Expert Testimony Allowed as Evidence of Knowledge of PHOSITA

In what Professor Wehgner calls "an amicus brief (at pp. 3-7) to defend its obviousness standard now under attack at the Court in KSR," the Federal Circuit in Alza Corporation v. Mylan Laboratories, Inc., et al. (September 6, 2006), began by reviewing the court's motivation to combine test for obviousness in the U.S.:

As for obviousness, a claimed invention is unpatentable if the differences between it and the prior art are "such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art." 35 U.S.C. § 103(a) (2000); In re Kahn, 441 F.3d 977, 985
(Fed. Cir. 2006) (citing Graham v. John Deere Co., 383 U.S. 1, 13-14, (1966)). Obviousness is a question of law, reviewed de novo, based upon underlying factual questions which are reviewed for clear error following a bench trial. Ruiz v. A.B. Chance Co., 357 F.3d 1270, 1275 (Fed. Cir. 2004). These "underlying factual inquiries includ[e]: (1) the scope and
content of the prior art; (2) the level of ordinary skill in the prior art; (3) the differences between the claimed invention and the prior art; and (4) objective evidence of nonobviousness." In re Dembiczak, 175 F.3d 994, 998 (Fed. Cir. 1999). Similarly, "[t]he presence or absence of a motivation to combine references in an obviousness determination is a pure question of fact," In re Gartside, 203 F.3d 1305, 1316 (Fed. Cir. 2000); accord Winner Int’l Royalty Corp. v. Wang, 202 F.3d 1340, 1348 (Fed. Cir. 2000), as is the presence or absence of a "reasonable expectation of success" from making such a combination, Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1165 (Fed. Cir. 2006). Because "a patent retains its statutory presumption of
validity, see 35 U.S.C. § 282, . . . the movant retains the burden to show the invalidity of the claims by clear and convincing
evidence as to underlying facts." McGinley v. Franklin Sports, Inc., 262 F.3d 1339, 1349 (Fed. Cir. 2001) (internal quotations omitted).

In Graham, the Court held that that the obviousness analysis begins with several basic factual inquiries: "[(1)] the scope and content of the prior art are to be determined; [(2)] differences between the prior art and the claims at issue are to be ascertained; and [(3)] the level of ordinary skill in the pertinent art resolved." 383 U.S. at 17. After ascertaining these facts, the Court held that the obviousness vel non of the invention is then determined "against th[e] background" of the Graham factors. Id. at 17-18 (emphasis added). Clearly, the Court recognized the importance of guarding against hindsight, as is evident in its discussion of the role of secondary considerations as "serv[ing] to guard against slipping into use of hindsight and to resist the temptation to read into the prior art the teachings of the invention in issue." Id. at 36.

The Court of Appeals for the Federal Circuit’s and its redecessor’s "motivation to combine" requirement likewise prevents statutorily proscribed hindsight reasoning when determining the obviousness of an invention. Kahn, 441 F.3d at 986 ("[T]he ‘motivation-suggesting-teaching’ requirement protects against the entry of hindsight into the obviousness analysis."); In re Fridolph, 30 CCPA 939, 942 (1943) ("[I]n considering more than one reference, the question always is: does such art suggest doing the thing the [inventor] did."). According to the "motivation-suggesting-teaching" test, a court must ask "whether a person of ordinary skill in the art, possessed with the understandings and knowledge reflected in the prior art, and motivated by the general problem facing the inventor, would have been led to make the combination recited in the claims." Kahn, 441 F.3d at 988 (citing Cross Med. Prods., Inc., v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1321-24 (Fed. Cir. 2005)).

This requirement has been developed consistent with the Supreme Court’s obviousness jurisprudence as expressed in Graham and the text of the obviousness statute that directs us to conduct the obviousness inquiry "at the time the invention was made" 35 U.S.C. §103. As we explained in Kahn,

The motivation-suggestion-teaching test picks up where the analogous art test leaves off and informs the Graham analysis. To reach a non-hindsight driven conclusion as to whether a person having ordinary skill in the art at the time of the invention would have viewed the subject matter as a whole to
have been obvious in view of multiple references, the Board must provide some rationale, articulation, or reasoned basis to explain why the conclusion of
obviousness is correct. The requirement of such an explanation is consistent with governing obviousness law . . . .

441 F.3d at 987. We further explained that the "motivation to combine" requirement "[e]ntails consideration of both the ‘scope and content of the prior art’ and ‘level of ordinary skill in the pertinent art’ aspects of the Graham test." Id. at 986.

At its core, our anti-hindsight jurisprudence is a test that rests on the unremarkable premise that legal determinations of obviousness, as with such determinations generally, should be based on evidence rather than on mere speculation or conjecture. Our court’s analysis in Kahn bears repeating:

A suggestion, teaching, or motivation to combine the relevant prior art teachings does not have to be found explicitly in the prior art, as "the teaching,
motivation, or suggestion may be implicit from the prior art as a whole, rather than expressly stated in the references. . . . The test for an implicit showing
is what the combined teachings, knowledge of
one of ordinary skill in the art, and the nature of the problem to be solved as a whole would have suggested to those of ordinary skill in the art."
However, rejections on obviousness grounds cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning
with some rational underpinning to support the legal conclusion of obviousness. This requirement is as much rooted in the Administrative Procedure Act [for our review of Board determinations], which
ensures due process and non-arbitrary decisionmaking, as it is in § 103.

