Lessons from Purdue: Patent Practitioner Tips for Avoiding Inequitable Conduct Claims

'It has now been surprisingly discovered ' '

With these words in Purdue Pharma's U.S. Patent Nos. 5,656,295, 5,508,042 and 5,549,912, Endo Pharmaceuticals asserted a basis to challenge the enforceability of Purdue's controlled-release oxycodone formulations due to inequitable conduct. Purdue Pharma L.P. v. Endo Pharms., Inc., 438 F.3d 1123 (Fed. Cir. 2006).

Inequitable conduct is a showing that applicants for a patent have failed in their duty to prosecute their patent application before the U.S. Patent and Trademark Office ('PTO') with candor and in good faith. 37 C.F.R. '1.56(a). A breach of this duty includes affirmative misrepresentations of a material fact (or submission of false material information) or failure to disclose material information, coupled with an intent to deceive or mislead the PTO. Molins PLC v. Textron, Inc., 48 F.3d 1172, 1178 (Fed. Cir. 1995). A showing of inequitable conduct as to a single claim or a single applicant can render the entire patent unenforceable. See, e.g., Hewlett-Packard Co. v. Bausch & Lomb, Inc., 882 F.2d 1556 (Fed. Cir. 1989) (inequitable conduct as to one claim extends to all others) and see, e.g., Syntex (U.S.A) L.L.C. v. Apotex, Inc., 407 F.3d 1371 (Fed. Cir. 2005) (inequitable conduct by improperly named inventors applied to unnamed, actual inventors).

At trial, while Endo's generic formulation was determined to infringe Purdue's patented product, Purdue's repeated statements to the PTO that it had discovered a formulation with an improved dosing profile were held to be an intentional failure to disclose material facts. Particularly, Purdue's claim to a 'discovery' was based on 'insight without scientific proof.'

Purdue appealed and lost again, at which point it petitioned for a rehearing. In a rare reversal, the same three-person panel of judges on the Court of Appeals for the Federal Circuit ('CAFC') came to a new conclusion as to the degree of materiality and the allowable inference of intent as a result. The court reaffirmed that Purdue failed to disclose what was behind its 'surprising discovery' and that as such the threshold of materiality for inequitable conduct was met. However, the panel also noted that it was not highly material because Purdue 'did not expressly misrepresent to the PTO' that it had obtained experimental results. Noteworthy was Purdue's attempt to argue that even if material, its omissions were not relevant since the examiner could have allowed the claims based on other arguments made to distinguish the claims over the prior art. In rejecting a 'but-for' test, the court reiterated its stance that materiality is wide in scope and extends beyond matters pertaining to patent issuance. The court also emphasized that while materiality is a factor in its determination of ine-quitable conduct, it cannot be the only factor since intent is a separate and necessary determination in which a threshold showing must also be made. There must also necessarily be culpability, and such culpability must arise from more than inadvertence, carelessness, or gross negligence. Kingsdown Medical Consultants v. Hollister, Inc., 863 F.2d 867 (Fed. Cir. 1988) (en banc) (holding that 'gross negligence does not of itself justify an inference of intent to deceive; the involved conduct, viewed in light of all the evidence, including evidence indicative of good faith, must indicate sufficient culpability to require a finding of intent to deceive.')

The trial court had found that in internal documents Purdue revealed its concerns at meeting the higher evidentiary standards before the FDA and utilized these concerns as indicative of intent. The appellate court clarified that since FDA evidentiary standards are by their nature higher than those before the PTO, these concerns were only marginally relevant as to Purdue's alleged intent to deceive the PTO. Further, the court reaffirmed that evidence of Purdue's good faith was improperly discounted at trial.

Purdue and Endo have now settled the patent infringement suit (which was announced Aug. 28, 2006). According to the agreement, Endo will stop selling infringing versions of its OxyContin by the end of the year. In exchange, Purdue Pharma will not pursue damages against Endo for Endo's past infringement.

