Examination Guidelines Update: Developments in the Obviousness Inquiry After KSR v.Teleflex, 53643-53660 [2010-21646]

Agencies

• DEPARTMENT OF COMMERCE
• Patent and Trademark Office

[Federal Register Volume 75, Number 169 (Wednesday, September 1, 2010)]
[Notices]
[Pages 53643-53660]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-21646]


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DEPARTMENT OF COMMERCE

 Patent and Trademark Office

[Docket No.: PTO-P-2010-0055]


Examination Guidelines Update: Developments in the Obviousness 
Inquiry After KSR v.Teleflex

AGENCY: United States Patent and Trademark Office, Commerce.

ACTION: Notice.

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SUMMARY: The United States Patent and Trademark Office (USPTO or 
Office) is issuing an update (2010 KSR Guidelines Update) to its 
obviousness guidelines for its personnel to be used when applying the 
law of obviousness under

[[Page 53644]]

35 U.S.C. 103. This 2010 KSR Guidelines Update highlights case law 
developments on obviousness under 35 U.S.C. 103 since the 2007 decision 
by the United States Supreme Court (Supreme Court) in KSR Int'l Co. v. 
Teleflex Inc. These guidelines are intended to be used by Office 
personnel in conjunction with the guidance in the Manual of Patent 
Examining Procedure when applying the law of obviousness under 35 
U.S.C. 103. Members of the public are invited to provide comments on 
the 2010 KSR Guidelines Update. The Office is especially interested in 
receiving suggestions of recent decisional law in the field of 
obviousness that would have particular value as teaching tools.

DATES: Effective Date: This 2010 KSR Guidelines Update is effective 
September 1, 2010.

ADDRESSES: Comments concerning this 2010 KSR Guidelines Update may be 
sent by electronic mail message over the Internet addressed to KSR_Guidance@uspto.gov, or submitted by mail addressed to: Mail Stop 
Comments--Patents, Commissioner for Patents, P.O. Box 1450, Alexandria, 
VA 22313-1450. Although comments may be submitted by mail, the Office 
prefers to receive comments via the Internet.

FOR FURTHER INFORMATION CONTACT: Kathleen Kahler Fonda or Pinchus M. 
Laufer, Legal Advisors, Office of Patent Legal Administration, Office 
of the Associate Commissioner for Patent Examination Policy, by 
telephone at (571) 272-7754 or (571) 272-7726; by mail addressed to: 
Mail Stop Comments Patents, Commissioner for Patents, P.O. Box 1450, 
Alexandria, VA 22313-1450; or by facsimile transmission to (571) 273-
7754, marked to the attention of Kathleen Kahler Fonda.

SUPPLEMENTARY INFORMATION: 
    1. Introduction. The purpose of this 2010 KSR Guidelines Update is 
to remind Office personnel of the principles of obviousness explained 
by the Supreme Court in KSR Int'l Co. v. Teleflex Inc., 550 U.S 398 
(2007) (KSR), and to provide additional guidance in view of decisions 
by the United States Court of Appeals for the Federal Circuit (Federal 
Circuit) since KSR. This body of case law developed over the past three 
years provides additional examples that will be useful to Office 
personnel as well as practitioners during the examination process. 
Although every question of obviousness must be decided on its own 
facts, these cases begin to clarify the contours of the obviousness 
inquiry after KSR, and help to show when a rejection on this basis is 
proper and when it is not.
    This 2010 KSR Guidelines Update does not constitute substantive 
rule making and hence does not have the force and effect of law. It has 
been developed as a matter of internal Office management and is not 
intended to create any right or benefit, substantive or procedural, 
enforceable by any party against the Office. Rejections will continue 
to be based upon the substantive law, and it is these rejections that 
are appealable. Consequently, any failure by Office personnel to follow 
this 2010 KSR Guidelines Update is neither appealable nor petitionable.
    After a review of the principles of obviousness and Office policy 
as reflected in the Manual of Patent Examining Procedure (MPEP), this 
2010 KSR Guidelines Update addresses a number of issues that arise when 
Office personnel consider whether or not a claimed invention is 
obvious. The concepts discussed are grounded in Federal Circuit cases, 
and correlated with existing Office policy as appropriate. A number of 
cases which have been selected for their instructional value on the 
issue of obviousness will be discussed in detail.
    The law of obviousness will continue to be refined, and Office 
personnel are encouraged to maintain an awareness of precedential case 
law from the Federal Circuit and precedential decisions of the Board of 
Patent Appeals and Interferences (Board) in this area. The Office will 
train Office personnel and update the MPEP as necessary to reflect the 
current state of the law.
    2. Principles of Obviousness and the Guidelines. In response to the 
Supreme Court's April 2007 decision in KSR, the Office developed 
guidelines for patent examiners to follow when determining obviousness 
of a claimed invention and published these guidelines in the Federal 
Register and Official Gazette. See Examination Guidelines for 
Determining Obviousness Under 35 U.S.C. 103 in View of the Supreme 
Court Decision in KSR International Co. v. Teleflex Inc., 72 FR 57526 
(Oct. 10, 2007), 1324 Off. Gaz. Pat. Office 23 (Nov. 6, 2007) (2007 KSR 
Guidelines). The 2007 KSR Guidelines have been incorporated in the 
MPEP. See MPEP Sec.  2141 (8th ed. 2001) (Rev. 6, Sept. 2007). The 
purpose of the 2007 KSR Guidelines was to give Office personnel 
practical guidance on how to evaluate obviousness issues under 35 
U.S.C. 103(a) in accordance with the Supreme Court's instruction in 
KSR. The 2007 KSR Guidelines also alerted Office personnel to the 
importance of considering rebuttal evidence submitted by patent 
applicants in response to obviousness rejections.
    The 2007 KSR Guidelines pointed out, as had the Supreme Court in 
KSR, that the factual inquiries announced in Graham v. John Deere, 383 
U.S. 1, 17-18 (1966) (scope and content of the prior art; differences 
between the claimed invention and the prior art; level of ordinary 
skill in the art; and secondary indicia of nonobviousness), remain the 
foundation of any determination of obviousness. It remains true that 
``[t]he determination of obviousness is dependent on the facts of each 
case.'' Sanofi-Synthelabo v. Apotex, Inc., 550 F.3d 1075, 1089 (Fed. 
Cir. 2008) (citing Graham, 383 U.S. at 17-18 (1966)). As for the 
reasoning required to support an obviousness determination, the 2007 
KSR Guidelines noted that the teaching-suggestion-motivation (TSM) test 
was but one possible approach. The 2007 KSR Guidelines identified six 
other rationales gleaned from the KSR decision as examples of 
appropriate lines of reasoning that could also be used. The six other 
rationales identified in the 2007 KSR Guidelines are: (1) Combining 
prior art elements according to known methods to yield predictable 
results; (2) simple substitution of one known element for another to 
obtain predictable results; (3) use of a known technique to improve 
similar devices, methods, or products in the same way; (4) applying a 
known technique to a known device, method, or product ready for 
improvement to yield predictable results; (5) obvious to try--choosing 
from a finite number of identified, predictable solutions, with a 
reasonable expectation of success; and (6) known work in one field of 
endeavor may prompt variations of it for use in either the same field 
or a different one based on design incentives or other market forces if 
the variations are predictable to one of ordinary skill in the art. Any 
rationale employed must provide a link between the factual findings and 
the legal conclusion of obviousness.
    It is important for Office personnel to recognize that when they do 
choose to formulate an obviousness rejection using one of the 
rationales suggested by the Supreme Court in KSR and discussed in the 
2007 KSR Guidelines, they are to adhere to the instructions provided in 
the MPEP regarding the necessary factual findings. However, the 2007 
KSR Guidelines also stressed that while the Graham inquiries and the 
associated reasoning are crucial to a proper obviousness determination, 
the Supreme Court in KSR did not place any limit on the particular 
approach to be taken to formulate the line of reasoning.

