An effective litigation tool available that may be available to an accused infringer is the defense of inequitable conduct, which seeks to ensure against fraudulent procurement of patents. Every individual associated with the filing and prosecution of a U.S. application owes to the U.S. Patent and Trademark Office a duty of candor and good faith.1 A finding that one has breached this duty can render a patent unenforceable against past, present, and future infringers, and might even affect the enforceability of related patents.

The America Invents Act, signed into law on Sept. 16, 2011, ushered in an array of patent reforms. One, supplemental examination, seeks to purge putative instances of inequitable conduct prior to litigation by allowing patent owners to submit prior art and explanatory statements to the USPTO after patent issuance.2

According to 35 U.S.C. § 257, a patent owner may file a request for supplemental examination asking the USPTO to consider, reconsider, or correct information in a patent or its file history. Within three months, the director will determine whether the information presented in the request raises a substantial new question of patentability. If so, the examiner will order ex parte re-examination in view of the submitted evidence, during which the patent owner can argue for patentability of the claimed invention and/or amend the issued claims. Importantly, anything considered by the USPTO in the request for supplemental examination or the ensuing ex parte re-examination is, by statute, barred as the basis for a later finding of inequitable conduct.3

Still, there are important limitations. First, supplemental examination becomes unavailable once inequitable conduct has either been plead in a patent litigation,4 or raised in a paragraph IV notice letter.5 Moreover, any cleansing effect of a supplemental examination occurs only once the supplemental examination proceeding and any ex parte re-examination ordered therefrom has drawn to a close. So if the patent becomes involved in litigation before the USPTO completes its review, the accused infringer may raise an inequitable conduct defense including any information that the patent owner asked the USPTO to consider in its request for supplemental examination.6 In that event, however, a patent owner may request a stay of the litigation pending the outcome of the supplemental examination/subsequent re-examination.7

Chemical Supplemental Examination Requests

In light of the seemingly powerful tool that supplemental examination provides to purge putative instances of inequitable conduct from a patent’s prosecution history, we were curious to see how supplemental examinations have fared to date in the chemical arts.

Due to the specialized interplay between the patent system and regulatory approval of new pharmaceutical products, patent owners in this field may be able to make reasonably accurate predictions of when they will receive patent validity challenges. As a result, such patent owners may be well-suited to submit an appropriate request for supplemental examination before their patents become involved in a potential litigation.

According to the USPTO 2016 annual report, 34 chemical-related supplemental examination requests were filed between 2014 and 2016.8

Figure 1: USPTO 2016 Annual Report Supplemental Examination Filings By Technology (2014-2016), Table 13B9

While the USPTO report does not list which supplemental examination requests it characterized as chemical-related, we reviewed a list of all supplemental examination requests filed and selected the cases we believe account for the 34.10 Using PACER, we pulled those 34 chemical-related supplemental examination requests to see if there are any notable trends.

The chart below, using data from the USPTO’s 2016 annual report Table 13B, shows that the overall rate at which the USPTO is finding a substantial new question of patentability (SNQ) in requests for supplemental examination is 52 percent (73/141).11

Figure 2: USPTO 2016 Annual Report Supplemental Examination Filings and SNQ Found (2014-2016)12

In contrast, for chemical supplemental examination requests, the rate is significantly higher: 76 percent (26/34).

Figure 3: Finnegan Research of Chemical Supplemental Examination Requests13

In the 26 supplemental examination petitions for which a SNQ was found, 24 have had a re-examination certificate issued. And in nearly half of those cases, no original claims remained after the reexamination concluded.

Figure 4: Chemical Supplemental Examination Requests in Which SNQ Found14

Chemical Supplemental Examinations Involving Related Litigation or PTAB Proceedings

Of the 34 chemical supplemental examination requests filed, most do not have any related litigation, and only one had a related Patent Trial and Appeal Board proceeding.