As illustrated by this case, a patent practitioner must be aware of the plethora of facts and issues the PTO considers material and therefore disclosable. The consequences of an inequitable conduct charge, if sustained, are dire. It can lead to the total unenforceability of a patent and even related patents. See, e.g., Consolidated Alum. Corp v. Foseco Int'l Ltd., 910 F.2d 804 (Fed. Cir. 1990) (holding that inequitable conduct as to one patent may so permeate the others that all are unenforceable). Indeed, it is a trap for the unwary and has become a frequent counter-charge in infringement cases. The Federal Circuit has stated that 'the habit of charging inequitable conduct in almost every major patent case has become an absolute plague.' Burlington Indus. Inc. v. Dayco Corp., 849 F.2d 1418, 1422 (Fed. Cir. 1988), and that '[i]nequitable conduct is not, or should not be, a magic incantation to be asserted against every patentee.' FMC Corp. v. Manitowoc Co., 835 F.2d 1411, 1415 (Fed. Cir. 1987).

An inequitable conduct charge can also have consequences far beyond unenforceability of a patent; it may lead to devastating professional sanctions as well. This article provides the patent practitioner with suggestions to potentially avoid these pitfalls.

Practitioner Tips

• Advise inventors of their duty. Inventors should be reminded, at a minimum in a disclaimer included in all communications, to disclose all information material to patentability and that such a duty continues throughout prosecution of their patent. An inventor should be told to consider the scope of materiality as broadly as possible.
• Be careful with examples and descriptions in the specification. Avoid misidentification or misinterpretation of any prior art in any background sections, as well as inaccurate or unjustified technical statements in patent specifications. Draft examples to avoid any misleading inferences; eg, 'paper examples' should be drafted in the present tense to avoid giving the impression that they were actually carried out. See Hoffmann-La Roche, Inc. v. Promega, 323 F.3d 1354, 1363 (Fed. Cir. 2003).
• Be careful when drafting and submitting declarations. When submitting test results, it is crucial that a sound scientific basis exists for excluding certain experimental data. See, e.g., Glaxo Inc. v. Novopharm Ltd., 52 F.3d 1043 (Fed. Cir. 1995). In addition, a practitioner must make sure that experts or other third parties who submit a declaration reveal any conflicts of interest. See, e.g., Ferring B.V. v. Barr Labs., Inc, 437 F.3d 1181 (Fed. Cir. 2006); Refac International, Ltd. v. Lotus Devel-opment Corp., 81 F.3d 1576 (Fed. Cir. 1996). A practitioner should also ascertain whether the declarant has made statements elsewhere that potentially contradict the information in the document to be submitted to the PTO. See, e.g., Pharmacia Corp. v. Par Pharma-ceuticals, Inc., 417 F.3d 1369 (Fed. Cir. 2005). If so, then the basis for such inconsistency should be investigated and disclosed.
• Monitor related foreign applications. Actions of foreign attorneys will be imputed to the U.S. practitioner; that is, the duty of disclosure applies equally to foreign practitioners who represent claims in the U.S. PTO through local U.S. firms. See M.P.E.P. '2001.06(a). U.S. pa-tents have been declared unenforceable because the foreign attorney did not disclose to the PTO prior art that was cited by a foreign patent office during prosecution of the corresponding foreign application. See Gemveto Jewelry Co. v. Lambert Bros., Inc., 542 F. Supp. 933, 943 (S.D.N.Y. 1982). Consequently, a practitioner must make sure to disclose to the PTO all relevant information stemming from prosecution of a related, foreign application.
• Consider all sources of material information. A fundamental and often ignored guideline is that material information encompasses much more than prior art under 35 U.S.C. '102. Rule 56 emphasizes that materiality embraces 'all information known … to be material to patentability,' including, but not limited to, information on small entity status, inventorship, enablement, written description, best mode, and priority. See M.P.E.P. '2001.04. See also Bristol-Myers Squibb Co. v. Rhone-Poulenc Rorer, Inc., 326 F.3d 1226, 1241 (Fed. Cir. 2003). A practitioner should therefore have the big patentability picture in mind when carrying out a materiality analysis. To base such an analysis only on prior art under '102 is to potentially invite a later charge of inequitable conduct. A practitioner must also remember that the duty of disclosure extends to trade secret, proprietary, and protective order materials that are material and non-cumulative.
