If one wants to be cynical, I think the big picture takeaway is that an issued patent, even a potentially invalid one, is valuable. This one was issued by pure mistake and it took the CAFC itself to invalidate it. Smaller picture, although the burden of proof remains the same, it still seems worthwhile to identify and submit the best art out there to diffuse its (persuasive) weight during litigation. As an interesting side issue, this case also provides a reminder to be careful in everything you say and avoid unnecessarily characterizing the invention as well as other relevant factors to patentability. In ultimately deciding obviousness, the CAFC used the Applicant’s own arguments asserting enablement against them to establish a heightened level of one of ordinary skill: “The applicant’s arguments during prosecution further buttress our belief that Lupin has raised a substantial question of validity with respect to the ’866 patent. During prosecution the applicant indicated ‘that one skilled in the art would be able to manipulate the processes and formulations of the [prior art] by other methods to obtain the claimed pharmacokinetic parameters of the present invention by routine experimentation.’ … While Shionogi argued, and the district court seemed to accept, that this statement applies only to enablement, we are hard pressed to understand this distinction.”

Background / Facts: Lupin submitted an Abbreviated New Drug Application (ANDA) to the FDA for a generic form of a drug patented by Shionogi (formerly “Sciele Pharma”) and listed in the Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book). Shinogi moved for a preliminary injunction, and Lupin countered with an assertion of invalidity. As it turns out, the PTO in stunning fashion issued claims that were not only rejected by the Examiner but also canceled by the Applicant. In effect, the Applicant took the allowable subject matter of dependent claim 5 and canceled independent claim 1. The Examiner erroneously issued an NOA allowing the canceled version of claim 1, the Applicant dutifully pointed out the error, received a corrected NOA, and yet, the canceled version of claim 1 was issued anyway. Nevertheless, “[o]ther than recognizing that the prosecution history was ‘puzzling,’ the district court did not discuss the prosecution history,” and found the claims to be valid because Lupin faced an “added burden of overcoming the deference that is due to a qualified government agency presumed to have done its job.” Lupin appealed primarily on the theory of a lowered burden of proof due to the clarical error committed by the PTO.

Issue(s): Whether the presumption of validity and the accompanying burden of proof is altered due to case-specific facts.

Holding(s): No. Regardless of whether a reference was previously considered by the PTO or other procedural oddities, the burden of proof is the same: clear and convincing evidence of invalidity. However, new evidence not considered by the PTO “may carry more weight . . . than evidence previously considered by the PTO,” and may “go further toward sustaining the attacker’s unchanging burden.” The fact that references were previously before the PTO, for example, goes to the weight the court or jury might assign to the proffered evidence, but not the burden of proof. The CAFC ultimately found the patent invalid as obvious, but under its own analysis, not merely because the PTO in effect agreed and only issued the patent due to clerical error.

Full Opinion