[[Page 53645]]

In other words, the KSR decision is not to be seen as replacing a 
single test for obviousness--the TSM test--with the seven rationales 
listed in the 2007 KSR Guidelines. See MPEP Sec. Sec.  2141 and 2143 
(8th ed. 2001) (Rev. 8, July 2010) (references to the MPEP are to 
Revision 8 of the 8th Edition of the MPEP unless otherwise indicated). 
It remains Office policy that appropriate factual findings are required 
in order to apply the enumerated rationales properly. If a rejection 
has been made that omits one of the required factual findings, and in 
response to the rejection a practitioner or inventor points out the 
omission, Office personnel must either withdraw the rejection, or 
repeat the rejection including all required factual findings.
    3. The Impact of the KSR Decision. KSR's renewed emphasis on the 
foundational principles of Graham coupled with its abrogation of the 
strict TSM test have clearly impacted the manner in which Office 
personnel and practitioners carry out the business of prosecuting 
patent applications with regard to issues of obviousness. However, 
Office personnel as well as practitioners should also recognize the 
significant extent to which the obviousness inquiry has remained 
constant in the aftermath of KSR.
    In footnote 2 of the 2007 KSR Guidelines, the Office acknowledged 
that ongoing developments in the law of obviousness were to be expected 
in the wake of the KSR decision. That footnote also stated that it was 
``not clear which Federal Circuit decisions will retain their 
viability'' after KSR. See 2007 KSR Guidelines, 72 FR at 57,528 n.2. 
The edition of the MPEP that was current when the KSR decision was 
handed down had made the following statement in Sec.  2144:

    The rationale to modify or combine the prior art does not have 
to be expressly stated in the prior art; the rationale may be 
expressly or impliedly contained in the prior art or it may be 
reasoned from knowledge generally available to one of ordinary skill 
in the art, established scientific principles, or legal precedent 
established by prior case law.

    MPEP Sec.  2144 (8th ed. 2001) (Rev. 5, Aug. 2006) (citing five 
pre-KSR Federal Circuit opinions and two decisions of the Board). The 
KSR decision has reinforced those earlier decisions that validated a 
more flexible approach to providing reasons for obviousness. However, 
the Supreme Court's pronouncement in KSR has at the same time clearly 
undermined the continued viability of cases such as In re Lee, 277 F.3d 
1338 (Fed. Cir. 2002), insofar as Lee appears to require a strict basis 
in record evidence as a reason to modify the prior art.
    The Supreme Court's flexible approach to the obviousness inquiry is 
reflected in numerous pre-KSR decisions, as can be seen in a review of 
MPEP Sec.  2144. This section provides many lines of reasoning to 
support a determination of obviousness based upon earlier legal 
precedent that had condoned the use of particular examples of what may 
be considered common sense or ordinary routine practice (e.g., making 
integral, changes in shape, making adjustable). Thus, the type of 
reasoning sanctioned by the opinion in KSR has long been a part of the 
patent examination process. See MPEP Sec.  2144.
    Although the KSR approach is flexible with regard to the line of 
reasoning to be applied, the 2007 KSR Guidelines and MPEP Sec.  2143 
state: ``The Supreme Court in KSR noted that the analysis supporting a 
rejection under 35 U.S.C. 103 should be made explicit.'' MPEP Sec.  
2143. In Ball Aerosol v. Limited Brands, 555 F.3d 984 (Fed. Cir. 2009), 
the Federal Circuit offered additional instruction as to the need for 
an explicit analysis. The Federal Circuit explained, as is consistent 
with the 2007 KSR Guidelines, that the Supreme Court's requirement for 
an explicit analysis does not require record evidence of an explicit 
teaching of a motivation to combine in the prior art.

    [T]he analysis that ``should be made explicit'' refers not to 
the teachings in the prior art of a motivation to combine, but to 
the court's analysis * * *. Under the flexible inquiry set forth by 
the Supreme Court, the district court therefore erred by failing to 
take account of ``the inferences and creative steps,'' or even 
routine steps, that an inventor would employ and by failing to find 
a motivation to combine related pieces from the prior art.

    Ball Aerosol, 555 F.3d at 993. The Federal Circuit's directive in 
Ball Aerosol was addressed to a lower court, but it applies to Office 
personnel as well. When setting forth a rejection, Office personnel are 
to continue to make appropriate findings of fact as explained in MPEP 
Sec. Sec.  2141 and 2143, and must provide a reasoned explanation as to 
why the invention as claimed would have been obvious to a person of 
ordinary skill in the art at the time of the invention. This 
requirement for explanation remains even in situations in which Office 
personnel may properly rely on intangible realities such as common 
sense and ordinary ingenuity.
    When considering obviousness, Office personnel are cautioned 
against treating any line of reasoning as a per se rule. MPEP Sec.  
2144 discusses supporting a rejection under 35 U.S.C. 103 by reliance 
on scientific theory and legal precedent. In keeping with the flexible 
approach and the requirement for explanation, Office personnel may 
invoke legal precedent as a source of supporting rationale when 
warranted and appropriately supported. See MPEP Sec.  2144.04. So, for 
example, automating a manual activity, making portable, making 
separable, reversal or duplication of parts, or purifying an old 
product may form the basis of a rejection. However, such rationales 
should not be treated as per se rules, but rather must be explained and 
shown to apply to the facts at hand. A similar caveat applies to any 
obviousness analysis. Simply stating the principle (e.g., ``art 
recognized equivalent,'' ``structural similarity'') without providing 
an explanation of its applicability to the facts of the case at hand is 
generally not sufficient to establish a prima facie case of 
obviousness.
    Many basic approaches that a practitioner may use to demonstrate 
nonobviousness also continue to apply in the post-KSR era. Since it is 
now clear that a strict TSM approach is not the only way to establish a 
prima facie case of obviousness, it is true that practitioners have 
been required to shift the emphasis of their nonobviousness arguments 
to a certain degree. However, familiar lines of argument still apply, 
including teaching away from the claimed invention by the prior art, 
lack of a reasonable expectation of success, and unexpected results. 
Indeed, they may have even taken on added importance in view of the 
recognition in KSR of a variety of possible rationales.
    At the time the KSR decision was handed down, some observers 
questioned whether the principles discussed were intended by the 
Supreme Court to apply to all fields of inventive endeavor. Arguments 
were made that because the technology at issue in KSR involved the 
relatively well-developed and predictable field of vehicle pedal 
assemblies, the decision was relevant only to such fields. The Federal 
Circuit has soundly repudiated such a notion, stating that KSR applies 
across technologies:

    This court also declines to cabin KSR to the ``predictable 
arts'' (as opposed to the ``unpredictable art'' of biotechnology). 
In fact, this record shows that one of skill in this advanced art 
would find these claimed ``results'' profoundly ``predictable.''