• Consider information a reasonable examiner would deem im-portant as to issuance of a patent to be material. The Federal Circuit has utilized a number of tests over the years ranging from a reasonable examiner standard to the more narrow rule embodied in PTO Rule 56. Despite variations on the standard, the court has stated that all standards are applicable 'to the extent that one standard requires a higher showing of materiality; the requisite finding of intent may be lower.' See Digital Control Inc., v. The Charles Mach. Works, 437 F.3d 1309 (Fed. Cir. 2006). The broadest rule should therefore be considered.
• Select references according to their relevance. A practitioner should adopt a generous screening approach that favors inclusion for several reasons. First, the standard for materiality is not whether the applicant personally regards prior art as material; it is whether one of ordinary skill in the art would have so regarded a reference. See, e.g., Argus Chem. Corp. v. Fibre Glass-Evercoat Co., 759 F.2d 10 (Fed. Cir. 1985). An applicant should therefore avoid subjective criteria for selecting references. Second, a reference can be material even though it does not disclose all of the limitations of a claimed invention. See, e.g., Molins PLC v. Textron, Inc., 48 F.3d 1172 (Fed. Cir. 1995). The essential inquiry in determining obviousness, for example, is whether the teachings of a reference, in combination with other prior art, 'would have rendered the claimed invention obvious to one of ordinary skill in the art.' Life Technologies v. Clontech, 224 F.3d 1320 (Fed. Cir. 2000). For these reasons, the practitioner should submit all relevant references, eliminating non-cumulative references that are clearly irrelevant and cumulative references that are marginally relevant. At the same time, a practitioner should not submit so many marginally relevant references as to suggest that a key reference has been buried. See, e.g., Molins PLC, 48 F.3d 1172; Penn Yan Boats, Inc. v. Sea Lark Boats, Inc., 479 F.2d 1328 (5th Cir. 1973). Such a buried reference can infer misconduct; therefore, the PTO advises practitioners to highlight those references that may be of most significance. See M.P.E.P. '2004(13).
• When in doubt, disclose. Applicants are not penalized for submitting references that may ultimately be deemed irrelevant or not material. Indeed, the PTO recognizes the advantage in submitting such information 'because it will result in a strengthened patent and will avoid later questions of materiality and intent to deceive.' M.P.E.P. '2001.04. Similarly, the CAFC has advised that '[I]n close cases, where the materiality of the information is uncertain, disclosure is required.' Brasseller, U.S.A. I, L.P. v. Stryker Sales Corp., 267 F.3d 1370 (Fed. Cir. 2001). Moreover, the PTO points out that its rules facilitate such submissions in at least two ways. First, the burden for most submissions is minimal because the PTO has eliminated the requirement for a 'concise statement of the relevance of each item of information submitted in an information disclosure statement.' Second, submitting such information in an Information Disclosure Statement is not an admission 'that the information cited in the statement is, or is considered to be, material to patentability [under Rule 56].' In fact, references are commonly submitted in an IDS accompanied by such a disclaimer. Where an IDS concerns a patent application that is related to other co-pending U.S. patent applications, then the applicant must bring the co-pending patent applications to the examiner's attention. Under such circumstances, the CAFC has cautioned that 'the examiner of a particular application is not necessarily aware of other applications which are 'material to patentability' of the application in question.^' M.P.E.P. '2001.06(b). For this reason, information in related patent applications has been deemed material. An adverse decision by an examiner in a related but undisclosed case, for example, will meet the threshold for materiality. See, e.g., Dayco Products v. Total Containment, Inc. 329 F.3d 1358 (Fed. Cir. 2003). A failure to cite such co-pending patent applications can support an inference of deceptive intent. See Akron Polymer Container Corp. v. Exxel Container, Inc., 148 F.3d 1380 (Fed. Cir. 1998). Similarly, prior art references cited in a related patent application should be made of record in a subsequent patent application if such prior art references are 'material to patentability' of the subsequent application.

