For an excellent paper on inherency, see Dan Burk and Mark Lemley's article, coincidentally titled, "Inherency," published in 2005:
Inherency is also perhaps the most elusive doctrine in all of patent law. The cases appear to flatly contradict each other, are often accompanied by dissents, and in the last three years alone have triggered one abortive en banc rehearing and strong calls for a second. In particular, the courts have split sharply over whether an element can be inherent in a prior art reference even if people of ordinary skill in the art do not appreciate the existence of that element.
In this Article, we argue that this confusion is largely unnecessary. While many courts have recited as gospel the idea that inherency requires knowledge or appreciation of the inherent element, in no case does the application of the inherency doctrine actually turn on knowledge of the element. Rather, the inherency cases are all ultimately about whether the public already gets the benefit of the claimed element or invention. If the public already benefits from the invention, even if they don't know why, the invention is inherent in the prior art. If the public doesn't benefit from the invention, there is no inherency.
IPBiz notes that the article by Burk and Lemley appears in 47 Wm and Mary L. Rev. 371 (Nov. 2005) and does mention the Schering v. Geneva decision (339 F.3d 1373 (Fed. Cir. 2003)):
Some commentators have come to the conclusion that after Schering, the only factor required for inherency is proof that the thing was in fact present, n42 but that overstates the case.
Most notable is the decision in Schering Corp. v. Geneva Pharmaceuticals, Inc. n49 Schering patented loratadine, branded as the allergy medicine Claritin, and later patented a metabolite of loratadine that is inherently produced in the human body when loratadine is ingested. n50 When Schering's patent on loratadine expired, Schering began suing generics who copied loratadine after the first patent expired for violating the newer metabolite patent. n51
Rather, the court found the metabolite patent inherently anticipated
because the public would necessarily obtain the benefit of the metabolite by
ingesting and metabolizing loratadine. n55
Schering and the rejection of Elan seem to have set the Federal
Circuit firmly on the right course, recognizing that knowledge is not required
In footnote 7, Burk/Lemley cite Todd R. Miller, Patented Compounds Inherently Coproduced as Trace Impurities: Issues of Inherent Anticipation and Literal Infringement, 32 AIPLA Q.J. 425, 442 (2004) (identifying a nine-part test attributable to another author)
Footnote 42 recites: See, e.g., Miller, supra note 7, at 452-53; Alloway, supra note
7, at 86-87.
Footnote 55 directs us to 339 F.3d at 1380, and DOES NOT include any quoted text.
Of Elan, footnote 8 observes: Elan Pharms., Inc. v. Mayo Found. for Med. Educ. & Research, 314 F.3d 1299, 1299 (Fed. Cir. 2002) (en banc) (vacating an earlier panel
opinion and taking the case en banc). The en banc appeal was dismissed when the
panel wrote a new opinion that did not rely on inherency. Elan Pharms., Inc. v.
Mayo Found. for Med. Educ. & Research, 346 F.3d 1051, 1052 (Fed. Cir. 2003).
See also footnote 10 of Festo, Foreseeability, and the Wright Brothers, IPT, page 8, February, 2004: The 1914 resurrection of the Langley Aerodrome in the Wright Brothers saga shows how difficult it is to prove what was, and was not, known at a particular point in time. In an inherent anticipation context, see
Schering v. Geneva, 339 F3d 1373 (CAFC 2003).
See also PETER D. SMITH, ANTICIPATING TOO MUCH: WHY THE COURT SHOULD AVOID EXPANDING THE DOCTRINE OF INHERENT ANTICIPATION, 61 N.Y.U. Ann. Surv. Am. L. 823 (2006):
In 1991, the Federal Circuit decided the seminal case relating to
inherent anticipation, Continental Can Co. USA v. Monsanto Co. n42 This case
involved a patent, the '324 patent, entitled "Ribbed Bottom Structure for Plastic
Container," an invention for a "plastic bottle whose bottom structure
has sufficient flexibility to impart improved impact resistance, combined
with sufficient rigidity to resist deformation under internal pressure." n43
One claimed feature of the '324 patent was that its ribs were hollow. n44
[Of the Schering matter] Furthermore, it was undisputed that when the '716 patent application was filed, one of ordinary skill in the art would not have recognized that administration of loratadine to humans results in the production of DCL n118 so it could not be said that this knowledge was in the public domain.
It explained that "anticipation requires only an enabling disclosure"
so the relevant question [*845] was whether the '233 patent enabled DCL. n128
It concluded that because "the inherent result of administering loratadine to a patient is the formation of DCL[,] the '233 patent... provides an enabling disclosure
for making DCL." n130
Judge Lourie questioned the court's finding of enablement in the
'233 patent for the production of DCL. The judge acknowledged that were loratadine
"in actual public use prior to the filing of [*846] a patent application
on its metabolite, the metabolite will also have been in public use and hence
will be unpatentable." n137 However, Judge Lourie believed that the fact that
the "patent simply included a minimal, boilerplate statement of how to use"
loratadine, i.e. administering the drug to humans, was "hardly an
enabling disclosure of how to make any metabolites, whatever they might turn out
to be, sufficient to anticipate them by inherency." n138 [IPBiz note: the "benefit to the public/public use" argument advanced by Judge Lourie was rejected by the CAFC, not adopted by the CAFC.]