    In re Kubin, 561 F.3d 1351, 1360 (Fed. Cir. 2009). Thus, Office 
personnel should not withdraw any rejection solely on the basis that 
the invention lies in a technological area ordinarily considered to be 
unpredictable.
    The decisions of the Federal Circuit discussed in this 2010 KSR 
Guidelines

[[Page 53646]]

Update provide Office personnel as well as practitioners with 
additional examples of the law of obviousness. The purpose of the 2007 
KSR Guidelines was, as stated above, to help Office personnel to 
determine when a claimed invention is not obvious, and to provide an 
appropriate supporting rationale when an obviousness rejection is 
appropriate. Now that a body of case law is available to guide Office 
personnel and practitioners as to the boundaries between obviousness 
and nonobviousness, it is possible in this 2010 KSR Guidelines Update 
to contrast situations in which the subject matter was found to have 
been obvious with those in which it was determined not to have been 
obvious. Thus, Office personnel may use this 2010 KSR Guidelines Update 
in conjunction with the 2007 KSR Guidelines (incorporated into MPEP 
Sec. Sec.  2141 and 2143) to provide a more complete view of the state 
of the law of obviousness.
    This 2010 KSR Guidelines Update provides a ``teaching point'' for 
each discussed case. The ``teaching point'' may be used to quickly 
determine the relevance of the discussed case, but should not be used 
as a substitute for reading the remainder of the discussion of the case 
in this 2010 KSR Guidelines Update. Nor should any case in this 2010 
KSR Guidelines Update be applied or cited in an Office action solely on 
the basis of what is stated in the ``teaching point'' for the case.
    4. Obviousness Examples from Federal Circuit Cases. The impact of 
the Supreme Court's decision in KSR can be more readily understood in 
the context of factual scenarios. The cases in this 2010 KSR Guidelines 
Update are broadly grouped according to obviousness concepts in order 
to provide persons involved with patent prosecution with ready access 
to the examples that are most pertinent to the issue at hand. The first 
three groups correspond directly with three of the rationales 
identified in the 2007 KSR Guidelines. These rationales--combining 
prior art elements, substituting one known element for another, and 
obvious to try--have each been the subject of a significant number of 
post-KSR obviousness decisions. The fourth group focuses on issues 
concerning consideration of evidence during prosecution. Office 
personnel as well as practitioners are reminded of the technology-
specific obviousness examples previously posted on the Office's Web 
site at https://www.uspto.gov/web/offices/pac/dapp/opla/ksr/ksr_training_materials.htm.
    Although the other rationales discussed in the 2007 KSR Guidelines 
are not the focus of separate discussions in this 2010 KSR Guidelines 
Update, it will be noted that obviousness concepts such as applying 
known techniques, design choice, and market forces are addressed when 
they arise in the selected cases. The cases included in this 2010 KSR 
Guidelines Update reinforce the idea, presented in the 2007 KSR 
Guidelines, that there may be more than one line of reasoning that can 
properly be applied to a particular factual scenario. The selected 
decisions also illustrate the overlapping nature of the lines of 
reasoning that may be employed to establish a prima facie case of 
obviousness. Although the 2007 KSR Guidelines presented the rationales 
as discrete, self-contained lines of reasoning, and they may indeed be 
employed that way, it is useful to recognize that real-world situations 
may require analyses that may not be so readily pigeon-holed into 
distinct categories.
    A. Combining Prior Art Elements. In discussing the obviousness 
rationale concerning combining prior art elements, identified as 
Rationale A, the 2007 KSR Guidelines quoted KSR and noted that ``it can 
be important to identify a reason that would have prompted a person of 
ordinary skill in the relevant field to combine the elements in the way 
the claimed new invention does.'' KSR, 550 U.S. at 401. In view of the 
cases decided since KSR, one situation when it is important to identify 
a reason to combine known elements in a known manner to obtain 
predictable results is when the combination requires a greater 
expenditure of time, effort, or resources than the prior art teachings. 
Even though the components are known, the combining step is technically 
feasible, and the result is predictable, the claimed invention may 
nevertheless be nonobvious when the combining step involves such 
additional effort that no one of ordinary skill would have undertaken 
it without a recognized reason to do so. When a combination invention 
involves additional complexity as compared with the prior art, the 
invention may be nonobvious unless an examiner can articulate a reason 
for including the added features or steps. This is so even when the 
claimed invention could have been readily implemented.
    Example 4.1. In re Omeprazole Patent Litigation, 536 F.3d 1361 
(Fed. Cir. 2008). Teaching point: Even where a general method that 
could have been applied to make the claimed product was known and 
within the level of skill of the ordinary artisan, the claim may 
nevertheless be nonobvious if the problem which had suggested use of 
the method had been previously unknown.
    The case of In re Omeprazole Patent Litigation is one in which the 
claims in question were found to be nonobvious in the context of an 
argument to combine prior art elements. The invention involved applying 
enteric coatings to a drug in pill form for the purpose of ensuring 
that the drug did not disintegrate before reaching its intended site of 
action. The drug at issue was omeprazole, the generic name for gastric 
acid inhibitor marketed as Prilosec[reg]. The claimed formulation 
included two layers of coatings over the active ingredient.
    The district court found that Astra's patent in suit was infringed 
by defendants Apotex and Impax. The district court rejected Apotex's 
defense that the patents were invalid for obviousness. Apotex had 
argued that the claimed invention was obvious because coated omeprazole 
tablets were known from a prior art reference, and because secondary 
subcoatings in pharmaceutical preparations generally were also known. 
There was no evidence of unpredictability associated with applying two 
different enteric coatings to omeprazole. However, Astra's reason for 
applying an intervening subcoating between the prior art coating and 
omeprazole had been that the prior art coating was actually interacting 
with omeprazole, thereby contributing to undesirable degradation of the 
active ingredient. This degradation of omeprazole by interaction with 
the prior art coating had not been recognized in the prior art. 
Therefore, the district court reasoned that based on the evidence 
available, a person of ordinary skill in the art would have had no 
reason to include a subcoating in an omeprazole pill formulation.
    The Federal Circuit affirmed the district court's decision that the 
claimed invention was not obvious. Even though subcoatings for enteric 
drug formulation were known, and there was no evidence of undue 
technical hurdles or lack of a reasonable expectation of success, the 
formulation was nevertheless not obvious because the flaws in the prior 
art formulation that had prompted the modification had not been 
recognized. Thus there would have been no reason to modify the initial 
formulation, even though the modification could have been done. 
Moreover, a person of skill in the art likely would have chosen a 
different modification even if he or she had recognized the problem.
    Office personnel should note that in this case the modification of 
the prior art that had been presented as an