When a cited reference is not in English, the applicant has two options: First, the applicant can provide a statement explaining the document's relevance. Such a statement should be as brief as possible. This will reduce the risk that an adversary will cite the statement against you, arguing that it is incorrect, misleading, deceptive, etc. The second option is to submit an English translation for at least the relevant part of the document. When submitting such a summary, a practitioner must be sure that the untranslated portions do not include material information. Otherwise, the practitioner may face liability for deceptive intent for submitting misleading or incorrect information. See Semiconductor Energy Laboratory Co., Ltd. v. Sam-sung Electronics Co., Ltd., 204 F.3d 1368 (Fed. Cir. 2000).

• Disclose information as needed throughout prosecution. A practitioner must be aware that the duty of candor spans the entire course of patent prosecution, applying to every version of each claim 'until the claim is cancelled or withdrawn from consideration.' Baxter International Inc. v. McGaw Inc., 149 F.3d 1321 (Fed. Cir. 1998). A breach of the duty early in prosecution may therefore lead to unenforceability of all claims that issue from that application as well as from related applications. For this reason, a practitioner should be careful to disclose all known information that is material to the patentability of the original claims ' even if the claims that ultimately issue have a different form.
• Disclose related litigation and PTO administrative proceedings. When the subject matter of a patent application 'is or has been involved in litigation, the existence of such litigation and any material information must be brought promptly to the attention of the PTO.' M.P.E.P. '2001.06(c). Such information may include evidence that bears on prior art, fraud, inequitable conduct, and the violation of duty of disclosure. To meet these requirements, it may not be necessary initially to provide the actual court documents. The M.P.E.P. provides that at a minimum, it is sufficient to 'call to the attention of the Office the litigation, the nature of allegations that bear materially on the original patent, and the nature of the pertinent litigation materials so that the Office can evaluate the need to ask for further materials in the litigation.' Similarly, it is necessary to
  disclose prior PTO Board decisions, as such decisions may bear on the patentability of claims in a current application. See, e.g., Li Second Family Limited Partnership v. Toshiba Corp., 231 F.3d 1373 (Fed. Cir. 2000); Affymetrix, Inc. v. PE Corporation, 2002 WL 1049485 (S.D.N.Y. 2002). Such disclosure may also apply to an interference proceeding that was settled if that settlement did not bar the accused infringer from challenging validity of the disputed patent. See Ad-vanced Cardiovascular Systems, Inc. v. Medtronic, Inc., 265 F.3d 1294 (Fed. Cir. 2001).
• Seek remedial measures. An in-ference of intent cannot be based on materiality alone. Thus, by always conducting actions in good faith, a practitioner may guard against allegations of inequitable conduct. Nevertheless, when the breach is highly material, evidence of good faith will do little to rebut an inference of intent if other factors are present. If one discovers an error during prosecution, arising from some form of possible misconduct, disclose that information promptly. Curing the misconduct is possible if an applicant advises the PTO of the possible fraud and the actual facts and establishes patentability based on the actual facts. Such a cure, however, must be based on clear, unequivocal, and convincing evidence. Rohm & Haas Co. v. Crystal Chem. Co., 722 F.2d 1556 (Fed. Cir. 1983). Such curative measures must therefore include full disclosure to the PTO. Merely amending the claims will not suffice. See, e.g., PerSeptive Biosystems Inc. v. Pharmacia Biotech Inc., 225 F.3d 1315 (Fed. Cir. 2000).

A Final Warning and a Look to the Future

Inequitable conduct cannot be purged after a patent issues. One cannot overcome prior misconduct, for example, by disclosing an omitted reference in a reissue application or a re-examination. See, e.g., Bristol-Myers Squibb Co., 326 F.3d at 1237; Molins PLC, 48 F.3d at 1182. When aware of misconduct, a practitioner should act quickly to cure it. While one could conceivably obtain allowance and hence secure the presumption of validity without such a cure, that person may face a big price down the road, given the potential penalties of enhanced damages, special damages, disciplinary action, and even disbarment.

Lastly, as always, a practitioner should be aware of changes in the law. While the Patent Reform Act has languished in Congress, versions of the bill stand to dramatically change major aspects of inequitable conduct proceedings. The introduced bill would codify the duty of candor of the PTO found in 37 C.F.R '1.56 and would remove inequitable conduct proceedings from the court and place them before the PTO with provisions for civil penalties. Further, a 'but for' standard would be applied to issues of materiality, and issues of fraud by attorneys would not be attributable to the patent owner. In any case, adherence to the above guidelines should provide a path through the minefield.

James DeZazzo, Ph.D., is an associate with Hunton & Williams LLP in New York and is registered to practice before the USPTO. Dr. DeZazzo focuses his practice in the areas of patent litigation, prosecution, opinion work, and counseling. With a doctorate in cellular and molecular biology and experience as a senior staff scientist at a startup biotechnology company, Dr. DeZazzo has expertise in many technical disciplines, including genetics, pharmaceutics, transgenics, signal transduction, molecular neurobiology, animal behavior, and genomics. Stefan Miller, Ph.D., is a registered patent agent before the USPTO and holds a doctorate in organic chemistry from Yale University. Dr. Miller is a second-year law student at New York University and clerks at the firm. The views expressed in this article are the opinions and not the legal advice of the authors and do not represent the views of Hunton & Williams, its clients, or its affiliates.