Figure 5: Chemical Supplemental Examination Requests and Related Litigation

Five of the requests for supplemental examination in the chemical arts had a related infringement litigation.15 In three of those cases, the litigations were dismissed without prejudice. In two of those cases, the litigations were dismissed without prejudice prior to the requests for supplemental examination.16

In the third, 96/000,053 (U.S. Pat. No. 8,440,119),17 dismissal without prejudice in the two related litigations was requested by the patent owner after the litigations were stayed pending the ex parte re-examination, but before a re-examination certificate issued. The re-examination certificate subsequently issued and resulted in five claims being canceled, four claims being amended, and six new claims being added. Since we have been unable to identify a subsequent related litigation, we assume that there was no basis on which to assert infringement in view of the amended and new claims.18

In the other two supplemental examination requests involving related litigation, the USPTO ordered ex parte re-examination, issued re-examination certificates, and the patent owners then sued for patent infringement. In one, 96/000,018 (U.S. Pat. No. 7,631,671), the patent owner requested supplemental examination in light of a 2002 blueprint of a diagram and an expert declaration discussing the blueprint and explaining that it provided evidence of a prior public use of the claimed invention. Re-examination was ordered for 12 of the original 54 claims.

In its decision on supplemental examination, the USPTO determined that those 12 claims were not entitled to the asserted priority date. The USPTO thus concluded that a reasonable examiner would have considered the diagram and declaration important in determining patentability.

The patent owner then canceled those 12 original claims in the ex parte re-examination proceeding, and a re-examination certificate was subsequently issued. The patent owner then filed an infringement litigation19 based on the remaining claims that had not been subject to ex parte re-examination.

In response, the defendants counterclaimed for unenforceability due to inequitable conduct, alleging that the “inventors and a prior owner of the patents failed to disclose at least three prior art systems to the USPTO, and a letter written by one of the inventors.” The defendants further alleged that the declaration submitted with the supplemental examination request was false. As of Jan. 25, 2018, the case was not yet resolved.

The other case in which the patent owner brought an infringement litigation after completing supplemental examination and receiving a re-examination certificate, 96/000,045 (U.S. Pat. No. 6,346,532), has a currently-pending related abbreviated new drug application litigation.20 The request for supplemental examination included several references, including prosecution history file excerpts, meeting notes, a study report, a research and development flowchart, a monthly progress report, a Japanese patent application, nonpatent literature articles, a Patent Cooperation Treaty application, and a Rule 132 declaration.

The USPTO determined that the request raised a substantial new question of patentability with respect to 12 of the 14 claims based on the Japanese application, the PCT application, and the articles, and ordered ex parte re-examination. The USPTO determined that the other items submitted with the request did not raise a substantial new question of patentability.

Original claims 1-6 and 9 were compound claims, claims 7-8, 10-12 were composition claims, and claims 13-14 were method of treatment claims. Claims 6 and 12 were not re-examined. The re-examination terminated with claims 2, 7, and 8 canceled, claims 1, 3-5, and 11 amended, and new claims 15-17 added.

A re-examination certificate subsequently issued, and complaints for patent infringement were filed over a year and a half later. The litigations were consolidated, and, as of Jan. 25, 2018, were not yet resolved.

If the patents at issue in these two cases in which infringement litigations were brought after completion of supplemental examination are upheld as valid, infringed, and enforceable by the respective district courts, these cases may provide examples of patent owners successfully using supplemental examination to “purge” alleged inequitable conduct and then successfully enforce the resulting re-examination patents. It will be interesting to see whether the defendant’s inequitable conduct counterclaims in the first case survive in light of the completed supplemental examination.

The supplemental examination, 96/000,071, with a related PTAB proceeding IPR2014-01002 (U.S. Pat. No. 96/000,071), warrants discussion. The USPTO found a substantial new question of patentability and instituted ex parte re-examination on just one claim (claim 10). Claim 10 also was the only claim for which the IPR was instituted. The references submitted in the supplemental examination request overlapped with those on which PTAB based its institution decision in the corresponding IPR.

The inter partes review petition was filed June 20, 2014, and instituted on Dec. 29, 2014. The request for supplemental examination was filed about two weeks later, on July 3, 2014, and submitted three U.S. patents, six nonpatent literature articles, and two of the petitioner’s expert declarations that were filed in the June 2014 IPR. Finding a SNQ of patentability based on four articles and three U.S. patents, the USPTO ordered ex parte re-examination. The USPTO did not find a SNQ based on the declarations, which were not prior art under § 102.