[[Page 53647]]

argument for obviousness was an extra process step that added an 
additional component to a known, successfully marketed formulation. The 
proposed modification thus amounted to extra work and greater expense 
for no apparent reason. This is not the same as combining known prior 
art elements A and B when each would have been expected to contribute 
its own known properties to the final product. In the Omeprazole case, 
in view of the expectations of those of ordinary skill in the art, 
adding the subcoating would not have been expected to confer any 
particular desirable property on the final product. Rather, the final 
product obtained according to the proposed modifications would merely 
have been expected to have the same functional properties as the prior 
art product.
    The Omeprazole case can also be analyzed in view of the discovery 
of a previously unknown problem by the patentee. If the adverse 
interaction between active agent and coating had been known, it might 
well have been obvious to use a subcoating. However, since the problem 
had not been previously known, there would have been no reason to incur 
additional time and expense to add another layer, even though the 
addition would have been technologically possible. This is true because 
the prior art of record failed to mention any stability problem, 
despite the acknowledgment during testimony at trial that there was a 
known theoretical reason that omeprazole might be subject to 
degradation in the presence of the known coating material.
    Example 4.2. Crocs, Inc. v. U.S. International Trade Commission, 
598 F.3d 1294 (Fed. Cir. 2010). Teaching point: A claimed combination 
of prior art elements may be nonobvious where the prior art teaches 
away from the claimed combination and the combination yields more than 
predictable results.
    The case of Crocs, Inc. v. U.S. International Trade Commission is a 
decision in which the claimed foam footwear was held by the Federal 
Circuit to be nonobvious over a combination of prior art references.
    The claims involved in the obviousness issue were from Crocs' U.S. 
Patent No. 6,993,858, and were drawn to footwear in which a one-piece 
molded foam base section formed the top of the shoe (the upper) and the 
sole. A strap also made of foam was attached to the foot opening of the 
upper, such that the strap could provide support to the Achilles 
portion of the wearer's foot. The strap was attached via connectors 
that allowed it to be in contact with the base section, and to pivot 
relative to the base section. Because both the base portion and the 
strap were made of foam, friction between the strap and the base 
section allowed the strap to maintain its position after pivoting. In 
other words, the foam strap did not fall under the force of gravity to 
a position adjacent to the heel of the base section.
    The International Trade Commission (ITC) determined that the claims 
were obvious over the combination of two pieces of prior art. The first 
was the Aqua Clog, which was a shoe that corresponded to the base 
section of the footwear of the `858 patent. The second was the Aguerre 
patent, which taught heel straps made of elastic or another flexible 
material. In the ITC's view, the claimed invention was obvious because 
the prior art Aqua Clog differed from the claimed invention only as to 
the presence of the strap, and a suitable strap was taught by Aguerre.
    The Federal Circuit disagreed. The Federal Circuit stated that the 
prior art did not teach foam heel straps, or that a foam heel strap 
should be placed in contact with a foam base. The Federal Circuit 
pointed out that the prior art actually counseled against using foam as 
a material for the heel strap of a shoe.

    The record shows that the prior art would actually discourage 
and teach away from the use of foam straps. An ordinary artisan in 
this field would not add a foam strap to the foam Aqua Clog because 
foam was likely to stretch and deform, in addition to causing 
discomfort for a wearer. The prior art depicts foam as unsuitable 
for straps.

Id. at 1309.
    The Federal Circuit continued, stating that even if--contrary to 
fact--the claimed invention had been a combination of elements that 
were known in the prior art, the claims still would have been 
nonobvious. There was testimony in the record that the loose fit of the 
heel strap made the shoe more comfortable for the wearer than prior art 
shoes in which the heel strap was constantly in contact with the 
wearer's foot. In the claimed footwear, the foam heel strap contacted 
the wearer's foot only when needed to help reposition the foot properly 
in the shoe, thus reducing wearer discomfort that could arise from 
constant contact. This desirable feature was a result of the friction 
between the base section and the strap that kept the strap in place 
behind the Achilles portion of the wearer's foot. The Federal Circuit 
pointed out that this combination ``yielded more than predictable 
results.'' Id. at 1310. Aguerre had taught that friction between the 
base section and the strap was a problem rather than an advantage, and 
had suggested the use of nylon washers to reduce friction. Thus the 
Federal Circuit stated that even if all elements of the claimed 
invention had been taught by the prior art, the claims would not have 
been obvious because the combination yielded more than predictable 
results.
    The Federal Circuit's discussion in Crocs serves as a reminder to 
Office personnel that merely pointing to the presence of all claim 
elements in the prior art is not a complete statement of a rejection 
for obviousness. In accordance with MPEP Sec.  2143 A(3), a proper 
rejection based on the rationale that the claimed invention is a 
combination of prior art elements also includes a finding that results 
flowing from the combination would have been predictable to a person of 
ordinary skill in the art. MPEP Sec.  2143 A(3). If results would not 
have been predictable, Office personnel should not enter an obviousness 
rejection using the combination of prior art elements rationale, and 
should withdraw such a rejection if it has been made.
    Example 4.3. Sundance, Inc. v. DeMonte Fabricating Ltd., 550 F.3d 
1356 (Fed. Cir. 2008). Teaching point: A claimed invention is likely to 
be obvious if it is a combination of known prior art elements that 
would reasonably have been expected to maintain their respective 
properties or functions after they have been combined.
    Sundance involved a segmented and mechanized cover for trucks, 
swimming pools, or other structures. The claim was found to be obvious 
over the prior art applied.
    A first prior art reference taught that a reason for making a 
segmented cover was ease of repair, in that a single damaged segment 
could be readily removed and replaced when necessary. A second prior 
art reference taught the advantages of a mechanized cover for ease of 
opening. The Federal Circuit noted that the segmentation aspect of the 
first reference and the mechanization function of the second perform in 
the same way after combination as they had before. The Federal Circuit 
further observed that a person of ordinary skill in the art would have 
expected that adding replaceable segments as taught by the first 
reference to the mechanized cover of the other would result in a cover 
that maintained the advantageous properties of both of the prior art 
covers.
    Thus, the Sundance case points out that a hallmark of a proper 
obviousness rejection based on combining known prior art elements is 
that one of ordinary skill in the art would reasonably have expected 
the elements to maintain their respective properties or functions after 
they have been combined.