'It has now been surprisingly discovered ' '

With these words in Purdue Pharma's U.S. Patent Nos. 5,656,295, 5,508,042 and 5,549,912, Endo Pharmaceuticals asserted a basis to challenge the enforceability of Purdue's controlled-release oxycodone formulations due to inequitable conduct. Purdue Pharma L.P. v. Endo Pharms., Inc. , 438 F.3d 1123 (Fed. Cir. 2006).

Inequitable conduct is a showing that applicants for a patent have failed in their duty to prosecute their patent application before the U.S. Patent and Trademark Office ('PTO') with candor and in good faith. 37 C.F.R. '1.56(a). A breach of this duty includes affirmative misrepresentations of a material fact (or submission of false material information) or failure to disclose material information, coupled with an intent to deceive or mislead the PTO. Molins PLC v. Textron, Inc. , 48 F.3d 1172, 1178 (Fed. Cir. 1995). A showing of inequitable conduct as to a single claim or a single applicant can render the entire patent unenforceable. See, e.g., Hewlett-Packard Co. v. Bausch & Lomb, Inc. , 882 F.2d 1556 (Fed. Cir. 1989) (inequitable conduct as to one claim extends to all others) and see, e.g., Syntex (U.S.A) L.L.C. v. Apotex, Inc. , 407 F.3d 1371 (Fed. Cir. 2005) (inequitable conduct by improperly named inventors applied to unnamed, actual inventors).

At trial, while Endo's generic formulation was determined to infringe Purdue's patented product, Purdue's repeated statements to the PTO that it had discovered a formulation with an improved dosing profile were held to be an intentional failure to disclose material facts. Particularly, Purdue's claim to a 'discovery' was based on 'insight without scientific proof.'

Purdue appealed and lost again, at which point it petitioned for a rehearing. In a rare reversal, the same three-person panel of judges on the Court of Appeals for the Federal Circuit ('CAFC') came to a new conclusion as to the degree of materiality and the allowable inference of intent as a result. The court reaffirmed that Purdue failed to disclose what was behind its 'surprising discovery' and that as such the threshold of materiality for inequitable conduct was met. However, the panel also noted that it was not highly material because Purdue 'did not expressly misrepresent to the PTO' that it had obtained experimental results. Noteworthy was Purdue's attempt to argue that even if material, its omissions were not relevant since the examiner could have allowed the claims based on other arguments made to distinguish the claims over the prior art. In rejecting a 'but-for' test, the court reiterated its stance that materiality is wide in scope and extends beyond matters pertaining to patent issuance. The court also emphasized that while materiality is a factor in its determination of ine-quitable conduct, it cannot be the only factor since intent is a separate and necessary determination in which a threshold showing must also be made. There must also necessarily be culpability, and such culpability must arise from more than inadvertence, carelessness, or gross negligence. Kingsdown Medical Consultants v. Hollister, Inc ., 863 F.2d 867 (Fed. Cir. 1988) (en banc) (holding that 'gross negligence does not of itself justify an inference of intent to deceive; the involved conduct, viewed in light of all the evidence, including evidence indicative of good faith, must indicate sufficient culpability to require a finding of intent to deceive.')

The trial court had found that in internal documents Purdue revealed its concerns at meeting the higher evidentiary standards before the FDA and utilized these concerns as indicative of intent. The appellate court clarified that since FDA evidentiary standards are by their nature higher than those before the PTO, these concerns were only marginally relevant as to Purdue's alleged intent to deceive the PTO. Further, the court reaffirmed that evidence of Purdue's good faith was improperly discounted at trial.

Purdue and Endo have now settled the patent infringement suit (which was announced Aug. 28, 2006). According to the agreement, Endo will stop selling infringing versions of its OxyContin by the end of the year. In exchange, Purdue Pharma will not pursue damages against Endo for Endo's past infringement.

As illustrated by this case, a patent practitioner must be aware of the plethora of facts and issues the PTO considers material and therefore disclosable. The consequences of an inequitable conduct charge, if sustained, are dire. It can lead to the total unenforceability of a patent and even related patents. See, e.g., Consolidated Alum. Corp v. Foseco Int'l Ltd. , 910 F.2d 804 (Fed. Cir. 1990) (holding that inequitable conduct as to one patent may so permeate the others that all are unenforceable). Indeed, it is a trap for the unwary and has become a frequent counter-charge in infringement cases. The Federal Circuit has stated that 'the habit of charging inequitable conduct in almost every major patent case has become an absolute plague.' Burlington Indus. Inc. v. Dayco Corp. , 849 F.2d 1418, 1422 (Fed. Cir. 1988), and that '[i]nequitable conduct is not, or should not be, a magic incantation to be asserted against every patentee.' FMC Corp. v. Manitowoc Co. , 835 F.2d 1411, 1415 (Fed. Cir. 1987).