IPBiz notes that Smith did NOT cite the Lemley/Burk article. Smith DID cite a 1999 article by LBE:
Lawrence B. Ebert wrote in November 1999 that Atlas Powder stands for the proposition that "one can't patent 'scientific understanding' of that which was already being done." n70 It is possible to read these cases narrowly, merely limiting the Continental Can test when the inherent element is solely the understanding of the process which is already occurring in the prior art.
LBE appreciates the citation to the 1999 article. Just to further refine, here is some text from "Inherent Difficulties," Intellectual Property Today, page 28 (November 1999)-->
To give fuller context to the quote by Smith, here is more text from the 1999 article:
In this, Atlas Powder appears as a "scientific understanding"
case much as In re King. One can't patent "scientific understanding" of that which
already was being done. Although the particular prior art documents did NOT
explicitly recognize that air may act as the sole sensitizer (absence of
subjective knowledge of the authors of the prior art), the documents taught
explosive compositions in which air did act as a sole sensitizer, as measured by
objective knowledge. Thus, it is true that the recognition that interstitial and
porous air were inherent must be measured against the knowledge of one of
ordinary skill. The case of Mehl/Biophile Int. v. Sandy Milgraum 99-1038
(decided Sept. 30, 1999) contains the same references to Titanium Metals and In re
King as does Atlas Powder. n5 At issue in Mehl was a method of hair depilation,
comprising certain steps. The CAFC again found inherency, although there was an
additional argument not present in Atlas Powder. "Where, as here, the result
[depilation] is a necessary consequence of what was deliberately intended, it is of
no import that the article's authors did not appreciate the results. See W. L.
Gore & Assocs. v. Garlock, Inc., 721 F.2d 1540, 1548, 220 USPQ 303, 309 (Fed.
And here is the buckyball hypo:
To illustrate one issue in the interpretation of Continental Can,
consider the discovery of buckyballs. In 1984, workers at Exxon disclosed the
existence of C60, with the formula as determined by mass spectrometric
measurement n6 and a way to make said C60. (J. Chem. Phys., 1984, 81, 3322). They did not disclose the correct structure of C60; Professors Smalley and Kroto
proposed the structure of C60 to be that of a truncated icosahedron in 1985. This
was not known to be correct until after the work of Huffman and Kratschmer in
1990. Now, assuming that the synthesis of Exxon always led to C60 with the
icosahedral structure, would a patent claim to C60 in 1990 (with the truncated
icosahedral structure) be inherently anticipated by the Exxon work in 1984, even
though no one knew the structure in 1984, and in fact could not have proved the
structure until 1990? Assuming that one of ordinary skill would recognize the
inherent property, albeit at a later date, one might think there would be
inherent anticipation. (Of course, a 1990 claim to merely C60 would be
explicitly anticipated by the written description and enablement of the 1984
reference.) IPBiz notes that, in this hypo, the public was not obtaining any "benefit" from buckyballs prior to 1990 (benefit post 1990 is not clear either), but IPBiz reiterates the inherent anticipation conclusion, in spite of Burk/Lemley.
The article "Inherent Difficulties" cited In re King, 801 F.2d 1324: King was an appeal to the CAFC of a Board rejection for anticipation. The claim at issue in King was to a method of enhancing in a predetermined way color effects produced by ambient light while controlling light intensity comprising several steps. The Board established a prima facie case of anticipation, based on inherency, n4 and the appellant lost for failure to rebut the case. 801 F.2d at 1327. Issues in King are not unrelated to certain rejections of claims of Thomson over Hogan and Williams in the current re-examination of the Thomson / WARF patents concerning human embryonic stem cells.
In Can You Hear Me, Major Tom?, Intellectual Property Today, page 32 (June, 2005), LBE wrote about SmithKline Beecham v. Apotex:
At trial, Apotex argued that a prior art process (nominally making PHC anhydrate)
inherently made SmithKline's PHC hemihydrate (claimed in US 4,721,723), but
Apotex could not prove precisely when PHC hemihydrate came into existence.
Citing to Schering v. Geneva, 339 F.3d 1373, 1377 (CAFC 2003), the CAFC
reiterated that inherent anticipation does not require a person of
ordinary skill to recognize the inherent disclosure in the prior art at the time
of the prior art.n9 The CAFC adjusted what Apotex needed to prove. Apotex did
not need to prove that it was impossible to make the anhydrate without
hemihydrate; Apotex needed to show that the natural result flowing from making the
anhydrate was the hemihydrate. Put differently, the CAFC said it was irrelevant
if pure anhydrate [without hemihydrate] could be made using the prior art
reference; the CAFC said it was enough if the prior art disclosed and enabled a way to make the anhydrate that naturally results in the hemihydrate. Schematically, it is sufficient if there is one pathway that naturally (inevitably?) makes
the hemihydrate, even if there is another pathway that does not make the
hemihydrate. Ironically, it was evidence submitted by SmithKline that
led to the conclusion that practicing the prior art naturally results in the
production of the hemihydrate.
[IPBiz note: this undercuts the Burk/Lemley conjecture about "public obtaining benefit," and, of course, was published BEFORE 47 Wm and Mary L. Rev. 371 (Nov. 2005)]
***To get back to beginning, one might take issue with the assertion in the 271 blog of an "excellent paper on inherency."