In February 2015, the petitioner asked the PTAB to stay the co-pending re-examination (and a co-pending reissue application, which was suspended pending the re-examination) in light of the IPR. The statue gives the PTAB discretion for “stay, transfer, consolidation, or termination of any such matter or proceeding” before them.21 The PTAB declined, however, due to the differences in the proceedings and due to new testimony in the IPR.22 The PTAB also declined the patent owner’s motion to stay or terminate the IPR in light of the reexamination.23 Interestingly, one of the reasons the PTAB gave for denying the motion to stay the IPR was that the IPR was mandated to terminate within a year while the re-examination had no time limit.24

After re-examination, claim 10 was canceled, and 14 newly added claims were held patentable. The re-examination certificate issued on Nov. 12, 2015.

Meanwhile, on Nov 2, 2015, the PTAB issued a final written decision in the related IPR proceeding holding that claim 10 had not been shown to be unpatentable over the cited references. So claim 10 had survived the IPR, but was canceled during ex parte re-examination!

These PTAB/re-examination matters provide a good reminder that patent owners should carefully consider the timing of any effort at supplemental examination if they might soon seek to enforce the patent or if there is any indication that a third party might imminently file an IPR. While a decision on the request for supplemental examination must be made in three months, the patent could be tied up in the USPTO for over a year if the director orders ex parte re-examination or if a petition for IPR is filed and subsequently granted. And appealing an adverse decision in the ex parte re-examination could further delay any effort to enforce a patent.

Strategic Use of Supplemental Examination

The authors suggest assessing the enforceability of valuable patent portfolios to determine whether requesting supplemental examination is an appropriate strategy in the particular circumstances. In the pharmaceutical industry, patent holders might want to make such an analysis when listing a patent in the U.S. Food and Drug Administration’s Orange Book or even well before then. Patent owners may expect that an Orange Book-listed patent will be litigated, but usually not for several years, providing good odds that a supplemental examination (and any subsequent ex parte re-examination) would run its course before the patent owner seeks to enforce the patent against accused infringers in Hatch-Waxman litigation.

The USPTO places high burdens on patent owners considering a request for supplemental examination.25 First, the USPTO has set a steep fee for the procedure.26 Second, the USPTO requires patent owners to make, on the record, fairly substantial admissions regarding errors made during prosecution. Third, it limits the number of items that a patent owner may raise in a request for supplemental examination. In view of these limitations, it is not surprising that the use of supplemental examination by patent holders has been relatively scarce, at least compared to another America Invents Act post-grant proceeding, IPR.

Interestingly, the AIA may have unintentionally provided other options for curing inequitable conduct. For instance, in amending the reissue sections of the statute, Congress removed the requirement that any errors corrected through reissue were made without deceptive intent.27 The Federal Circuit has noted that inequitable conduct cannot be cured through reissue. But if the USPTO considers an item of information during a reissue proceeding and still reissues the patent, an accused infringer would be hard-pressed to argue that the item of information was “but for” material under the Therasense test for inequitable conduct.28

Thus, Congress’ removal of the “without deceptive intention” requirement from the reissue statute, in combination with the Federal Circuit’s en banc decision in Therasense requiring but-for materiality to establish inequitable conduct, arguably opens the door for patent owners to address the prong of but-for materiality of inequitable conduct via reissue.

In summary, if used strategically, supplemental examination can provide a powerful tool for chemical patent owners to add to their armamentarium of options for Orange Book-listed patents when conducting a due diligence analysis of their patent estate prior to Orange Book listing. But given that there are only 30 days provided for Orange Book listing after approval or after a subsequent potential Orange Book listable patent issues, it could be wise to consider the need for a request for supplemental examination well prior to the “due date” for listing in the Orange Book. Under such circumstances, a request for supplemental examination could provide a mechanism for such patent owners to strengthen their patents before listing in the Orange Book to position the patentee for assertion against generic manufacturers in Hatch-Waxman litigation.