An inequitable conduct charge can also have consequences far beyond unenforceability of a patent; it may lead to devastating professional sanctions as well. This article provides the patent practitioner with suggestions to potentially avoid these pitfalls.

Practitioner Tips

• Advise inventors of their duty. Inventors should be reminded, at a minimum in a disclaimer included in all communications, to disclose all information material to patentability and that such a duty continues throughout prosecution of their patent. An inventor should be told to consider the scope of materiality as broadly as possible.
• Be careful with examples and descriptions in the specification. Avoid misidentification or misinterpretation of any prior art in any background sections, as well as inaccurate or unjustified technical statements in patent specifications. Draft examples to avoid any misleading inferences; eg, 'paper examples' should be drafted in the present tense to avoid giving the impression that they were actually carried out. See Hoffmann-La Roche, Inc. v. Promega , 323 F.3d 1354, 1363 (Fed. Cir. 2003).
• Be careful when drafting and submitting declarations. When submitting test results, it is crucial that a sound scientific basis exists for excluding certain experimental data. See, e.g., Glaxo Inc. v. Novopharm Ltd. , 52 F.3d 1043 (Fed. Cir. 1995). In addition, a practitioner must make sure that experts or other third parties who submit a declaration reveal any conflicts of interest. See, e.g., Ferring B.V. v. Barr Labs., Inc , 437 F.3d 1181 (Fed. Cir. 2006); Refac International, Ltd. v. Lotus Devel-opment Corp. , 81 F.3d 1576 (Fed. Cir. 1996). A practitioner should also ascertain whether the declarant has made statements elsewhere that potentially contradict the information in the document to be submitted to the PTO. See, e.g., Pharmacia Corp. v. Par Pharma-ceuticals, Inc. , 417 F.3d 1369 (Fed. Cir. 2005). If so, then the basis for such inconsistency should be investigated and disclosed.
• Monitor related foreign applications. Actions of foreign attorneys will be imputed to the U.S. practitioner; that is, the duty of disclosure applies equally to foreign practitioners who represent claims in the U.S. PTO through local U.S. firms. See M.P.E.P. '2001.06(a). U.S. pa-tents have been declared unenforceable because the foreign attorney did not disclose to the PTO prior art that was cited by a foreign patent office during prosecution of the corresponding foreign application. See Gemveto Jewelry Co. v. Lambert Bros., Inc. , 542 F. Supp. 933, 943 (S.D.N.Y. 1982). Consequently, a practitioner must make sure to disclose to the PTO all relevant information stemming from prosecution of a related, foreign application.
• Consider all sources of material information. A fundamental and often ignored guideline is that material information encompasses much more than prior art under 35 U.S.C. '102. Rule 56 emphasizes that materiality embraces 'all information known … to be material to patentability,' including, but not limited to, information on small entity status, inventorship, enablement, written description, best mode, and priority. See M.P.E.P. '2001.04. See also Bristol-Myers Squibb Co. v. Rhone-Poulenc Rorer, Inc. , 326 F.3d 1226, 1241 (Fed. Cir. 2003). A practitioner should therefore have the big patentability picture in mind when carrying out a materiality analysis. To base such an analysis only on prior art under '102 is to potentially invite a later charge of inequitable conduct. A practitioner must also remember that the duty of disclosure extends to trade secret, proprietary, and protective order materials that are material and non-cumulative.
• Consider information a reasonable examiner would deem im-portant as to issuance of a patent to be material. The Federal Circuit has utilized a number of tests over the years ranging from a reasonable examiner standard to the more narrow rule embodied in PTO Rule 56. Despite variations on the standard, the court has stated that all standards are applicable 'to the extent that one standard requires a higher showing of materiality; the requisite finding of intent may be lower.' See Digital Control Inc., v. The Charles Mach. Works, 437 F.3d 1309 (Fed. Cir. 2006). The broadest rule should therefore be considered.
