier (collectively, "CVC") filed their Substantive Preliminary Motion No. 2 in Interference No. 106,127 (which names ToolGen as Senior Party), asking the Patent Trial and Appeal Board to deny ToolGen benefit of priority to U.S. Provisional Application No. 16/717,324, filed October 23, 2012 ("P1"), pursuant to 37 C.F.R. §§ 41.121(a)(1)(ii) and 41.208(a)(3) and Standing Order ¶ 208.4.1.  The significance of the Board granting this motion would be that CVC would be Senior Party, with all the presumptions benefiting from Senior Party status.  On July 5th, ToolGen filed is Opposition to this Motion.  On August 27th, CVC filed its Reply.

In its Motion No. 2, CVC argued that the Board should deny ToolGen priority benefit to the '324 application because this application does not disclose an operative embodiment falling within the scope of the interference Count, based on party admissions.  Specifically, CVC argued that in the prosecution of the '324 patent application leading to allowance (and declaration of this interference), ToolGen had argued to the Patent Examiner (and PTAB) that "a codon-optimized Cas9 nucleic acid is required for CRISPR-Cas9 to function in eukaryotic cells" and that "a skilled artisan would have no idea what the outcome may be if one were to codon optimize a Cas9 nucleic acid."  This position was consistent with the prokaryotic source of Cas9, and the Board and Examiner relied upon these arguments to find allowable claims in the '324 application (now claims designated as corresponding to the Count in this interference) according to CVC.  All such claims require use of a Cas9-encoding nucleic acid that is codon-optimized for expression in eukaryotic cells, and CVC asserted that ToolGen added this limitation to the claims to overcome anticipation and obviousness rejections based on the prior art.

But, CVC argued, ToolGen's '324 application does not disclose a codon-optimized Cas9 nucleic acid, nor (by ToolGen's own argument according to CVC) would the skilled worker be able to discern such a nucleic acid with any reasonable basis for expecting such an embodiment could be produced using the disclosure in the '324 application.  Accordingly, CVC argued in its motion, ToolGen cannot in this interference renounce these arguments and rely on the priority date of the '324 patent to constitute a constructive reduction to practice for eukaryotic CRISPR-Cas9 embodiments falling within the scope of the interference Count.  Thus, according to CVC, the Board should deny ToolGen priority benefit to the '324 application (and redeclare the interference naming CVC as Senior Party).  The brief contained examples from the '324 prosecution history and at oral argument before the Board in support of its allegations.

ToolGen, characterizing CVC's arguments (as did CVC, citing Zedner v. United States, 547 U.S. 489 (2006), and Springs Window Fashions LP v. Novo Industries, L.P., 323 F.3d 989, 995 (Fed. Cir. 2003)) as sounding in judicial estoppel, argued this is a "misrepresentation of the prosecution history" and that the '324 application provides a constructive reduction to practice of eukaryotic CRISPR as defined under CVC's portion of the Count in this interference (and that CVC does not effectively challenge this disclosure) but not ToolGen's portion of the Count. ToolGen affirmatively argued that the '324 application "describes a successful experiment using a codon-optimized nucleic acid encoding Cas9 to yield a Cas9 protein complex that functions in eukaryotes to cleave DNA" in support of this assertion.  But more fundamentally, ToolGen argued, Count 1 in the interference does not require codon-optimized Cas9 as part of a eukaryotic CRISPR complex and thus CVC's argument (and Motion) should fail.  The Opposition then addressed the issues raised by CVC, most tellingly setting forth what it contended was a proper explication of the colloquies with the Board during ex parte prosecution that did not support CVC's estoppel arguments.

In it Reply, CVC reiterates its argument that P1 does not disclose a codon-optimized Cas9 species and that their allowed claims depend on arguments made in ex parte prosecution that eukaryotic CRISPR was dependent on such species and that codon-optimization was unpredictable.  Thus, CVC continues to contend, failure to describe a codon-optimized Cas9 protein is fatal to ToolGen's priority claim.  And, according to CVC, ToolGen did not rebut these arguments in its Opposition and thus the Board should grant CVC's motion and deny ToolGen priority benefit to its P1 provisional application.

The brief recaps the legal and evidentiary bases for its arguments, done in the explicatory pattern the interference rules require, selecting quotes from ToolGen's prosecution history that support its arguments and rhetorical flourishes seeming intended to impugn (regarding a ToolGen argument as "an attempt to sow confusion"; "attempts to sidestep the issue").  Of note is CVC's argument that purports to resolve (in its favor) the differing provenance of the "secret sauce" issue with regard to codon-optimized Cas9 ("it is undisputed that during this exchange ToolGen distinguished its claimed invention from the prior art based on codon optimization being required").  The core of CVC's argument, repeated in various incarnations throughout its Reply, is that:

Even if a POSA understood, as ToolGen argues, "reconstituting a nucleic acid sequence using a codon usage table to be codon optimization" or that codon optimization was a routine technique, P1 would at most teach that a Cas9 nucleic acid could be codon optimized.  . . .  But, in view of ToolGen's unpredictability assertions, a POSA would still be in the dark as to the identity of which codon-optimized nucleic acid sequence of the myriad different sequences would express a functional Cas9.  Thus, to be accorded benefit, P1 must describe the specific codon-optimized nucleic acid sequence(s) that would express a functional Cas9.  . . .  P1 fails to do that [citations to the record omitted].

Finally, even the existence of working examples of CRISPR in a eukaryotic cell is not enough, according to CVC, who state "ToolGen's second argument that its P1 describes a codon-optimized Cas9 because it includes working examples is wrong as a matter of law.  . . .  'Proof of a reduction to practice' does not salvage an application that does not otherwise 'describe or identify the invention,'" citing In re Alonso, 545 F.3d 1015, 1021 (Fed. Cir. 2008), according to CVC.