[[Page 53648]]

    Example 4.4. Ecolab, Inc. v. FMC Corp., 569 F.3d 1335 (Fed Cir. 
2009). Teaching point: A combination of known elements would have been 
prima facie obvious if an ordinarily skilled artisan would have 
recognized an apparent reason to combine those elements and would have 
known how to do so.
    In the case of Ecolab, Inc. v. FMC Corp., an ``apparent reason to 
combine'' in conjunction with the technical ability to optimize led to 
the conclusion that the claimed invention would have been obvious.
    The invention in question was a method of treating meat to reduce 
the incidence of pathogens, by spraying the meat with an antibacterial 
solution under specified conditions. The parties did not dispute that a 
single prior art reference had taught all of the elements of the 
claimed invention, except for the pressure limitation of ``at least 50 
psi.''
    FMC had argued at the district court that the claimed invention 
would have been obvious in view of the first prior art reference 
mentioned above in view of a second reference that had taught the 
advantages of spray-treating at pressures of 20 to 150 psi when 
treating meat with a different antibacterial agent. The district court 
did not find FMC's argument to be convincing, and denied the motion for 
judgment as a matter of law that the claim was obvious.
    Disagreeing with the district court, the Federal Circuit stated 
that ``there was an apparent reason to combine these known elements--
namely to increase contact between the [antibacterial solution] and the 
bacteria on the meat surface and to use the pressure to wash additional 
bacteria off the meat surface.'' Id. at 1350. The Federal Circuit 
explained that because the second reference had taught ``using high 
pressure to improve the effectiveness of an antimicrobial solution when 
sprayed onto meat, and because an ordinarily skilled artisan would have 
recognized the reasons for applying [the claimed antibacterial 
solution] using high pressure and would have known how to do so, 
Ecolab's claims combining high pressure with other limitations 
disclosed in FMC's patent are invalid as obvious.'' Id.
    When considering the question of obviousness, Office personnel 
should keep in mind the capabilities of a person of ordinary skill. In 
Ecolab, the Federal Circuit stated:

    Ecolab's expert admitted that one skilled in the art would know 
how to adjust application parameters to determine the optimum 
parameters for a particular solution. The question then is whether 
it would have been obvious to combine the high pressure parameter 
disclosed in the Bender patent with the PAA methods disclosed in 
FMC's `676 patent. The answer is yes.

Id. If optimization of the application parameters had not been within 
the level of ordinary skill in the art, the outcome of the Ecolab case 
may well have been different.
    Example 4.5. Wyers v. Master Lock Co., No. 2009-1412, --F.3d--, 
2010 WL 2901839 (Fed. Cir. July 22, 2010). Teaching point: The scope of 
analogous art is to be construed broadly and includes references that 
are reasonably pertinent to the problem that the inventor was trying to 
solve. Common sense may be used to support a legal conclusion of 
obviousness so long as it is explained with sufficient reasoning.
    In the case of Wyers v. Master Lock Co., the Federal Circuit held 
that the claimed barbell-shaped hitch pin locks used to secure trailers 
to vehicles were obvious.
    The court discussed two different sets of claims in Wyers, both 
drawn to improvements over the prior art hitch pin locks. The first 
improvement was a removable sleeve that could be placed over the shank 
of the hitch pin lock so that the same lock could be used with towing 
apertures of varying sizes. The second improvement was an external flat 
flange seal adapted to protect the internal lock mechanism from 
contaminants. Wyers had admitted that each of several prior art 
references taught every element of the claimed inventions except for 
the removable sleeve and the external covering. Master Lock had argued 
that these references, in combination with additional references 
teaching the missing elements, would have rendered the claims obvious.
    The court first addressed the question of whether the additional 
references relied on by Master Lock were analogous prior art. As to the 
reference teaching the sleeve improvement, the court concluded that it 
dealt specifically with using a vehicle to tow a trailer, and was 
therefore in the same field of endeavor as Wyers' sleeve improvement. 
The reference teaching the sealing improvement dealt with a padlock 
rather than a lock for a tow hitch. The court noted that Wyers' 
specification had characterized the claimed invention as being in the 
field of locking devices, thus at least suggesting that the sealed 
padlock reference was in the same field of endeavor. However, the court 
also observed that even if sealed padlocks were not in the same field 
of endeavor, they were nevertheless reasonably pertinent to the problem 
of avoiding contamination of a locking mechanism for tow hitches. The 
court explained that the Supreme Court's decision in KSR ``directs [it] 
to construe the scope of analogous art broadly.'' Wyers, slip. op. at 
12. For these reasons, the court found that Master Lock's asserted 
references were analogous prior art, and therefore relevant to the 
obviousness inquiry.
    The court then turned to the question of whether there would have 
been adequate motivation to combine the prior art elements as had been 
urged by Master Lock. The court recalled the Graham inquiries, and also 
emphasized the ``expansive and flexible'' post-KSR approach to 
obviousness that must not ``deny factfinders recourse to common 
sense.'' Wyers, slip op. at 13 (quoting KSR, 550 U.S. at 415 and 421). 
The court stated:

    KSR and our later cases establish that the legal determination 
of obviousness may include recourse to logic, judgment, and common 
sense, in lieu of expert testimony * * *.
    Thus, in appropriate cases, the ultimate inference as to the 
existence of a motivation to combine references may boil down to a 
question of ``common sense,'' appropriate for resolution on summary 
judgment or JMOL.

Id. at 15 (citing Perfect Web Techs., Inc. v. InfoUSA, Inc., 587 F.3d 
1324, 1329 (Fed. Cir. 2009); Ball Aerosol, 555 F.3d at 993).
    After reviewing these principles, the court proceeded to explain 
why adequate motivation to combine had been established in this case. 
With regard to the sleeve improvement, it pointed out that the need for 
different sizes of hitch pins was well known in the art, and that this 
was a known source of inconvenience and expense for users. The court 
also mentioned the marketplace aspect of the issue, noting that space 
on store shelves was at a premium, and that removable sleeves addressed 
this economic concern. As to the sealing improvement, the court pointed 
out that both internal and external seals were well-known means to 
protect locks from contaminants. The court concluded that the 
constituent elements were being employed in accordance with their 
recognized functions, and would have predictably retained their 
respective functions when combined as suggested by Master Lock. The 
court cited In re O'Farrell, 853 F.2d 894, 904 (Fed. Cir. 1988) for the 
proposition that a reasonable expectation of success is a requirement 
for a proper determination of obviousness.
    Office personnel should note that although the Federal Circuit 
invoked the idea of common sense in support of a conclusion of 
obviousness, it did not end its explanation there. Rather, the

[[Page 53649]]

court explained why a person of ordinary skill in the art at the time 
of the invention, in view of the facts relevant to the case, would have 
found the claimed inventions to have been obvious. As stated in the 
MPEP:

    The key to supporting any rejection under 35 U.S.C. 103 is the 
clear articulation of the reason(s) why the claimed invention would 
have been obvious. The Supreme Court in KSR noted that the analysis 
supporting a rejection under 35 U.S.C. 103 should be made explicit. 
The Court quoting In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 
1336 (Fed. Cir. 2006), stated that ``[R]ejections on obviousness 
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.''