• Select references according to their relevance. A practitioner should adopt a generous screening approach that favors inclusion for several reasons. First, the standard for materiality is not whether the applicant personally regards prior art as material; it is whether one of ordinary skill in the art would have so regarded a reference. See, e.g., Argus Chem. Corp. v. Fibre Glass-Evercoat Co. , 759 F.2d 10 (Fed. Cir. 1985). An applicant should therefore avoid subjective criteria for selecting references. Second, a reference can be material even though it does not disclose all of the limitations of a claimed invention. See, e.g., Molins PLC v. Textron, Inc ., 48 F.3d 1172 (Fed. Cir. 1995). The essential inquiry in determining obviousness, for example, is whether the teachings of a reference, in combination with other prior art, 'would have rendered the claimed invention obvious to one of ordinary skill in the art.' Life Technologies v. Clontech , 224 F.3d 1320 (Fed. Cir. 2000). For these reasons, the practitioner should submit all relevant references, eliminating non-cumulative references that are clearly irrelevant and cumulative references that are marginally relevant. At the same time, a practitioner should not submit so many marginally relevant references as to suggest that a key reference has been buried. See, e.g., Molins PLC, 48 F.3d 1172; Penn Yan Boats, Inc. v. Sea Lark Boats, Inc. , 479 F.2d 1328 (5th Cir. 1973). Such a buried reference can infer misconduct; therefore, the PTO advises practitioners to highlight those references that may be of most significance. See M.P.E.P. '2004(13).
• When in doubt, disclose. Applicants are not penalized for submitting references that may ultimately be deemed irrelevant or not material. Indeed, the PTO recognizes the advantage in submitting such information 'because it will result in a strengthened patent and will avoid later questions of materiality and intent to deceive.' M.P.E.P. '2001.04. Similarly, the CAFC has advised that '[I]n close cases, where the materiality of the information is uncertain, disclosure is required.' Brasseller, U.S.A. I, L.P. v. Stryker Sales Corp. , 267 F.3d 1370 (Fed. Cir. 2001). Moreover, the PTO points out that its rules facilitate such submissions in at least two ways. First, the burden for most submissions is minimal because the PTO has eliminated the requirement for a 'concise statement of the relevance of each item of information submitted in an information disclosure statement.' Second, submitting such information in an Information Disclosure Statement is not an admission 'that the information cited in the statement is, or is considered to be, material to patentability [under Rule 56].' In fact, references are commonly submitted in an IDS accompanied by such a disclaimer. Where an IDS concerns a patent application that is related to other co-pending U.S. patent applications, then the applicant must bring the co-pending patent applications to the examiner's attention. Under such circumstances, the CAFC has cautioned that 'the examiner of a particular application is not necessarily aware of other applications which are 'material to patentability' of the application in question.^' M.P.E.P. '2001.06(b). For this reason, information in related patent applications has been deemed material. An adverse decision by an examiner in a related but undisclosed case, for example, will meet the threshold for materiality. See, e.g., Dayco Products v. Total Containment , Inc . 329 F.3d 1358 (Fed. Cir. 2003). A failure to cite such co-pending patent applications can support an inference of deceptive intent. See Akron Polymer Container Corp. v. Exxel Container, Inc. , 148 F.3d 1380 (Fed. Cir. 1998). Similarly, prior art references cited in a related patent application should be made of record in a subsequent patent application if such prior art references are 'material to patentability' of the subsequent application.