441 F.3d at 987-88 (quoting In re Kotzab, 217 F.3d 1365, 1370 (Fed. Cir. 2000)) (citations omitted) (emphases added)). There is flexibility in our obviousness jurisprudence because a motivation may be found implicitly in the prior art. We do not have a rigid test that requires an actual teaching to combine before concluding that one of ordinary skill in the art would
know to combine references. This approach, moreover, does not exist merely in theory but in practice, as well. Our recent decisions in Kahn and in Cross Medical Products amply illustrate the current state of this court’s views. See Kahn, 441 F.3d at 988 (affirming the PTO’s obviousness finding, explaining that a motivation to combine may be found in implicit factors, such as the "knowledge of one of ordinary skill in the art, and [what] the nature of the problem to be solved as
a whole would have suggested to those of ordinary skill in the art"); Cross Med. Prods., 424 F.3d at 1322 (reversing a district court ruling of nonobviousness and explaining that "the motivation to combine need not be found in prior art references, but equally can be found in the knowledge generally available to one of ordinary skill in the art" such as knowledge of a problem to be solved).

In conclusion, our approach has permitted us to continue to address an issue of law not readily amenable to bright-line rules, as we recall and are guided by the wisdom of the Supreme Court in striving for a "practical test of patentability." Graham, 383 U.S. at 17.

The case involved a generic version of the once-a-day extended release formulation of the anti-incontinence drug oxybutynin, which Alza had patented and was marketing as Ditropan XL®. According to Judge Gajarasa,

As an initial matter, we agree with the district court that "on a
purely mechanical level, a person of ordinary skill in the art would have a reasonable expectation of success of manufacturing a 24 hour controlled-release oxybutynin formulation . . . . once motivated to use oxybutynin." Id. at 739.
For example, Wong teaches a rate adjustable extended release dosing technology and release rates falling within the claimed parameters. Baichwal and Wong likewise teach ways of achieving slow rates of release, with Baichwal actually teaching extended-release oxybutynin, although arguably not as slowly as is claimed in the ’355 patent.

. . . it is essential to recognize that, as we have explained above, under our non-rigid "motivation-suggesting-teaching" test, a suggestion to combine need not be found in the prior art. See Cross Med. Prods., 424 F.3d at 1322 ("[T]he motivation to combine need not be found in prior art references, but equally can be found in the knowledge generally available to one of ordinary skill in the art . . . ."). Accordingly, where the testimony of an expert witness is relevant to determining the knowledge that a person of ordinary skill in the art would have possessed at a given time, this is one kind of evidence that is pertinent to our evaluation of a prima facie case of obviousness. We now turn to consider whether the relevant evidence, including
the expert testimony and the prior art, when viewed as a whole supports the findings of the district court. We conclude that the findings of the district court were not clearly erroneous.

Mylan’s expert, Dr. Amidon, testified that based on its lipophilicity, he would "expect oxybutynin to be a highly permeable" compound that is "rapidly absorbed" along the length of the GI tract, including the colon. Later, when hallenged about the predictive value of lipophilicity, Dr. Amidon explained, "I would say there were some unknowns, but again lipophilic drugs would be well absorbed. That would be—that was the general understanding at the time."

Although Alza argues that two prior art references "decisively undercut Dr. Amidon’s hindsight opinion," these references are in fact not inconsistent with the general principle that the extent of a drug’s colonic absorption correlates with its lipophilicity. Indeed, the first reference, a 1990 publication in the Journal of Pharmaceutical Sciences, states that "[i]n general, the more lipophilic drugs were transported rapidly." P. Artursson, Epithelial Transport of Drugs in Cell Culture. I: A Model for Studying the Passive Diffusion of Drugs over Intestinal Absorptive (Caco-2) Cells. 79 J. Pharm. Sci. 476, 481 (1990). Alza, however, cites this reference narrowly for its observation that a highly lipophilic analog of a particular drug did not follow the general rule that lipophilic drugs were transported more quickly. Id. Granted, the But the mere fact that the colonic absorption rate of a drug may be predicted most precisely by using "many factors," rather than "lipophilicity" alone, does not negate the general predictive utility of lipophilicity in estimating the extent of colonic absorption. authors admit that "[t]he reason for this [deviation] is currently unknown," and they postulate that it may be related to a physicochemical factor other than lipophilicity, namely steric hindrance.

Far from teaching away or detracting from the weight of Dr. Amidon’s testimony, these prior art references, taken as a whole, are entirely consistent with the finding that in 1995 a person of ordinary skill in the art would have expected a general, albeit imperfect, correlation between a drug’s lipophilicity and its colonic absorptivity. Accordingly, we cannot perceive clear error in the district court’s factual findings that while colonic absorption was not guaranteed, the evidence, viewed as a whole, is clear and convincing that a person of ordinary skill in the art would nonetheless have perceived a reasonable likelihood of success and that she would have been motivated to combine prior art references to make the claimed invention.

Likewise, we find no error in the district court’s consideration of secondary indicia of obviousness. We therefore affirm its legal conclusion of obviousness, finding the district court to have correctly held that Mylan met its burden of overcoming the presumption of validity that attaches to an issued patent.

More on overactive bladder here.