MPEP Sec.  2141 III. Office personnel should continue to provide a 
reasoned explanation for every obviousness rejection.
    Example 4.6. DePuy Spine, Inc. v. Medtronic Sofamor Danek, Inc., 
567 F.3d 1314 (Fed. Cir. 2009). Teaching point: Predictability as 
discussed in KSR encompasses the expectation that prior art elements 
are capable of being combined, as well as the expectation that the 
combination would have worked for its intended purpose. An inference 
that a claimed combination would not have been obvious is especially 
strong where the prior art's teachings undermine the very reason being 
proffered as to why a person of ordinary skill would have combined the 
known elements.
    The claim in DePuy Spine was directed to a polyaxial pedicle screw 
used in spinal surgeries that included a compression member for 
pressing a screw head against a receiver member. A prior art reference 
(Puno) disclosed all of the elements of the claim except for the 
compression member. Instead, the screw head in Puno was separated from 
the receiver member to achieve a shock absorber effect, allowing some 
motion between receiver member and the vertebrae. The missing 
compression member was readily found in another prior art reference 
(Anderson), which disclosed an external fracture immobilization splint 
for immobilizing long bones with a swivel clamp capable of polyaxial 
movement until rigidly secured by a compression member. It was asserted 
during trial that a person of ordinary skill would have recognized that 
the addition of Anderson's compression member to Puno's device would 
have achieved a rigidly locked polyaxial pedicle screw covered by the 
claim.
    In conducting its analysis, the Federal Circuit noted that the 
``predictable result'' discussed in KSR refers not only to the 
expectation that prior art elements are capable of being physically 
combined, but also that the combination would have worked for its 
intended purpose. In this case, it was successfully argued that Puno 
``teaches away'' from a rigid screw because Puno warned that rigidity 
increases the likelihood that the screw will fail within the human 
body, rendering the device inoperative for its intended purpose. In 
fact, the reference did not merely express a general preference for 
pedicle screws having a ``shock absorber'' effect, but rather expressed 
concern for failure and stated that the shock absorber feature 
``decrease[s] the chance of failure of the screw of the bone-screw 
interface'' because ``it prevent[s] direct transfer of load from the 
rod to the bone-screw interface.'' Thus, the alleged reason to combine 
the prior art elements of Puno and Anderson--increasing the rigidity of 
the screw--ran contrary to the prior art that taught that increasing 
rigidity would result in a greater likelihood of failure. In view of 
this teaching and the backdrop of collective teachings of the prior 
art, the Federal Circuit determined that Puno teaches away from the 
proposed combination such that a person of ordinary skill would have 
been deterred from combining the references as proposed. Secondary 
considerations evaluated by the Federal Circuit relating to failure by 
others and copying also supported the view that the combination would 
not have been obvious at the time of the invention.
    B. Substituting One Known Element for Another. As explained in the 
2007 KSR Guidelines, the substitution rationale applies when the 
claimed invention can be viewed as resulting from substituting a known 
element for an element of a prior art invention. The rationale applies 
when one of ordinary skill in the art would have been technologically 
capable of making the substitution, and the result obtained would have 
been predictable. See MPEP Sec.  2143(B).
    Example 4.7. In re ICON Health & Fitness, Inc., 496 F.3d 1374 (Fed. 
Cir. 2007). Teaching point: When determining whether a reference in a 
different field of endeavor may be used to support a case of 
obviousness (i.e., is analogous), it is necessary to consider the 
problem to be solved.
    The claimed invention in ICON was directed to a treadmill with a 
folding tread base that swivels into an upright storage position, 
including a gas spring connected between the tread base and the upright 
structure to assist in stably retaining the tread base in the storage 
position. On reexamination, the examiner rejected the claims as obvious 
based on a combination of references including an advertisement 
(Damark) for a folding treadmill demonstrating all of the claim 
elements other than the gas spring, and a patent (Teague) with a gas 
spring. Teague was directed to a bed that folds into a cabinet using a 
novel dual-action spring that reverses force as the mechanism passes a 
neutral position, rather than a single-action spring that would provide 
a force pushing the bed closed at all times. The dual-action spring 
reduced the force required to open the bed from the closed position, 
while reducing the force required to lift the bed from the open 
position.
    The Federal Circuit addressed the propriety of making the 
combination since Teague comes from a different field than the 
application. Teague was found to be reasonably pertinent to the problem 
addressed in the application because the folding mechanism did not 
require any particular focus on treadmills, but rather generally 
addressed problems of supporting the weight of such a mechanism and 
providing a stable resting position.
    Other evidence was considered concerning whether one skilled in the 
art would have been led to combine the teachings of Damark and Teague. 
Appellant argued that Teague teaches away from the invention because it 
directs one skilled in the art not to use single-action springs and 
does not satisfy the claim limitations as the dual-action springs would 
render the invention inoperable. The Federal Circuit considered the 
arguments and found that while Teague at most teaches away from using 
single-action springs to decrease the opening force, it actually 
instructed that single-action springs provide the result desired by the 
inventors, which was to increase the opening force provided by gravity. 
As to inoperability, the claims were not limited to single-action 
springs and were so broad as to encompass anything that assists in 
stably retaining the tread base, which is the function that Teague 
accomplished. Additionally, the fact that the counterweight mechanism 
from Teague used a large spring, which appellant argued would overpower 
the treadmill mechanism, ignores the modifications that one skilled in 
the art would make to a device borrowed from the prior art. One skilled 
in the art would size the components from Teague appropriately for the 
application.
    ICON is another useful example for understanding the scope of 
analogous art. The art applied concerned retaining mechanisms for 
folding beds, not treadmills. When determining whether a

[[Page 53650]]