When a cited reference is not in English, the applicant has two options: First, the applicant can provide a statement explaining the document's relevance. Such a statement should be as brief as possible. This will reduce the risk that an adversary will cite the statement against you, arguing that it is incorrect, misleading, deceptive, etc. The second option is to submit an English translation for at least the relevant part of the document. When submitting such a summary, a practitioner must be sure that the untranslated portions do not include material information. Otherwise, the practitioner may face liability for deceptive intent for submitting misleading or incorrect information. See Semiconductor Energy Laboratory Co., Ltd. v. Sam-sung Electronics Co., Ltd. , 204 F.3d 1368 (Fed. Cir. 2000).

• Disclose information as needed throughout prosecution. A practitioner must be aware that the duty of candor spans the entire course of patent prosecution, applying to every version of each claim 'until the claim is cancelled or withdrawn from consideration.' Baxter International Inc. v. McGaw Inc. , 149 F.3d 1321 (Fed. Cir. 1998). A breach of the duty early in prosecution may therefore lead to unenforceability of all claims that issue from that application as well as from related applications. For this reason, a practitioner should be careful to disclose all known information that is material to the patentability of the original claims ' even if the claims that ultimately issue have a different form.
• Disclose related litigation and PTO administrative proceedings. When the subject matter of a patent application 'is or has been involved in litigation, the existence of such litigation and any material information must be brought promptly to the attention of the PTO.' M.P.E.P. '2001.06(c). Such information may include evidence that bears on prior art, fraud, inequitable conduct, and the violation of duty of disclosure. To meet these requirements, it may not be necessary initially to provide the actual court documents. The M.P.E.P. provides that at a minimum, it is sufficient to 'call to the attention of the Office the litigation, the nature of allegations that bear materially on the original patent, and the nature of the pertinent litigation materials so that the Office can evaluate the need to ask for further materials in the litigation.' Similarly, it is necessary to
  disclose prior PTO Board decisions, as such decisions may bear on the patentability of claims in a current application. See, e.g., Li Second Family Limited Partnership v. Toshiba Corp. , 231 F.3d 1373 (Fed. Cir. 2000); Affymetrix, Inc. v. PE Corporation, 2002 WL 1049485 (S.D.N.Y. 2002). Such disclosure may also apply to an interference proceeding that was settled if that settlement did not bar the accused infringer from challenging validity of the disputed patent. See Ad-vanced Cardiovascular Systems, Inc. v. Medtronic, Inc. , 265 F.3d 1294 (Fed. Cir. 2001).
• Seek remedial measures. An in-ference of intent cannot be based on materiality alone. Thus, by always conducting actions in good faith, a practitioner may guard against allegations of inequitable conduct. Nevertheless, when the breach is highly material, evidence of good faith will do little to rebut an inference of intent if other factors are present. If one discovers an error during prosecution, arising from some form of possible misconduct, disclose that information promptly. Curing the misconduct is possible if an applicant advises the PTO of the possible fraud and the actual facts and establishes patentability based on the actual facts. Such a cure, however, must be based on clear, unequivocal, and convincing evidence. Rohm & Haas Co. v. Crystal Chem. Co. , 722 F.2d 1556 (Fed. Cir. 1983). Such curative measures must therefore include full disclosure to the PTO. Merely amending the claims will not suffice. See, e.g., PerSeptive Biosystems Inc. v. Pharmacia Biotech Inc. , 225 F.3d 1315 (Fed. Cir. 2000).

A Final Warning and a Look to the Future

Inequitable conduct cannot be purged after a patent issues. One cannot overcome prior misconduct, for example, by disclosing an omitted reference in a reissue application or a re-examination. See, e.g., Bristol-Myers Squibb Co., 326 F.3d at 1237; Molins PLC, 48 F.3d at 1182. When aware of misconduct, a practitioner should act quickly to cure it. While one could conceivably obtain allowance and hence secure the presumption of validity without such a cure, that person may face a big price down the road, given the potential penalties of enhanced damages, special damages, disciplinary action, and even disbarment.

Lastly, as always, a practitioner should be aware of changes in the law. While the Patent Reform Act has languished in Congress, versions of the bill stand to dramatically change major aspects of inequitable conduct proceedings. The introduced bill would codify the duty of candor of the PTO found in 37 C.F.R '1.56 and would remove inequitable conduct proceedings from the court and place them before the PTO with provisions for civil penalties. Further, a 'but for' standard would be applied to issues of materiality, and issues of fraud by attorneys would not be attributable to the patent owner. In any case, adherence to the above guidelines should provide a path through the minefield.

James DeZazzo, Ph.D., is an associate with Hunton & Williams LLP in New York and is registered to practice before the USPTO. Dr. DeZazzo focuses his practice in the areas of patent litigation, prosecution, opinion work, and counseling. With a doctorate in cellular and molecular biology and experience as a senior staff scientist at a startup biotechnology company, Dr. DeZazzo has expertise in many technical disciplines, including genetics, pharmaceutics, transgenics, signal transduction, molecular neurobiology, animal behavior, and genomics. Stefan Miller, Ph.D., is a registered patent agent before the USPTO and holds a doctorate in organic chemistry from Yale University. Dr. Miller is a second-year law student at New York University and clerks at the firm. The views expressed in this article are the opinions and not the legal advice of the authors and do not represent the views of Hunton & Williams, its clients, or its affiliates.