reference may properly be applied to an invention in a different field 
of endeavor, it is necessary to consider the problem to be solved. It 
is certainly possible that a reference may be drawn in such a way that 
its usefulness as a teaching is narrowly restricted. However, in ICON, 
the ``treadmill'' concept was too narrow a lens through which to view 
the art in light of the prior art teachings concerning the problem to 
be solved. The Teague reference was analogous art because ``Teague and 
the current application both address the need to stably retain a 
folding mechanism,'' id. at 1378, and because ``nothing about ICON's 
folding mechanism requires any particular focus on treadmills,'' id. at 
1380.
    ICON is also informative as to the relationship between the problem 
to be solved and existence of a reason to combine. ``Indeed, while 
perhaps not dispositive of the issue, the finding that Teague, by 
addressing a similar problem, provides analogous art to ICON's 
application goes a long way towards demonstrating a reason to combine 
the two references. Because ICON's broad claims read on embodiments 
addressing that problem as described by Teague, the prior art here 
indicates a reason to incorporate its teachings.'' Id. at 1380-81.
    The Federal Circuit's discussion in ICON also makes clear that if 
the reference does not teach that a combination is undesirable, then it 
cannot be said to teach away. An assessment of whether a combination 
would render the device inoperable must not ``ignore the modifications 
that one skilled in the art would make to a device borrowed from the 
prior art.'' Id. at 1382.
    Example 4.8. Agrizap, Inc. v. Woodstream Corp., 520 F.3d 1337 (Fed. 
Cir. 2008). Teaching point: Analogous art is not limited to references 
in the field of endeavor of the invention, but also includes references 
that would have been recognized by those of ordinary skill in the art 
as useful for applicant's purpose.
    Agrizap involved a stationary pest control device for electrocution 
of pests such as rats and gophers, in which the device is set in an 
area where the pest is likely to encounter it. The only difference 
between the claimed device and the prior art stationary pest control 
device was that the claimed device employed a resistive electrical 
switch, while the prior art device used a mechanical pressure switch. A 
resistive electrical switch was taught in two prior art patents, in the 
contexts of a hand-held pest control device and a cattle prod.
    In determining that the claimed invention was obvious, the Federal 
Circuit noted that ``[t]he asserted claims simply substitute a 
resistive electrical switch for the mechanical pressure switch'' 
employed in the prior art device. Id. at 1344. In this case, the prior 
art concerning the hand-held devices revealed that the function of the 
substituted resistive electrical switch was well known and predictable, 
and that it could be used in a pest control device. According to the 
Federal Circuit, the references that taught the hand-held devices 
showed that ``the use of an animal body as a resistive switch to 
complete a circuit for the generation of an electric charge was already 
well known in the prior art.'' Id. Finally, the Federal Circuit noted 
that the problem solved by using the resistive electrical switch in the 
prior art hand-held devices--malfunction of mechanical switches due to 
dirt and dampness--also pertained to the prior art stationary pest 
control device.
    The Federal Circuit recognized Agrizap as ``a textbook case of when 
the asserted claims involve a combination of familiar elements 
according to known methods that does no more than yield predictable 
results.'' Id. Agrizap exemplifies a strong case of obviousness based 
on simple substitution that was not overcome by the objective evidence 
of nonobviousness offered. It also demonstrates that analogous art is 
not limited to the field of applicant's endeavor, in that one of the 
references that used an animal body as a resistive switch to complete a 
circuit for the generation of an electric charge was not in the field 
of pest control.
    Example 4.9. Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318 
(Fed. Cir. 2008). Teaching point: Because Internet and Web browser 
technologies had become commonplace for communicating and displaying 
information, it would have been obvious to adapt existing processes to 
incorporate them for those functions.
    The invention at issue in Muniauction was a method for auctioning 
municipal bonds over the Internet. A municipality could offer a package 
of bond instruments of varying principal amounts and maturity dates, 
and an interested buyer would then submit a bid comprising a price and 
interest rate for each maturity date. It was also possible for the 
interested buyer to bid on a portion of the offering. The claimed 
invention considered all of the noted parameters to determine the best 
bid. It operated on conventional Web browsers and allowed participants 
to monitor the course of the auction.
    The only difference between the prior art bidding system and the 
claimed invention was the use of a conventional Web browser. At trial, 
the district court had determined that Muniauction's claims were not 
obvious. Thomson argued that the claimed invention amounted to 
incorporating a Web browser into a prior art auction system, and was 
therefore obvious in light of KSR. Muniauction rebutted the argument by 
offering evidence of skepticism by experts, copying, praise, and 
commercial success. Although the district court found the evidence to 
be persuasive of nonobviousness, the Federal Circuit disagreed. It 
noted that a nexus between the claimed invention and the proffered 
evidence was lacking because the evidence was not coextensive with the 
claims at issue. For this reason, the Federal Circuit determined that 
Muniauction's evidence of secondary considerations was not entitled to 
substantial weight.
    The Federal Circuit analogized this case to Leapfrog Enterprises, 
Inc. v. Fisher-Price, Inc., 485 F.3d 1157 (Fed. Cir. 2007), cited in 
the 2007 KSR Guidelines. The Leapfrog case involved a determination of 
obviousness based on application of modern electronics to a prior art 
mechanical children's learning device. In Leapfrog, the court had noted 
that market pressures would have prompted a person of ordinary skill to 
use modern electronics in the prior art device. Similarly in 
Muniauction, market pressures would have prompted a person of ordinary 
skill to use a conventional Web browser in a method of auctioning 
municipal bonds.
    Example 4.10. Aventis Pharma Deutschland v. Lupin Ltd., 499 F.3d 
1293 (Fed. Cir. 2007). Teaching point: A chemical compound would have 
been obvious over a mixture containing that compound as well as other 
compounds where it was known or the skilled artisan had reason to 
believe that some desirable property of the mixture was derived in 
whole or in part from the claimed compound, and separating the claimed 
compound from the mixture was routine in the art.
    In Aventis, the claims were drawn to the 5(S) stereoisomer of the 
blood pressure drug ramipril in stereochemically pure form, and to 
compositions and methods requiring 5(S) ramipril. The 5(S) stereoisomer 
is one in which all five stereocenters in the ramipril molecule are in 
the S rather than the R configuration. A mixture of various 
stereoisomers including 5(S) ramipril had been taught by the prior art. 
The question before the court was whether the purified single 
stereoisomer

[[Page 53651]]

would have been obvious over the known mixture of stereoisomers.
    The record showed that the presence of multiple S stereocenters in 
drugs similar to ramipril was known to be associated with enhanced 
therapeutic efficacy. For example, when all of the stereocenters were 
in the S form in the related drug enalapril (SSS enalapril) as compared 
with only two stereocenters in the S form (SSR enalapril), the 
therapeutic potency was 700 times as great. There was also evidence to 
indicate that conventional methods could be used to separate the 
various stereoisomers of ramipril.
    The district court saw the issue as a close case, because, in its 
view, there was no clear motivation in the prior art to isolate 5(S) 
ramipril. However, the Federal Circuit disagreed, and found that the 
claims would have been obvious. The Federal Circuit cautioned that 
requiring such a clearly stated motivation in the prior art to isolate 
5(S) ramipril ran counter to the Supreme Court's decision in KSR. The 
court stated:

    Requiring an explicit teaching to purify the 5(S) stereoisomer 
from a mixture in which it is the active ingredient is precisely the 
sort of rigid application of the TSM test that was criticized in 
KSR.

    Id. at 1301. The Aventis court also relied on the settled principle 
that in chemical cases, structural similarity can provide the necessary 
reason to modify prior art teachings. The Federal Circuit also 
addressed the kind of teaching that would be sufficient in the absence 
of an explicitly stated prior art-based motivation, explaining that an 
expectation of similar properties in light of the prior art can be 
sufficient, even without an explicit teaching that the compound will 
have a particular utility.
    In the chemical arts, the cases involving so-called ``lead 
compounds'' form an important subgroup of the obviousness cases that 
are based on substitution. The Federal Circuit has had a number of 
opportunities since the KSR decision to discuss the circumstances under 
which it would have been obvious to modify a known compound to arrive 
at a claimed compound. The following cases explore the selection of a 
lead compound, the need to provide a reason for any proposed 
modification, and the predictability of the result.
    Example 4.11. Eisai Co. Ltd. v. Dr. Reddy's Labs., Ltd., 533 F.3d 
1353 (Fed. Cir. 2008). Teaching point: A claimed compound would not 
have been obvious where there was no reason to modify the closest prior 
art lead compound to obtain the claimed compound and the prior art 
taught that modifying the lead compound would destroy its advantageous 
property. Any known compound may serve as a lead compound when there is 
some reason for starting with that lead compound and modifying it to 
obtain the claimed compound.
    Eisai concerns the pharmaceutical compound rabeprazole. Rabeprazole 
is a proton pump inhibitor for treating stomach ulcers and related 
disorders. The Federal Circuit affirmed the district court's summary 
judgment of nonobviousness, stating that no reason had been advanced to 
modify the prior art compound in a way that would destroy an 
advantageous property.
    Co-defendant Teva based its obviousness argument on the structural 
similarity between rabeprazole and lansoprazole. The compounds were 
recognized as sharing a common core, and the Federal Circuit 
characterized lansoprazole as a ``lead compound.'' The prior art 
compound lansoprazole was useful for the same indications as 
rabeprazole, and differed from rabeprazole only in that lansoprazole 
has a trifluoroethoxy substituent at the 4-position of the pyridine 
ring, while rabeprazole has a methoxypropoxy substituent. The trifluoro 
substituent of lansoprazole was known to be a beneficial feature 
because it conferred lipophilicity to the compound. The ability of a 
person of ordinary skill to carry out the modification to introduce the 
methoxypropoxy substituent, and the predictability of the result were 
not addressed.
    Despite the significant similarity between the structures, the 
Federal Circuit did not find any sufficient reason to modify the lead 
compound. According to the Federal Circuit:

    Obviousness based on structural similarity thus can be proved by 
identification of some motivation that would have led one of 
ordinary skill in the art to select and then modify a known compound 
(i.e. a lead compound) in a particular way to achieve the claimed 
compound. * * * In keeping with the flexible nature of the 
obviousness inquiry, KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 
127 S.Ct. 1727, 1739, 167 L.Ed.2d 705 (2007), the requisite 
motivation can come from any number of sources and need not 
necessarily be explicit in the art. See Aventis Pharma Deutschland 
GmbH v. Lupin, Ltd., 499 F.3d 1293, 1301 (Fed. Cir. 2007). Rather 
``it is sufficient to show that the claimed and prior art compounds 
possess a `sufficiently close relationship * * * to create an 
expectation,' in light of the totality of the prior art, that the 
new compound will have `similar properties' to the old.'' Id. 
(quoting Dillon, 919 F.2d at 692).

    Eisai, 533 F.3d at 1357. The prior art taught that introducing a 
fluorinated substituent was known to increase lipophilicity, so a 
skilled artisan would have expected that replacing the trifluoroethoxy 
substituent with a methoxypropoxy substituent would have reduced the 
lipophilicity of the compound. Thus, the prior art created the 
expectation that rabeprazole would be less useful than lansoprazole as 
a drug for treating stomach ulcers and related disorders because the 
proposed modification would have destroyed an advantageous property of 
the prior art compound. The compound was not obvious as argued by Teva 
because, upon consideration of all of the facts of the case, a person 
of ordinary skill in the art at the time of the invention would not 
have had a reason to modify lansoprazole so as to form rabeprazole.
    Office personnel are cautioned that the term ``lead compound'' in a 
particular opinion can have a contextual meaning that may vary from the 
way a pharmaceutical chemist might use the term. In the field of 
pharmaceutical chemistry, the term ``lead compound'' has been defined 
variously as ``a chemical compound that has pharmacological or 
biological activity and whose chemical structure is used as a starting 
point for chemical modifications in order to improve potency, 
selectivity, or pharmacokinetic parameters;'' ``[a] compound that 
exhibits pharmacological properties which suggest its development;'' 
and ``a potential drug being tested for safety and efficacy.'' See, 
e.g.,https://en.wikipedia.org/wiki/Lead_compound, accessed January 13, 
2010; https://www.combichemistry.com/glossary_k.html, accessed January 
13, 2010; and https://www.buildingbiotechnology.com/glossary4.php, 
accessed January 13, 2010.
    The Federal Circuit in Eisai makes it clear that from the 
perspective of the law of obviousness, any known compound might 
possibly serve as a lead compound: ``Obviousness based on structural 
similarity thus can be proved by identification of some motivation that 
would have led one of ordinary skill in the art to select and then 
modify a known compound (i.e. a lead compound) in a particular way to 
achieve the claimed compound.'' Eisai, 533 F.3d at 1357. Thus, Office 
personnel should recognize that a proper obviousness rejection of a 
claimed compound that is useful as a drug might be made beginning with 
an inactive compound, if, for example, the reasons for modifying a 
prior art compound to arrive at the claimed compound have nothing to do 
with pharmaceutical activity. The inactive compound would not be 
considered to be a lead

[[Page 53652]]

compound by pharmaceutical chemists, but could potentially be used as 
such when considering obviousness. Office personnel might also base an 
obviousness rejection on a known compound that pharmaceutical chemists 
would not select as a lead compound due to expense, handling issues, or 
other business considerations. However, there must be some reason for 
starting with that lead compound other than the mere fact that the 
``lead compound'' merely exists. See Altana Pharma AG v. Teva 
Pharmaceuticals USA, Inc., 566 F.3d 999, 1007 (Fed. Cir. 2009) (holding 
that there must be some reason ``to select and modify a known 
compound''); Ortho-McNeil Pharmaceutical, Inc. v. Mylan Labs, Inc., 520 
F.3d 1358, 1364 (Fed. Cir. 2008).
    Example 4.12. Procter & Gamble Co. v. Teva Pharmaceuticals USA, 
Inc., 566 F.3d 989 (Fed. Cir. 2009). Teaching point: It is not 
necessary to select a single compound as a ``lead compound'' in order 
to support an obviousness rejection. However, where there was reason to 
select and modify the lead compound to obtain the claimed compound, but 
no reasonable expectation of success, the claimed compound would not 
have been obvious.
    A chemical compound was also found to be nonobvious in Procter & 
Gamble. The compound at issue was risedronate--the active ingredient of 
Procter & Gamble's osteoporosis drug Actonel[reg]. Risedronate is an 
example of a bisphosphonate, which is a class of compounds known to 
inhibit bone resorption.
    When Procter & Gamble sued Teva for infringement, Teva defended by 
arguing invalidity for obviousness over one of Procter & Gamble's 
earlier patents. The prior art patent did not teach risedronate, but 
instead taught thirty-six other similar compounds including 2-pyr EHDP 
that were potentially useful with regard to osteoporosis. Teva argued 
obviousness on the basis of structural similarity to 2-pyr EHDP, which 
is a positional isomer of risedronate.
    The district court found no reason to select 2-pyr EHDP as a lead 
compound in light of the unpredictable nature of the art, and no reason 
to modify it so as to obtain risedronate. In addition, there were 
unexpected results as t